August 2006 - Silicon Chip Online

Outer Front Cover
Contents
Publisher's Letter: Video projectors give a true home theatre experience
Feature: Video Projector Survey by Barrie Smith
Feature: Television – The Elusive Goal; Pt.3 by Kevin Poulter
Project: Novel PICAXE LED Chaser Clock by Ron Russo & Clive Seager
Project: Build A Magnetic Cartridge Preamplifier by John Clarke
Project: An Ultrasonic Eavesdropper by Jim Rowe
Feature: MoTeC Race Car Data logging, Pt.2 by Julian Edgar
Project: Multi-Throttle Control For PC Flight Simulators by Robert Gott
Project: Mini Theremin Mk.2; Pt.2 by John Clarke
Vintage Radio: The HMV B11A 5-valve mantel receiver by Rodney Champness
Salvage It: The good bits inside flatbed scanners by Julian Edgar
Book Store
Advertising Index
Outer Back Cover

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SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.19, No.8; August 2006 SILICON CHIP www.siliconchip.com.au Features 8 Video Projector Survey Looking to buy a video projector for your home theatre set-up? Don’t do it until you’ve read this authoritative survey – by Barrie Smith Comprehensive Video Projector Survey – Page 8. 24 Television – The Elusive Goal; Pt.3 The first 25 years are regarded as the “Golden Age of TV” in Australia. Here’s a nostalgic look back over those years – by Kevin Poulter 83 MoTeC Race Car Data logging, Pt.2 Making sense of all the data that’s monitored by the sensors – by Julian Edgar Pro jects To Build 40 Novel PICAXE LED Chaser Clock It’s got hands to indicate hours, minutes and seconds, plus chaser LEDs that stop and freeze at the seconds hand – by Ron Russo & Clive Seager 48 Build A Magnetic Cartridge Preamplifier Want to play back your old LPs and 78s, or convert them to CD or MP3 files? This high-performance preamplifier will let you do the job – by John Clarke 72 An Ultrasonic Eavesdropper Build this unit and listen to a whole new range of sounds, like the supersonic whine of a gas leak or echo-location chirps from bats – by Jim Rowe Novel PICAXE LED Chaser Clock – Page 40. 90 Multi-Throttle Control For PC Flight Simulators Add this very simple multi-throttle controller (for up to four engines) and start flying with the big boys – by Robert Gott 102 Mini Theremin Mk.2; Pt.2 All the construction and adjustment details – by John Clarke Special Columns 56 Serviceman’s Log The dreaded black spot disease – by the TV Serviceman Magnetic Cartridge Preamplifier – Page 48. 96 Circuit Notebook (1) Infrared Remote Extender; (2) PICAXE Battery Protector; (3) MainsDerived Timebase; (4) Automatic Daytime Running Lights; (5) Cheap 1W Luxeon LED Driver 112 Vintage Radio The HMV B11A 5-valve mantel receiver – by Rodney Champness 117 Salvage It! The good bits inside flatbed scanners – by Julian Edgar Departments 2 4 55 69 Publisher’s Letter Mailbag Order Form Product Showcase siliconchip.com.au 122 125 126 128 Ask Silicon Chip Notes & Errata Market Centre Ad Index An Ultrasonic Eavesdropper – Page 72. Main cover photo courtesy Len Wallis Audio. August 2006 1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 Publisher’s Letter Video projectors give a true home theatre experience This month, we have a major feature article on video projectors, starting on page 8. It surveys all the currently available high-definition video projectors. This has been a mammoth task and inevitably, by the time this issue goes on sale, there may be some newer models on the market. That, of course, is a permanent hazard whenever you are trying to take a survey of rapidly moving technology. And make no mistake, video projector technology has moved very rapidly in the last few years while the prices have dropped markedly. A few years ago there were few people who could contemplate owning a realistic hometheatre system but now anyone who is thinking of buying a large plasma or LCD set can buy a high quality video projector instead and probably save money at the same time. I said as much in our February 2006 issue and following my own advice, recently purchased an LCD video projector. What a wonderful acquisition it has been. Every time we sit down to watch a DVD I just marvel at the picture quality and the mind-boggling technology which produces it. And this is without high-definition DVDs which will no doubt give a further quality improvement. As one who well remembers the early days of TV and the common advice as to how far away you should sit from a 21-inch TV set to avoid seeing line structure, the picture quality we achieve today on a screen (actually just the wall) several metres wide is quite remarkable. Screen door effect? Not a problem! And yet only a year ago most LCD projectors could have been criticised for this drawback. Certainly, you still need a darkened room to enjoy a video projector but in my case at least, that seems to be part of the ritual; you are not merely watching TV but having a theatre experience in your own home. Apart from having better picture quality than in a cinema, you also don’t have to endure sound levels that are too loud, the sounds and smell of popcorn or even having to cope with tall people sitting in front of you! So why compromise with a plasma or LCD TV set? Or even with one of the rear projection sets? Provided you have a suitable blank wall or space for a large screen, you can have a high-definition video projector, for a similar or even less amount of money. Then you can be enjoying really large pictures in your own home. Now that is a true home theatre experience. Leo Simpson Note: SILICON CHIP has moved to new offices at Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Phone (02) 9939 3295; fax (02) 9939 2648. * Recommended and maximum price only. 2 Silicon Chip siliconchip.com.au                                         MAILBAG Mobile phones don’t cause brain cancer Contrary to the claim in your Publisher’s Letter (“Mobile phones have increased risk of brain damage”) in the June 2006 issue, there is no biological, medical or statistical basis to assert a link between mobile phone use and brain cancer. Potential human health impacts of radio frequency energy have been studied in great detail over the past 50 years. This has resulted in a large body of scientific literature in this field, covering laboratory, clinical and epidemiological research. Comprehensive reviews of 2200 research publications, including more than 410 studies specifically on mobile phones and base stations by governments and health authorities, continue without exception, to find there is no substantiated scientific evidence of health effects. The UK research team of the largest study ever conducted on brain cancer and published earlier this year concluded: Overall, we found no raised risk of glioma (brain cancer) associated with regular mobile phone use and no association with time since first use, lifetime years of use, cumulative hours of use, or number of calls. This study is part of a 13-nation INTERPHONE project coordinated by the International Agency for Research on Cancer (IARC). Once all the studies Possible risk from cordless phones Your comment on brain damage from mobile phones is timely. There was much interest in this topic several years ago but things seem to have gone quiet in the intervening period. If one doesn’t use a mobile, then the alternative (immobile?) phone line to a local exchange may represent a similar hazard when accessed via the ubiquitous cordless phone. From the scant technical data for these phones, currently available units appear to employ similar fre- 4 Silicon Chip are completed, the IARC, an agency of the World Health Organisation, will do a combined analysis of the research which is expected to be published later this year. From the results collected to date, the individual INTERPHONE studies, including the Swedish and UK studies mentioned in your letter, have all concluded there is no overall risk of brain tumours from mobile phone use. Your publisher’s claim that there is more and more evidence of a link is false and misleading. Moreover, it is inappropriate to selectively report non-statically valid results or partial results and not also provide overall results of these studies. Once completed, it is expected that the INTERPHONE project will have examined 6000 cases of the two most common types of brain cancer – glioma or meningioma. With regards to ear cancer, the researchers from the Denmark, Finland, Norway, Sweden and UK INTERPHONE project teams recently published their research involving more than 4000 people in the British Journal of Cancer and announced: The study found no relation between the risk of acoustic neuroma (ear nerve cancer) and the number of years for which mobile phones had been used, the time since first use, the total hours of use or the total number of calls, nor were there any relations separately for quencies and digital techniques to mobiles and are packaged similarly with close ear and head contact. As many of us engage in much longer conversations using a cordless phone than with a mobile, the cumulative effect may be equally damaging. Perhaps you have access to sufficient technical data to reassure cordless users of their safety. Otherwise, we may be persuaded to return to an old VHF cordless or plug in a corded phone. Andrew Hanby, Bingie, NSW. analog or digital phone use. Regarding the Swinburne University of Technology study on brain function, the results from this study are inconsistent with previous research on brain activity and the small differences found could be due to normal biological variation or statistical noise. In fact previous studies have found an increase rather than a decrease in reaction times. Over the past five years several studies looking at effects of mobile phones on human cognitive functions have been conducted by the Centre for Cognitive Neuroscience at the University of Turku in Finland with larger numbers of participants. These studies have not been able to replicate the results of the earlier smaller studies. In relation to the effects of mobile phones on brain function, the World Health Organisation has said: These effects are small and have no apparent health significance. More studies are in progress to try to confirm these findings. When studies find results which are novel, such as with this one, the well established scientific processes of replication and validation are required before the results can be accurately assessed within the whole body of scientific evidence. The importance of replication has recently been demonstrated in Australia by the results of the research at Adelaide’s Institute of Medical and Veterinary Science (IMVS). The IMVS research could not reproduce the results of a 1997 pilot study that found digital mobile phone emissions doubled the cancer rate in geneticallyengineered, cancer-prone mice. Despite the disregard shown for this process in your Publisher’s Letter, the mobile phone industry continues to endorse the importance of sound, peerreviewed and replicated research so siliconchip.com.au that people can be assured of the safety of mobile phone technologies. The gratuitous comparisons with the tobacco industry ignore the overwhelming body of evidence and have no place in a proper review of scientific fact. The health risks of tobacco are unequivocal, while there is a widespread consensus among international health authorities and governments that radio waves from mobile phones pose no known risks. Your letter also raises the issue of driving and the use of mobile phones and the industry agrees that drivers should never take notes, look up phone numbers, read or send messages. This is an issue we take very seriously and the Australian Mobile Telecommunications Association (AMTA) has distributed widely its “Mobile Phones and Driving Safety Tips” (see http:// www.amta.org.au/?Page=295). Chris Althaus, Chief Executive Officer, Australian Mobile Telecommunications Association. Comment: if you read through the Publisher’s Letter carefully, you will note that there is no claim about mobile phone use and cancer but there is a link between mobile phone use and benign (ie, non-cancerous) tumours! In fact, we believe that since no link between mobile phone use and cancer has been clearly demonstrated, that allows the industry to continue to claim that there is no damage. We believe otherwise. For example, interested readers may care to have a look at http://www.newmediaexplorer. org/chris/2004/10/20/em_fields_on_ brain_tumor_incidence_chemicals_ and_cell_phones.htm Nor have we made any gratuitous link between mobile phones and cigarettes, other than the two industries have used similar techniques of disparagement to nullify criticism. Criticism of early TV article I was very interested to read your feature item “Television, The Elusive Goal” in the June 2006 edition of SILICON CHIP. I am not able to comment on the Australian part of the narrative as a whole, due to my lack of research, however I can inform you that on one aspect the article was in error. I refer siliconchip.com.au to the use of a linear amplifier to increase the 10kW power output from the TV transmitters to 100kW ERP. No amplifier was needed or in fact existed for such a purpose; antenna gain was used, as is the present case. Note the numeric power qualification ERP (effective radiated power, not total radiated power). Now I refer to the author’s comment about Mr J. L. Baird transmitting early TV across the Clyde (Scotland) – wrong! J. L. Baird worked for the Clyde Valley Electrical Power Company around 1916 as an assistant mains engineer, having been excused military service due to ill health. It was not until around 1923 that Baird began experimenting with selenium light cells with the possible application to television during 1923 in various places. Initially, experiments began in Guildhall St. Folkestone, to be followed by further experiments in Hastings (both towns are situated on England’s south coast). Baird did not transmit his early TV experiments but conveyed the signals by cable as raw video; at times telephone lines were used (post 1926). Following the Hastings experiments with the aid of one Victor Mills, it was reported that he moved to Tunbridge Wells and continued with his research until finally he moved to Soho in London’s West End where he “perfected his basic 30-line mechanical system”. The BBC under governmental directive transmitted 30-line TV signals from the London AM broadcast transmitter at Brookmans Park from 1929 until 1934 to a very limited audience. It was stated in your article that the BBC in 1937 proposed a solution to the system of TV to be adopted and it was: “A competitive demonstration to be held between the 240-line Baird system and the Marconi 405-line system.” First of all, it should be noted that the 405-line system was not the Marconi system but the EMI system developed under the leadership of Sir Isaac Schoenberg. Marconi developed the transmitter and antenna only and the two companies together formed a joint holding named Marconi-EMI. Thus the name “EMITRON” for the camera pickup tube, albeit a development of the ICONOSCOPE”. It is not true that the BBC decided Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. AVR573 Single Board Computer This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outputs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au August 2006 5 Mailbag: continued to hold a competitive demonstration in 1937. The British government formed a committee titled “The Television Advisory Committee” (T.A.C.) to look into the progress of television development. Lord Selsdon chaired its first meeting on February 5th, 1935. It was a derivative of this committee and the British government that decided in 1936 to operate the two systems (Baird’s 240line and Marconi-EMI’s 405-line) on a side-by-side trial for three months starting on November 2nd, 1936. The BBC provided the program content production and operators, while the respective equipment suppliers provided the technical expertise and managed the operation. The T.A.C. had determined that the Marconi-EMI system would be chosen as the British TV system as early as January 4th 1937 – the last Baird system transmission was broadcast on January 30th, 1937. It is true that the BBC had representation on the T.A.C. Fishing line fire sensor In the May issue, one of your readers wanted to know what sort of sensors could be used to detect an approaching bushfire. I am not sure but I think it was the CSIRO who used the following idea as part of their research about the rate of spread of bushfires. They used ordinary fishing line tensioned between two posts about half a metre above the ground. The fire burns through the fishing line, causing a weight or spring to be released. This is linked to a switch on a clock or data logger which records the date and time. One advantage of the fishing line method is that long sections can be easily monitored, even in heavy scrub. Disadvantages include false alarms from animals or falling branches. The fishing line may also deteriorate over time and snap from the constant tension. Ray Fitzsimon, Nambour, NSW. 6 Silicon Chip along with the G.P.O. The article also states that CRT tubes were known of before the beginning of the 19th century, again not a realistic statement when discussing TV. The only tube at the turn of the century was the Crookes tube, a laboratory curio that demonstrated the existence of cathode rays. By 1902 Boris Rosing (Russia) had produced extremely crude still shadow images using a modified Crookes tube, again not TV. Braun (Germany) produced the first ultra-crude oscilloscope using a Crookes tube with an electron gun and electromagnets. It was not a high vacuum device and relied on ionisation of residual gases for its operation,. It had no heated cathode and at best may have supported a two or three-line TV system. The first operational high-vacuum CRTs did not appear until about 1931 from Zworykin RCA and Manfred Von Ardenne Germany, with suitable colour and spot size tubes appearing in 1934. I know the article did not state that TV-type CRT tubes were available but the inference could be deduced by a non-technical reader. That Zworykin of RCA had a complete all-electronic colour TV system is an example of journalistic license; the system of colour synthesis can hardly be called a complete colour TV system. A complete system must include capture, transmission, reception and display. Zworykin did not have such a complete system but just a basic patentable outline. Incidentally, Baird reportedly demonstrated and patented a working mechanical colour system in England during the late 1920s. Despite this rather long-winded critique, I found the article to be most informative and interesting, taking me back on a wonderful nostalgia trip to my early days with ATN7 Sydney during the 1960s and early 70s. Victor G. Barker, VK2BTV, Gorokan, NSW. Kevin Poulter comments: Regarding Baird transmitting across the Clyde (Scotland) I will talk to the elderly lady who told me her father helped Baird and see if any new light can be shown on the matter. Whilst she is elderly and not from a technical background, those were her very words. Regarding the Marconi 405-line system, it seems that one reference book shortened Marconi-EMI to Marconi. Unfortunately some textbooks do have errors. The amount of space available for the article also prevented going into the detail given by Mr Barker. Regarding CRT tubes, Mr Barker’s last sentence above says it all. We do not ask the wrong twist to be read into brief statements. I was incredibly impressed with the very early inventor’s creation and the similarity to much later TV tubes. Queries on digital camera articles In your March 2006 edition on page 11, it would have been good if there was a technical explanation given for the delay between “shutter” and capture. It seems strange that you can have an image on the electronic viewfinder but not be able to preserve that image at the instant the “shutter “ button is pressed . . . or is that viewfinder only a subset of the picture? In the same edition, on page 13, in the RGB, the B is meant to be Blue, not the Black as printed. In the April 2006 edition on page 30, presumably the quote from the Japanese camera technicians was an April Fool’s joke. Otherwise the statement undermines the author’s credibility and should have at least attracted an editorial comment. Such inaccurate statements may be acceptable in a camera magazine but not in your publication which always gives (errors excepted) credible information. In the April 2006 edition on page 35, a 70-210 acting as if it is 105-315 being “quite a long range“ zoom is not correct; they are both the same in zoom range (which is the ratio of the longest to the shortest focal lengths) – ie, they are both 3X. Admittedly a significantly greater “telephoto” is achieved at 315mm equivalent. Graham Goeby, via email. Kevin Poulter comments: The viewfinder image is not the actual image that is recorded, even in cameras with an electronic viewfinder. It is just a ‘thumbnail’ rendition. A camera may siliconchip.com.au have this thumbnail or low-res image already in the viewfinder but digital cameras have a lag, or processing time, between the press of a shutter and actual exposure. This lag is the same (and therefore independent of) any shutter-speed. Previously, lag was long enough to seriously miss action photographs (and still is, on economy models) but has now been reduced to acceptable levels in quality digital cameras. There are three lags, which I will generically call: (1) Booting on (at switch on); (2) Shutter to exposure lag; and (3) Processing and writing lag (titled “latent period” by some). Lag, burst-rate and latent time are absolutely vital to sports and nature photographers. The author has two books by a world-renowned London-based digital photography lecturer that doesn’t even mention “lag time” once. Regardless, nothing is more important to an action photographer. Latent time – the buffer memory capacity plus the write speed of cards – is another delay. It’s not widely known but like computer hard-drives, digital cards have a write speed, especially as many are micro hard-drives. When more than one image is taken in close or very close succession, the buffer memory stores the image, to give the card time to process it and write it to the card. Processing includes altering the captured image to the owner-selected settings on the camera, like contrast, colour balance, colour saturation and sharpness. The buffer-memory ensures more photographs can then be taken, even though the last images are still being processed. It’s still easy to reach the limit of this capacity, after a small number of high-resolution photographs in quick succession. In most instances, the more expensive the camera, the better this performance is. Unless you need “motor-drive” performance, this delay is not anywhere near as critical as the shutter lag-time. When choosing a camera, it’s often best to download the instruction manual first and read it to see if it is right for you. Sometimes the best place to start reading any instruction manual is the troubleshooting section, as occasionally inherent flaws are admitted. Do not accept “burst rate” figures that refer to low-resolution file sizes, if you do not intend to use the camera in low resolution. Some cameras specify, say, 30 frames with no write-time delay at low resolution but that’s deceptive if all the images are almost ‘thumb-nail’ low resolution and therefore too small for printing. RGB is Red, Green and Blue, as correctly mentioned earlier in the article. The quote from the Japanese camera technician was no joke. He was clearly referring to the digital camera computer’s inability to handle files other than those it was designed for, like any other computer. And just like any other computer, it could cause a serious or terminal crash. It’s even inadvisable to load jpg images and cards formatted from other cameras. In fact, digital camera instruction manuals state third-party cards (ie, cards not the camera’s brand), are formatted by the camera before use. “Quite a long range” (as opposed to “quite a long zoom siliconchip.com.au range”) referred to the degree of magnification of distant objects, the same as “range” refers to distance in other optics, like a weapon’s sights. I believe these informal (albeit ambiguous) generic references have been used by camera enthusiasts for more than 40 years, referring to a telephoto lens as a long-range zoom and a wide-angle zoom lens as a wide-range zoom. Certainly the magnification of the effective focal length of lenses due to the smaller size of digital sensors is a bonus. Lower shutter-speeds can be used before camerashake blur of images occurs. Also, less expensive optic technology is needed to create a long (telephoto) zoom. The only time when this effective magnification is not a bonus is when a very wide-angle lens is required. Then a super-wide, very expensive optic is needed, unless a composite panorama is taken. The author only has lenses to the equivalent of 28mm, preferring to save $1000 or much more on very wide-angle lenses. Instead, a very wide-angle photograph is achieved by taking two, or even three wide-angle images and joining them into a super-wide panorama. Often the result is clearer and less distorted as well. The only downside – hours or even days of creative computer time are expended in Photoshop. The finishing touch – the ultimate final tweak – is deciding if any distortion to the final photograph will make it look even more like a true wide-angle photograph. Normally a slight SC stretch of the width will be appropriate. August 2006 7 HOME THEATRE VIDEO PROJEC Are you about to buy a home theatre setup? For the very best home theatre experience you need a high-definition projector. This survey will help you make an intelligent selection, enabling you discriminate between high definition, standard definition and data projectors and also gain an overview of the different projector types. By Barrie Smith H ome theatre should be exactly that: a room in your home that will replicate as closely as possible the real cinema experience. That experience can only be created with a projector and a big screen … preferably wall size. While LCD and plasma TV manufacturers are busy expanding the screen dimensions of these display devices — Samsung has got to a 102-inch (2.6 metres diagonal) plasma screen — these massive flat screen TVs are not a realistic solution to your needs for a home cinema. They do have drawbacks, such as the amount of heat generated by such a display, the weight of a 4-metre screen, the continuing problem with plasma burn-in … and don’t even think about the price! You may find you’ll have to sell the house to buy one! Talk cinema at Hoyts or in the home – and you’re talking projection; digital video projection that can take a digital signal from the nearest transmitter or DVD player, plus multi-channel surround sound. There is a big selection of projectors to consider – there are around 30 different brands of video projector on the Australian market. Some makers have one model in their range, others three or more. Investment Let’s lay out the territory. For a home cinema, you need a suitable room, a projector, the signal source (broadcast programming in analog or digital, SD or HD or a DVD player) 8 Silicon Chip Photo: Len Wallis Audio and a multi-channel audio system. Oh, you may think it advisable to invest in a ‘proper’ screen, with a suitably reflective surface and matte black surrounds. Then again, many people make do with a white painted wall. The selected site for Cinema Chez Nous will ideally be a largish room that can be easily darkened. A room that is beset by high ambient light levels is patently unsuitable: even high output projectors don’t look good in a bright room. Anything up to eight speakers will have to be accommodated in the scheme. A room with ‘bright’ acoustics from parallel, painted walls is far from ideal. Two theatres in my local multiplex could win an Oscar for poor sound – due to precisely this reason – so at least, in this respect, you have the opportunity to outclass your local picture palace. You will also need somewhere to mount the projector, such as a floor-mounted console or an in-ceiling installation. And seating: preferably comfortable armchairs … don’t forget King Kong lasted two hours and fifty minutes – and the DVD version of Gone With the Wind lasts an excruciating 238 minutes (near enough to four hours!). In the above plan I’m talking about a front projection set up. If you want to get really classy and hide the projector behind the screen, letting it throw the image in a back projection mode, most projectors can provide for the picture to be laterally flipped to enable this set-up. But then you need to allow for the extra real estate behind the screen! siliconchip.com.au CTOR SURVEY There’s a lot more to all of this but you get the general idea. Possibly the most crucial decision you must make before even deciding on the make or model of projector is to get your head around the technology used to bring the picture to the screen. resulting in colours that slowly shift to red or blue. DLP (Digital Light Processing) DLP projectors (also known as DMD or Digital Micromirror Device) use a panel composed of hundreds of thousands Liquid Crystal Display (LCD) LCD projectors can use a single panel or three separate LCD panels. With the latter, each panel is devoted to one of the red, green and blue signals fed into the projector. As light passes through the LCD panels, individual pixels are opened or closed, to allow light to pass or be blocked. This action produces the on-screen image. To separate the individual pixels, LCD projectors use a microfine grid to prevent one pixel’s light from affecting the neighbouring pixel. Although the grid is essential to maintain picture quality it also entails some loss of light, which is partially absorbed as it impacts on the liquid crystal layer. Some projectors use a micro lens array in front of the grid to concentrate and direct the incoming light. Most reviewers feel that LCD produces a sharper image than the DLP approach (below) and delivers more on-screen light output, using the same wattage lamp. LCD’s failings (in some models) are: the “screen door effect” caused by the inter-pixel spaces; lack of a decent black and appreciable contrast and dead pixels may mar the picture. LCD panels are known to slowly decay over time, siliconchip.com.au With 3LCD-based projectors, the white light from the lamp is separated into the three primary colours by the dichroic mirror/filter. Each beam of light then passes through its appropriate colour LCD panel for processing. Each individual pixel on the LCD panel will turn on or off (partially or totally) to create the desired brightness and colours needed on screen. August 2006 9 Each Digital Micromirror Device (DMD) chip is made up of millions of tiny mirrors. Each mirror is dedicated to an on-screen pixel. White light from the lamp goes through the red, green and blue (and in some cases white) colour wheel. As the coloured light passes into the DMD, the specific mirror will reflect it by tilting at varying angles at a very fast speed. Like LCD projectors, in the LCOS system white light from the lamp is separated into the three primaries by the dichroic mirror/filter. The coloured light rays then travel to the liquid crystal panels, which reflect the appropriate colors and brightness on the screen (in similar fashion to the DMD chip). of moving micro mirrors, controlled by underlying semiconductor electronics and a spatial light modulator. When fed a digital video signal a DLP chip’s mirrors can reflect a completely digital image onto the screen. The DLP panel’s micro mirrors are mounted on tiny hinges so they can tilt either towards or away from the light source, creating either a light or dark pixel on the screen. This happens several thousand times a second. The white light generated by the lamp in a DLP projection system passes through a colour wheel as it travels to the surface of the panel. The colour wheel filters the light into red, green and blue; mixtures of these primaries can produce all the intermediate hues, such as brown, purple, etc. High-end DLP projectors use a 3-chip configuration with no colour wheel. Consumer projectors use a single chip DLP panel and a colour wheel, having anything up to eight segments, to avoid the so-called “rainbow effect”. This is more visible to some people than others and may be seen as a momentary multi-colour shimmer due to the fact that not all the colours in an image are projected at the same time. DLP projectors can be smaller than LCD models and produce less heat. They suffer less from the “screen door effect” than LCD models because the control circuitry surrounding each mirror isn’t as large. DLP technology may not be quite as colour-accurate but the colours will not shift over the course of its lifespan. The Interface n quality, the highest on-scree If you’re aiming for jector is pro d signal source an the interface between important. mposite, in this listing have co Virtually all the units ks these lin o inputs. Being analog broadcomponent and S-vide n itio fin stard with a High De liver de really don’t cut the mu n ca ion ect nn component co r. cast signal, however a playe s from a decent DVD very satisfactory result l transfer ita dig the s wa e) ac erf DVI (Digital Video Int high-end ra ult HDTV and other HDMI. method of choice for by d de rse pe now being su video displays but is , al) DVI-A of DVI: DVI-D (digit There are three types alog]). an tegrated [digital and (analog), and DVI-I (in e) is the ac erf Int n Multimedia HDMI (High Definitio ressed mp co un ng rti rrier, transpo new digital signal ca y the displa device channel audio data to 10 S ilicon Chip d multivideo an Liquid Crystal on Silicon (LCOS) LCOS is a new display technology that shows great promise, possibly able to yield even finer resolution and clarity than LCD or DLP but so far, there are very few LCOS models available. Philips, Intel and Toshiba have all explored LCOS and “walked away”, failing to see a commercial return on the development costs. At this stage, LCOS is more expensive than LCD or DLP. LCD uses transmissive technology; DLP uses a reflective method. Consider LCOS as a hybrid of LCD and DLP. It is a reflective technology that uses liquid crystals instead of individual mirrors. In LCOS, liquid crystals are applied to a reflective mirror substrate. As the liquid crystals open and close, the light is either reflected from the mirror below or MI to DVI . It is possible to get HD through a single cable I, should , going from HDMI to DV cables, so compatibility a DVI ect nn wever, you cannot co not be a problem. Ho with HDMI input. source to a projector the input listed here will handle s tor jec While all pro n actually n image signal, few ca of a true High Definitio . A model d pixels on the screen put all those lines an e downag im n 20 pixels on-scree that delivers a 1280x7 e result Th e. ag im el 20x1080 pix samples the original 19 will be t t the absolute best tha they is pretty good but is no en wh rs y or HD DVD playe obtainable with Blu-ra are finally released. s than with an output of les Note that any projector fin de ition. ot be regarded as high 1280 x 720 pixels cann n), 1080i sca e 720p (progressiv An HDTV signal is in the t. ma (progressive) for (interlaced) or 1080p siliconchip.com.au GREAT VIEWING ANYWHERE ITALIAN DESIGNED & BUILT SUPPORT SOLUTIONS OMB Support Solutions For LCD & Plasma Monitors, TV’s, VCR’s, Decoders, Speakers, Microwaves and More... INSTALLERS / DEALERS FREE Full Colour Catalogue Available Contact Us Today! siliconchip.com.au AUSTRALIAN DISTRIBUTOR: WES AUSTRALASIA, 138 Liverpool Road Ashfield, NSW 2131 Tel. 02 9716 0741 Fax. 02 9798 0017 Email. wes<at>wes.net.au August 2006 11 UHP lamps – the heart of modern video projectors While the technology behind the LCD, LCOS and DLP panels used in modern video projectors is impressive, all that would count for nothing without the UHP lamp which provides the very high light output to drive them. UHP stands for “ultra high performance” or “ultra high pressure”, depending on which literature you are reading. UHP lamps are very expensive to replace, typically $500 to $700, and their life is typically around 3000 hours. That very high cost is much greater than the lamps used in 35mm slide projectors and the difference is due to the complex technology used in UHP lamps. A UHP lamp is a high-pressure mercury discharge lamp. The mercury vapour arc is typically only 1mm long, established between tiny tungsten electrodes. When the arc is up to full temperature (at just a little less than the melting point of tungsten – 3000° K), the mercury vapour pressure is between 200 and 290 bar (3000 to 4300 psi!). The very high pressure is used to obtain a flatter spectral output from the discharge but even so, filters Replacing the ~$700 UHP lamp in a video projector is not a job for the faint-hearted – in fact, it should only be attempted by professionals with access to all the right gear and software. 12 Silicon Chip Extra close-up of the business end of the Sony UHP lamp, clearly showing the spiral ignition coil wrapped around the “burner”. You can also see the tiny arc gap in this picture. are required to provide a white light output. The entire lamp (the burner) itself is typically less than 50mm long and is mounted longitudinally in a parabolic reflector with the arc situated at the focus and usually with a spiral electrode around one half, for igntion. The lamp requires a high voltage to ignite it (up to 5kV) but when established, the arc runs at around 65V and 2A for a 120W lamp. Hence the lamp also requires complex electronics to ignite and drive it, similar to that used for high-intensity gas discharge lamps in up-market cars. Lamps should only be replaced by qualified technicians with access to the projector’s internal software to reset the timer to zero. Pictured at the top of this page is a selection of projector lamp assemblies from Sony, Panasonic and Philips. This shows a selection of UHP lamp burners rated at 100W, 150W and 250W. Notice the very small gap between the tungsten electrodes. siliconchip.com.au blocked. This modulates the light and creates the image. LCOS-based projectors usually use three LCOS chips, for the red, green and blue image data. Both LCOS and LCD projectors deliver red, green, and blue light to the screen simultaneously, leading to a more colour-saturated picture than straight DLP. LCOS advantages include: inherent high resolution; minimal inter-pixel space which delivers a smoother and more natural picture. Disadvantages are: low contrast in some models, limited lamp life and more expensive lamp cost. Canon has spent hugely getting LCOS into shape. They did the same thing with CMOS sensors for digital still cameras and were so successful they managed to encourage other companies like Sony and Nikon to follow. But LCOS is also a fickle technology, which is why InFocus, NEC, Sony and the other big guys aren’t even dealing with it. Bounce too much light off an LCOS chip and the image contrast ratio goes kaput. Ratchet down the lamp brightness to the point at which contrast is good and the image will be too dim for viewing in large areas such as conference rooms. In Canon’s approach, the light is allowed to pass through the projector’s polarising beam splitter to bounce off LCOS chips in parallel waves to maximise contrast, and in vertical/angled waves to maximise brightness. The system handles the projector control light in horizontal and vertical directions independently; something never before accomplished with an LCOS projector, says Canon. Usually, to get 2500 lumens using LCOS technology, a projection lamp must be larger and more powerful than those used to power equally bright LCD or DLP models. But Canon’s system allows for the use of a smaller lamp and smaller components, so making the projector more portable. The future of LCOS is still debatable but it is one to watch. JVC’s D-ILA Digital Direct Drive Image Light Amplifier (D-ILA) Be square-on can re-centre the screen form of keystone correction that ing up sett in s blem pro ious obv the ed er digital or optical corOnce you’ve solv image. This will consist of eith , killing the ling cab as h suc ters mat ma, your home cine rection. you next face the major LCD/DLP/etc image room’s ambient light and so on, With digital correction, the s term in ure pict n cree on-s the pixellated image challenge of optimising the is corrected by a reshaping of ess. before the picture aren squ ess of rectilinearity or to produce on-screen squaren screen, you the at ed aim tly rrec inco is or If a project reaches the lens. stone, both lateral and al lens is shifted to engage with the problems of key With optical correction, the actu e projectors this can vertical. square up the final image. In som hallthe is ure pict en scre idal ressive control of ezo imp An off-square, trap be very sophisticated and afford em. syst tre thea e hom up set rly mark of a poo the screen image. e – to begin with – to optical correction In general terms, it’s best practic Both work very well but I feel that ned alig e sibl pos as ely clos as of control available. position the projector lens has the edge, due to the amount reasons are e ther find then You imum distortion as tre. min with the screen cen Optical correction also delivers furniture in ble: ieva ach ly rare the screen image. is t tre spo cen to mum why this opti the lens is actually shifted etc. to distortion but also the way, inconvenient location Digital correction can not only lead jecpro the n itio pos y arel squ Also take great care to introduce artefacts. surface so that you get ral and vertical keytor’s lens parallel to the screen A projector which offers both late . tion ge. solu ima a rectilinear stone correction is the best market have some the on ors ject pro all lly, nkfu Tha siliconchip.com.au August 2006 13 “MERLIN” Practical and Versatile Mini Broadcast Audio Mixer natural look of DLP projection. Technology aside, the key to a satisfactory viewer experience is the quality of the screen material used to display the picture and the ambient light environment of the home cinema… this is not to forget the quality of the source programming. Scanning method Safe External Switchmode Power Supply Broadcast Quality with Operational Features and Technical Performance identical to full sized Radio Station Mixing Panels Permanent Installation is not required, the “Merlin” is as easy as a Stereo System to “Set Up”,all connections via Plugs and Sockets The “Merlin” originally designed for Media Training use in High Schools and Colleges is a remarkably versatile Audio Mixer Applications: Media Training - Basic Audio Production - News Room Mixer - Outside Broadcasts - Radio Program Pre Recording On-Air Mixer in small Radio Stations - “Disco Mixer” The “Merlin” is an Affordable Professional Audio Product Buy one for your School, College, Community Radio Station, Ethnic Radio Broadcast Association or for yourself For Details and Price, please contact us at ELAN Phone 08 9277 3500 AUDIO Fax 08 9478 2266 2 Steel Court. South Guildford email sales<at>elan.com.au www.elan.com.au Western Australia 6055 technology uses the LCOS principle and was developed by JVC. The chip is a CMOS design which has the benefit of placing the matrix addressing switches and electronics right behind (not between) the light-modulating liquid crystal layer. The result is a 93% fill factor and virtual elimination of the “screen door effect” so that that images can be as smooth and natural as film with fine reproduction of details in the original image. Other pluses are high brightness, high resolution, high contrast and analog gradation. Sony’s SXRD This design appears to be similar to that of LCOS displays but with some proprietary refinements. SXRD, like LCOS, is reflective; light passes through a liquid crystal layer, which controls the light from each pixel, then is reflected back out. In the QUALIA projector, three SXRD devices (red, green, blue) can fit on a chip measuring just 0.78 inch diagonally. This radically increases the amount of light that can reach the screen and reduces the “screen door” effect. Other benefits are rapid response time with none of the image lag that afflicts most LCD devices. A contrast ratio of 3000:1 is claimed for the SXRD panel itself. The pure Xenon lamp has a more even color spectrum than the UHP lamps used in most digital home theatre projectors. Look’n’feel Many people find the choice of a projection display technology (LCD, DLP or LCOS) becomes a subjective chore. Some prefer the sharpness of the LCD image or the more 14 Silicon Chip Progressive or interlaced scanning? We’ve all grown up with interlaced scanning in our home TV sets and it was only when computers, using progressive scan, started to proliferate in the domestic scene that most of us became aware that there was another way to ‘paint’ an electronic picture. Interlaced scanning was initially a means to rapidly get a picture onto the phosphor-coated screen of cathode ray tubes; the benefit was less transmission bandwidth. On your television set, half the lines (called a field) are displayed at 50 times a second (Hertz) and then the other half are woven in at 50 times per second; the eye’s persistence of vision enables the two halves of the raster to knit a complete, flickerless video frame. In PAL we have two interlaced 50Hz displays or 25 complete pictures in each second. NTSC uses a 60Hz system, delivering 30 complete interlaced pictures every second. At one stage quite a few manufacturers marketed 100Hz TV sets, using internal digital frame stores to double up the 50Hz interlace halves and deliver a faux-50Hz display. This seems to have lost market appeal in recent times. Progressive scan in the home TV appeared when high quality sports broadcasting came into its own. With progressive scan you get 50 complete pictures every second. LCD and plasma monitors typically only display video signals in a progressive scan format. LCD monitors do not use phosphors and are not susceptible to screen burn. Ghosts Fastidious viewers soon notice the response lag of LCD systems — both with flat pan el teles and projectors. A fast response time is the tim e in milliseconds it takes for the LCD cells to change from active to inactive and back again. A quicker respons e time gives fast and more accurate on screen action. In subject matter such as sports programming and video games it can be annoying to find that the ball, cursor or similar will ‘ghost’ or ‘sub marine’ across the screen, without showing a smo oth transition from A to B. If you like watching ultra-rapid action in your movies, or you’ve hooked up you r PlayStation to the projector to play games, you sho uld look for one with a response time of less than 25m s. ViewSonic has developed LCD technology with a rated response time of just one millisecond. Using a ViewSonic OverDrive chip, a plu g-in replacement for a microprocessor designed to speed up the PC in which it is used, it seems set to appear in computer displays first. No doubt the high-speed displays will also be attractive to other digital program ming viewers; the serious gaming market is one whe re players will spend extra dollars to achieve high perf ormance. siliconchip.com.au what’s life? ...if it’s all work and no Home Entertainment C R E A T I O N Home Theatre I N N O V A T I O N Home Automation I N S T A L L A T I O N I N S P I R A T I O N 64 Burns Bay Road Lane Cove NSW 2066 • Ph (02) 9427 6755 Fx (02) 9427 2490 • sales<at>lenwallisaudio.com.au www.lenwallisaudio.com.au Admark 14-A29SilChp siliconchip.com.au August 2006 15 The Listing Some manufacturers market projectors intended for data display as well as home theatre use. Data projectors typically have small displays, usually 800x600 pixels; far from HD quality! Only one is included in the listing. As best as can be determined, the following listing covers the models ideally suited for home theatre, which also usually possess all of the appropriate video interfaces. All projectors will accept signals in the PAL/NTSC/SECAM standard as well as those in Standard and High Definition. Considerable care was taken in the assembly of this information, quite often obtained with great difficulty. If there is the odd discrepancy, you may have to lay it at the feet of the individual company and its negligence in assuring that the correct info was supplied or placed on its Web site. We surely tried! So let’s get on with the listing. . . ACER BARCO ACER PH110 CineVERSUM 60 (www.acer.com.au) Display: DLP. Native Aspect Ratio/ Resolution: 16:9/854x480. Brightness: 1100 ANSI Lumens. Contrast Ratio: 2000:1. Lens: f2.5 to 2.7/20.2-24.2 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite and component video, HDTV. Price: $1999. Acer has five other models, suitable for data and video display; prices range from $1299 to $4199. ACTION! (www.ambertech.com.au) ACTION! Model One Mark II (and Mark III) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 3000:1 (4000:1). Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $10,999 ($21,750). ACTION! Model Two Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 4000:1. Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $9999. ACTION! Model Three Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 2500 ANSI Lumens. Contrast Ratio: 7500:1. Lenses: Optional range. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $42,000. 16 Silicon Chip (www.pioneeraus.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: 900 ANSI Lumens. Contrast Ratio: 2000:1. Lens: two 1.3x zooms. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $7,999. CineVERSUM 70-Ultra Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 2700:1. Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $10,999. CineVERSUM 80 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 3000:1. Lens: range of lenses. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $19,995. CineVERSUM 110 Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 3000 ANSI Lumens. Contrast Ratio: 2500:1. Lens: range of lenses. Audio/Video Interface: S-Video, composite & component video, SDI (optional), DVI. Price: $44,999. CineVERSUM 120 Master Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 3000 ANSI Lumens. Contrast Ratio: 2500:1. Lens: range of lenses. Audio/Video Interface: S-Video, composite & component video, DVI, SDI (optional). Price: $44,999. siliconchip.com.au BENQ CINEO BENQ W100 CINEO1 (www.benq.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/853x480. Brightness: 1100 ANSI Lumens. Contrast Ratio: 2500:1. Lens: f2.6-2.77/20.4-23.5mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $1499. BENQ PE7700 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1100 ANSI Lumens. Contrast Ratio: 2500:1. Lens: 1.37x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $2799. BENQ PE8720 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 10,000:1. Lens: f2.4-2.8/32.1-43 mm; 1.35x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $9999. In this company’s range are six additional models, suited for office presentations. At 1.9 kg in weight, the PB2250 is a portable unit. The PB8260 offers a 3500 ANSI lumens output and wireless operation. (www.ambertech.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: NA. Contrast Ratio: 3000:1. Lens: 1.3x or 1.5x zoom. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $15,500. CINEO3 (two models) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 3500 ANSI Lumens. Contrast Ratio: 7500:1. Lens: Variable lenses. Audio/Video Interface: S-video, composite & component video, DVI-D. Price: $25,999 and 29,999. DELL (www.dell.com.au) 1100MP Display: DLP. Native Aspect Ratio/ Resolution: 4:3/800x600. Brightness: 1400 ANSI Lumens. Contrast Ratio: 2100:1. Lens: f2.5/28.8-34.5 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $1299. 2300MP (www.canon.com.au) Display: DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 2300 ANSI Lumens. Contrast Ratio: 2100:1. Lens: f2.4-2.7; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2199. CANON XEED SX50 3400MP Other Canon models, possibly more ideal as data projectors, include LV-7240, LV-7245, LV-S4, LV-X5. All of these are portable models and all use LCD panels. Of particular note is the LV-7565 — a “large audience” device, using an LCD panel with 1024x768 pixel resolution, a 4:3 aspect ratio and with a light output of 5100 ANSI Lumens in “brighter mode”. 5100MP CANON Display: LCOS. Native Aspect Ratio/ Resolution: 4:3/1400x1050. Brightness: 2500 ANSI Lumens. Contrast Ratio: 1000:1. Lens: f1.85-2.5/22.0-37.0 mm; 1.7x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $7689. siliconchip.com.au Display: DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 1500 ANSI Lumens. Contrast Ratio: 2100:1. Lens: f2.7-2.88/28.43-32.73 mm; 1.15:1x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2399. Display: DLP. Native Aspect Ratio/ Resolution: 4:3/1400x1050. Brightness: 3300 ANSI Lumens. Contrast Ratio: 2500:1. Lens: f2.6-2.87/39.1-46.92 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $4999. August 2006 17 EPSON HEWLETT-PACKARD EMP-TW20 mp3322 EMP-TWD1 DVD player/projector While not marketing its range as specifically for home theatre use, HP’s models are interesting nonetheless. (www.epson.com.au) Display: LCD. Native Aspect Ratio/ Resolution: 16:9/854 x 480. Brightness: 1200 ANSI Lumens. Contrast Ratio: 1000:1. Lens: f1.7-2.1/16.6 mm. Audio/Video Interface: S-Video, composite & component video. Price: $1699. Display: LCD. Native Aspect Ratio/ Resolution: 16:9/854 x 480. Brightness: 1200 ANSI Lumens. Contrast Ratio: 1000:1. Lens: f1.7-2.1/13.7-20.5 mm; 1.5x zoom. Audio/Video Interface: S-Video, composite video. Price: $2499. EMP-TW600 Display: LCD. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1600 ANSI Lumens. Contrast Ratio: 5000:1. Lens: f2.1-2.8/21.4-31.7 mm; 1.5x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $2999. At the time of this listing, Epson also had another 10 or so additional models in their range, most of which are intended for office use. An interesting and additional trio are described as multimedia projectors; an example is the EMP-9300, which has an ANSI output of 2500 Lumens; contrast range of 1100:1; 4:3 aspect ratio and 1400x1050 resolution. FUJITSU (www.fujitsugeneral.com.au) FUJITSU LPF-D711 Display: 3LCD. Native Aspect Ratio/ Resolution: 16:9/1920x1080. Brightness: 1200 ANSI Lumens. Contrast Ratio: 3300:1. Lens: f1.8-2.1; 1.7x zoom. Audio/Video Interface: DVI-D and (via supplied selector) S-Video, composite & component video, HDMI. Price: $39,999. LED light illuminasage a major change to It’s tiny but it may pre projectors. tion sources for video tor ($1799) FF1 Micro LED projec its e: on Toshiba has tor … and world’s first LED projec is claimed to be “the palm of a the lightest!” It fits in world’s smallest and resolution a s ha , battery powered le ab rge ha rec is , nd ha io. It comes d a 1500:1 contrast rat of 800x600 pixels an . with a fold-away screen the palm of etProjector also fits in ck Po D LE s hi’ bis tsu Mi 750 grams d un aro s erated, weigh your hand, is battery op 18 Silicon Chip (www.hp.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 2400 ANSI Lumens. Contrast Ratio: 2000:1. Lens: 1.2x zoom. Audio/Video Interface: composite & component video. Price: $3108. Two mobile models: HP mp2225 and mp3135 ($2499 and $3999). These weigh only 1.1 kg and 1.7 kg respectively. ANSI Lumens output: 1400/1800; Aspect ratio/resolution 4:3/1024x768; 1400/2000:1 contrast range; S-Video/composite & component video. Two conference models: HP xp7010 and xp7030 ($5000 and $6000). ANSI Lumens output: 2200/3300; Aspect ratio/resolution 4:3/1024x768; 800/1000:1 contrast range; NTSC/PAL/SECAM/HDTV; S-Video/composite & component video. Three ‘versatile’ models: vp6315, vp6325 ($1499, $2299). ANSI Lumens output: 1600/2000; Aspect ratio/resolution 4:3; Contrast range 2000/2500:1; S-Video & composite video. HITACHI (www.hitachi.com.au) PJ-TX200 Display: LCD. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1200 ANSI Lumens. Contrast Ratio: 7000:1. Lens: f1.8-2.4/20.0-31.9 mm; 1.6x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $3299. While not specifically described by Hitachi as home theatre projectors, another five models range in price from $2199 to $10,999 and offer a variety of performance specifications. Top of the range is the CP-SX1350W, delivering 3500 ANSI Lumens output; 1400x1050, 4:3 aspect ratio/resolution; 500:1 contrast ratio; PAL/NTSC/SECAM/ HDTV; S-Video, composite & component video. rce. The uential 3-LED light sou and is powered by a seq p operation g life, quick on-off lam benefits of LEDs are lon Mitsubishi e d and low cost. Th with no warm up perio 600 pixels 0x 80 tive resolution of has a DLP panel, a na US$799. and a 4:3 aspect ratio. using an msung’s Pocket Imager: Sa is nt tra Another en ms and gra 0 device weighs just 69 ntrast Ostar LED light, the co a d an ns of 420 ANSI Lume has a claimed output ratio of 1000:1. siliconchip.com.au INFOCUS JVC IN72 DLA-SX21EH (www.internationaldynamics.com.au) Display: DLP. Native Aspect Ratio/ Resolution: 16:9/854x480. Brightness: 900 ANSI Lumens. Contrast Ratio: 2000:1. Lens: f2.4-2.6/21.0-25.0 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $2699. IN74 Display: DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: 1000 ANSI Lumens. Contrast Ratio: 3000:1. Lens: f2.4-2.8/21-27 mm; 1.31x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $3499. IN76 Display: DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 3000:1. Lens: f2.4-2.8/21.0-27.0 mm; 1.31x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $5999. SP7205 Display: DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1100 ANSI Lumens. Contrast Ratio: 2200:1. Lens: f2.7-3.1; 1.31x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $7999. SP7210 Display: DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1100 ANSI Lumens. Contrast Ratio: 2800:1. Lens: f2.7-3.1; 1.31x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $10,999. SP777 Display: DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 2000 ANSI Lumens. Contrast Ratio: 5000:1. Lens: Various, ranging from 1.2x to 1.55x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $23,999. siliconchip.com.au (www.jvc-australia.com) Display: 3D-ILA. Native Aspect Ratio/ Resolution: 4:3/1400x1050. Brightness: 1500 ANSI Lumens. Contrast Ratio: 800:1. Lens: 1.3x zoom. Audio/Video Interface: Composite & component video. Price: $11,999. DLA-HX2E Display: 3D-ILA. Native Aspect Ratio/ Resolution: 16:9/1400x788. Brightness: Not specified. Contrast Ratio: 1500:1. Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $13,999. DLA-HD2KE Display: 3D-ILA. Native Aspect Ratio/ Resolution: 16:9/1920x1080. Brightness: Not specified. Contrast Ratio: 2000:1. Lens: 1.3x zoom. Audio/Video Interface: DVI-D, (S-Video, composite & component video, HDMI via additional video processor). Price: $29,999. DLA-HD10KSE Display: 3D-ILA. Native Aspect Ratio/ Resolution: 16:9/1920x1080. Brightness: Not specified. Contrast Ratio: 2500:1. Lens: 1.4 and 1.9x zooms available. Audio/Video Interface: DVI-D, (S-Video, composite & component video, HDMI via additional video processor). Price: $29,999. MARANTZ (www.qualifi.com.au) VP-12s4 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 700 ANSI Lumens. Contrast Ratio: 4500:1. Lens: 1.4 and 1.9x zooms available. Audio/Video Interface: S-Video, composite & component, HDMI, DVI (via adaptor). Price: $15,950. Brightness and Contr ast Generally speaking, the brighter (higher ANSI lumens output) the better. Sta rt at 1000 ANSI lumen s for most situations. A higher co ntrast in the on-scree n picture means more brilliant whites and deeper bla cks. Toolow-a-contrast pictur e is not worth watching . A figure of 1500:1 is a start; 20 00:1 is very watchable. August 2006 19 MITSUBISHI (www.mitsubishi-electric.com.au) HC900 OPTOMA (www.ambertech.com.au) DV-10 DVD player/projector Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: 1500 ANSI Lumens. Contrast Ratio: 4000:1. Lens: f2.4-2.6/23.0-27.6 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2999. Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/854x480. Brightness: 1000 ANSI Lumens. Contrast Ratio: 4000:1. Lens: 1.11x zoom. Audio/Video Interface: S-Video, composite video, optical audio. Price: $2499. HC3000 H-27 Display: 1DLP. Native Aspect Ratio/ Resolution: 15:9/1280x768. Brightness: 1000 ANSI Lumens. Contrast Ratio: 4000:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite video. Price: $3499. NEC (www.nec.com.au) HT410G Native Aspect Ratio/ Resolution: 16:9/854x480. Brightness: 1000 ANSI Lumens. Contrast Ratio: 1200:1. Lens: f2.0-2.48/19.5-23.0 mm; 1.18x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $1999. HT510G Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x526. Brightness: 1000 ANSI Lumens. Contrast Ratio: 1200:1. Lens: f2.0-2.48/19.5-23.0 mm; 1.18x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2999. CSMS ring ANSI method of measu One maker feels that the e. not sufficiently accurat projector brightness is laced maker Runco has rep High quality projector bert am t-L foo the fication with outthe ANSI-lumen speci ht lig the g rin ure for measu a em measurement proced Cin products. Adopting the y an put of its projection mp co ent System (CSMS) the d ite Standards Measurem su re mo re we SI standards feels that the earlier AN mens ys. It says the ANSI Lu pla dis eo to industrial vid charce the proper performan figure does not convey e. tur kes a good movie pic acteristics of what ma measusing the foot-Lambert “B More from Runco: y the to te ica un mm co we can be t urement specification gh mi e in his home theatre al loc customer that the imag his at e ple, than the imag ing 1.5x brighter, for exam try n tha ful ing ch more mean cinema, which is mu ll appear.” 1000 ANSI Lumens wi t gh bri to explain how runco.com/csms.html There’s more at www. 20 Silicon Chip Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/854x480. Brightness: 850 ANSI Lumens. Contrast Ratio: 2300:1. Lens: f2.6-2.8/22.34-26.8 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $1999. EP747 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024X768. Brightness: 3000 ANSI Lumens. Contrast Ratio: 2200:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $4299. HD-721 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x768. Brightness: 1300 ANSI Lumens. Contrast Ratio: 5000:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite and component video, HDMI, DVI-D. Price: $4750. H-78 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 3800:1. Lens: f2.4-2.69/28.3-38.2 mm; 1.35x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $11,999. PANASONIC (www.panasonic.com.au) PT-AE900 Display: 3LCD. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1100 ANSI Lumens. Contrast Ratio: 5500:1. Lens: f1.9-3.1/21.7-43.1/2x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $3299. The company has a wide range of data and commercial projectors. siliconchip.com.au RUNCO SANYO CL410 PLVZ4 (www.network-et.com) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: 800 ANSI Lumens. Contrast Ratio: 2500:1. 1.3x or 1.6x zoom. Audio/Video Interface: composite & component video, DVI. Price: $6999. CL420 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1200 ANSI Lumens. Contrast Ratio: 2800:1. Lens: Optional lenses. Audio/Video Interface: composite & component video, DVI. Price: $11,000. CL610 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1150 ANSI Lumens. Contrast Ratio: 2200:1. Lens: NA. Audio/Video Interface: composite & component video, HDMI. Price: $16,000. CL810 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1250 ANSI Lumens. Contrast Ratio: 3100:1. Lens: Optional lenses. Audio/Video Interface: composite & component video, HDMI, DVI. Price: $20,000. VX-1000d Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1500 ANSI Lumens. Contrast Ratio: 3300:1. Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $30,000. VX-2c Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 2500 ANSI Lumens. Contrast Ratio: 2800:1. Lens: Range of optional lenses. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $79,999. Runco has other models which begin at $53,000 and rise to $350,000. ANSI Lumens figures of 8000 are achieved with the latter. siliconchip.com.au (www.sanyo.com.au) Display: 3LCD. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 7000:1. Lens: 2x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $3999. PLV80 Display: 3LCD. Native Aspect Ratio/ Resolution: 16:9/1366x768. Brightness: 3000 ANSI Lumens. Contrast Ratio: 1000:1. Lens: f1.8-2.1/48.4-62.8 mm; 1.3x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $10,999. SHARP (www.sharp.net.au) PGMB60X (and PGMB70X) Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 2400 ANSI Lumens (PGMB70X – 3000). Contrast Ratio: 1200:1 (PGMB70X – 2000:1). Lens: 1.5x zoom. Audio/Video Interface: S-Video, composite. Price: $4299 (PGMB70X – $4999). XVZ2000 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1200 ANSI Lumens. Contrast Ratio: 2500:1. Lens: 1.5x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $5499. XVZ1200 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 900 ANSI Lumens. Contrast Ratio: 5500:1. Lens: 1.35x zoom. Audio/Video Interface: S-Video, composite & component video, DVI. Price: $10,999. This company serves the market well with alternative models, configured as portable projectors and for data projection. August 2006 21 SIM2 SONY DOMINO 30H VPL-HS60 (www.audioproducts.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: NA. Contrast Ratio: 2800:1. Lens: 1.3x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $9999. HT280 (www.sony.com.au) Display: 3LCD. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1200 ANSI Lumens. Contrast Ratio: 10,000:1. Lens: 1.6x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $3499. VPL-VW100 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: NA. Contrast Ratio: 2300:1. Lens: 1.4x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $8999. Display: 3SXRD. Native Aspect Ratio/ Resolution: 16:9/1920x1080. Brightness: 800 ANSI Lumens. Contrast Ratio: 15,000:1. Lens: 1.8x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $14,999. HT300E QUALIA 004 Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: NA. Contrast Ratio: 3500:1. Lens: 1.4x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $14,999. C3X Lite Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: NA. Contrast Ratio: 6500:1. Lens: optional 1.4x or 2.3x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $24,999. C3X Display: 3DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 2500 ANSI Lumens. Contrast Ratio: 6500:1. Lens: optional 1.4x or 2.3x zoom. Audio/Video Interface: HDMI, S-Video, composite & component video. Price: $29,999. Wide or Tele one probnnected with the keyst A factor not directly co difficult in lp he e. You may need large lem is screen image siz too or big too is final picture situations where the with the fitted lens. fashion to ses operate in similar Navitar conversion len normal the of nt ras; fixed to the fro y can those on digital came the n, ose ch l de nding on mo need zoom lens, and depe No . x or narrow it by 0.65x widen the image by 1.5 . to re-site the projector .com.au) nology: (www.ambertech Through Amber Tech 22 Silicon Chip Display: 3SXRD. Native Aspect Ratio/ Resolution: 16:9/1920x1080. Brightness: 1600 ANSI Lumens. Contrast Ratio: 15,000:1. Lens: Interchangeable range. Audio/Video Interface: S-Video, composite & component video, DVI-D, HDMI. Price: $POA. TOSHIBA (www.pioneeraus.com.au) P8 Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 1500 ANSI Lumens. Contrast Ratio: 2100:1. Lens: f2.0-2.88/28.43-32.73mm; 1.2x zoom. Audio/Video Interface: S-Video, composite video. Price: $3299. S25 Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 1800 ANSI Lumens. Contrast Ratio: 2000:1. Lens: f2.0-2.2/18.82-21.84 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $1999. MT700 Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 1000 ANSI Lumens. Contrast Ratio: 2500:1. Lens: f2.0-2.2/18.82-21.84 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI. Price: $4999. siliconchip.com.au VIEWSONIC YAMAHA PJ256D DPX-530S (www.viewsonic.com.au) (www.yamahamusic.com.au) Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 1600 ANSI Lumens. Contrast Ratio: 2000:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2699. Display: 1DLP. Native Aspect Ratio/ Resolution: 16:9/1024x576. Brightness: 1500 ANSI Lumens. Contrast Ratio: 4000:1. Lens: f2.72.6/23-27.6 mm; 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $4999. PJ755D DPX-1300S Display: 1DLP. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 2800 ANSI Lumens. Contrast Ratio: 2000:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $3099. PJ1172 Display: 3LCD. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 4500 ANSI Lumens. Contrast Ratio: 800:1. Lens: 1.5x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $6999. PJ656 Display: 3LCD. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 2100 ANSI Lumens. Contrast Ratio: 400:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite & component video. Price: $2499. PJ862 Display: 1LCD. Native Aspect Ratio/ Resolution: 4:3/1024x768. Brightness: 3100 ANSI Lumens. Contrast Ratio: 400:1. Lens: 1.2x zoom. Audio/Video Interface: S-Video, composite & component video, DVI-D. Price: $3999. Lamp Life mes as and have a life someti Lamps are expensive when ts en . Budget for replacem 2000 short as only 2000 hours y: wa s thi tor. Figure it out re mo you first buy the projec or 00 10 of ng to the viewi me co hours lamp life equates ll sti u yo see l u’l ths and yo movies but do the ma of cinema-going. st co the n tha out better ments; ened in warm environ ort Lamp life will be sh p has lam the … ns screening sessio another factor is long the projecd make sure you clean no chance to cool. An an economy . Many projectors have tor’s air filter regularly longing its pro p is under-run, so mode, in which the lam e. tur pic r ghtly dimme life but delivering a sli siliconchip.com.au Display: 1 DLP. Native Aspect Ratio/ Resolution: 16:9/1280x720. Brightness: 800 ANSI Lumens. Contrast Ratio: 5000:1. Lens: f2.7-5.0/ 24.3–38.9 mm; 1.6x zoom. Audio/Video Interface: S-Video, composite & component video, HDMI, DVI. Price: $16,999. Useful Web Sites An excellent source of varied information can be found at www.proje ctorcentral.com and www.bigscreenforums.com … in trawling the latter, take some of the comments with a grain of salt. More info on home the atre can be found at ho metheater.about.com (note the US spelling – “thea ter”.) Another useful site is www.ausmedia.com. au … home of retailer AIM Digital Imaging. Revie ws and explanatory data galor e. Similarly, www.dtvfor um.info is a very activ e discussion site. There is an excellen t glossary on Toshiba ’s Web site: www.isd.toshiba .com.au/projectors/pr ojectors/ service-glossary.shtm l … although it omits such subjects as HDMI, DVD-I and S-Video. Another can be found at www.hdtvinfoport. HDTV-Glossary.html com/ Great tutorials are fou nd on www.projectorp eople. com/tutorials Footnote: If you need to search for info on video projec tors, as I have, I must wish you the Best of British … some major makers’ Web sites are of little help, with som e superseded models still listed and some of the specs just plain wrong, mixed up as they are with specs from mode ls intended for other markets. As paying customers, we deserve better. SC August 2006 23 Television’s Golden Age Part 3 – By Kevin Poulter With next month marking a half century of television in Australia, this third and final installment in our unashamedly nostalgic series looks at what, to many, is regarded as the Golden Age of TV: its first twenty-five years. T elevision, like radio before, became the centre of household entertainment, values and enhanced education. Essential to many, television created employment, with a host of manufacturing, service, finance, retail and related businesses. The all-important ingredient was successful shows, as this led to more television receivers purchased, enabling growth in all areas. “In Melbourne Tonight”, hosted by Graham Kennedy, began in 1957, its success relying on slapstick comedy and light entertainment format. To the shock and dismay of advertisers, Graham soon lampooned their products. After initial complaints, advertisers were stunned to see their sales – and profits – growing as a result. 24 Silicon Chip Most drama was American, with a smattering of British content, so nothing has changed. Teenage programs were also popular, like Brian Henderson’s Bandstand on Sydney’s TCN9, Mickey Mouse Club, Brian Naylor’s Swallow Junior and the ABC’s Six O’Clock Rock, hosted by Johnny O’Keefe. This Day Tonight commenced on the ABC in 1967, soon reaching top popularity. TDT was initially flown all over Australia from its Sydney base, for telecast by ABC channels in other states. By 1969, television reached 95% of Australia’s population, with 45 commercial and 39 national stations keeping our nation entertained. Per capita, city stations provided more TV channels siliconchip.com.au than in USA or Europe. 81% of homes had a television set. Nearly all drama on Australian TV was produced overseas – a massive 97% – so rules were changed, requiring stations to present Australian-produced drama programmes for at least two hours a month, in peak viewing, between 7pm to 9.30pm. Safe at any voltage? Right through the era, valves remained the dominant technology, with plastic cabinets and solid-state slow to take on. Technicians needed to learn about television, so schools were commenced at the Royal Melbourne Technical College (RMIT) in 1955 and the ABC Sydney training school in St Peter’s Church Hall, opposite their radio studios in Forbes Street. HMV’s Television service manual for their all-valve chassis type M2 offers an insight to the state of technology at the time. . .“The “BP Australia presents . . . PickABox, with Australia’s favourite compere, Bob high voltage of the picture tube anode (16,000 Dyer . . .” Bob (shown here with Dolly Dyer) was one of relatively few radio volts EHT) will give an unpleasant shock, but personalities who made a successful transition to the new medium, television! doesn’t supply enough current to give a fatal burn or shock. However, secondary human Shocking! reactions to otherwise harmless shocks have been known to cause injury”. In the 60s, RMIT’s television department had about 25 Further – “the picture tube is highly evacuated and if brobare Astor chassis for students to work on. After initially ken, it will violently expel glass fragments. When handling powering up the Astor to measure voltages, I suddenly rethe picture tube, always wear goggles.” ceived a karate blow to the back of the neck. Students were I never witnessed technicians wearing goggles but some known to perform occasional pranks but on looking around, ‘scientific minds’ threw a tube into the dump-master from nobody was close by. a building’s second story, authoritatively confirming that Lesson learnt – don’t wear the latest fashion tie with metal there is indeed an implosion on impact! highlight threads near a live set! Returning to the HMV M2, this receiver boasted a turret tuner for precise alignment of the oscillator on each channel, through the front, an overall frequency response within 6dB from DC up to 4.7MHz, DC coupling from the video detector to the picture tube – ensuring full black, instead of greys in the shadows and night scenes – time-gated AGC, to nearly eliminate impulse noise, like ‘aircraft flutter’, plus many more leading edge technologies. A hinged vertical chassis made servicing much easier. (see photo overleaf). The sound from early console sets with an eight or twelve-inch speaker was most impressive too, even by (especially by?) today’s standards. Proof of the design and build quality of the higher-priced early sets is some still work, or are capable of reception after their leaky capacitors are replaced. CRTs remain the best. Now, after fifty years as the only medium to present TV images, the cathode ray tube is on its way out, sorely missed by many professional video editors and graphic artists. Despite the huge size and ‘cartoon colour’ of plasma screens, video editing staff continue to use ageing CRTs, as they exhibit a more accurate picture. Sony manufactured their last CRT TV in 2005 and others are following suit, so soon there will be no choice. An Astor 1956 console, with 21-inch tube displaying children’s host, Happy Hammond. siliconchip.com.au A potted history From the fifties to the seventies, a vast range of new proAugust 2006 25 like a live broadcast of football, beamed from Geelong to Melbourne. Originally partners, ATN7 Sydney established a microwave link in 1957, connecting to GTV9 Melbourne. Five mountain-top microwave links were employed in an exercise called Operation Kangaroo. 1958 was an eventful year too, with “Leave it to Beaver” achieving the first registered TV audience of over one million viewers. TCN9’s “Brian Henderson’s Bandstand” commenced, a variety music program that launched the careers of many Australians during 14 years of broadcasting. This was the year TV WEEK magazine started annual TV awards. GTV9’s Graham Kennedy won the Gold Award (for most popular TV personality) and named the awards the Logies, after TV pioneer John Logie Baird. The first Logie awards were held in a hotel, not televised until 1965, though they were presented on IMT for a few years. Video recording – at a premium price. Sets like this HMV M2, featured a swing-out chassis, making servicing more accessible. grammes, stations and networks appeared, so only highlights are mentioned here. Links with extensive details are found in the references web page, shown at the end of this article. On March 31 to April 1, 1957, the first Telethon was broadcast, with Graham Kennedy, a young radio announcer, making his first appearance. Producer Norm Spencer is later titled the ‘King Maker’. Shortly after, “In Melbourne Tonight” commenced five nights a week in the “not for kiddies” time-slot of 9.45pm. IMT’s ninety minutes of live, slap-stick humour, singing and acts entertained till 1971. Stars were created, like Bert Newton, Philip Brady, Ernie Sigley and Denise Drysdale. Fifty years later, many of these stars continue broadcasting. Microwave transmission, still utilised for links, was available from the beginning, enabling line of sight transmissions, Video recorders were a must-have for television stations. Nearly three years after first broadcasting, GTV9 purchased their first video recorder, in 1959, for 35,000 pounds. Features like still-frame and slow-motion were not available, though later a PYE slow-motion adapter was added to Nine’s unit. (see photo) During 1960, HSV7 acquired an RCA videotape recorder for 45,000 pounds, including spare parts. The challenges for designing improved videotape recorders included creating new features and better quality, with less tape and equipment costs. A leading Ampex engineer was playing with his dog, twirling a spiral of toilet paper. Then an inspiration hit him – why not spin the video heads in an angled pattern? In 1978, one inch helical-scan reel-to-reel video recorders became available, offering shuttling and still-frame, but the sound plus picture was not as good as the quad-head system. Stations equipped with video recorders saved money by A Videotape department in 1967. In the early ‘60s, each machine cost as much as 45,000 pounds. 26 Silicon Chip siliconchip.com.au The videotape recorders of the 60s were good quality, but lacked still frame and slow motion. Later, PYE made an adapter for slow motion. recording over programmes again and again, until dropouts on the tapes were excessive. Then tapes were thrown out. So a combination of mainly live theatrical-style shows, lack of VCRs, re-using tapes, disposing of used tapes and no insight they were producing history, means very little local TV footage from the era remains. As we mentioned in the first part of this series, even the famous, grainy, Bruce Gyngell “Welcome to Television” snippet that “records” the commencement of TV in Australia is itself a fake, recreated for posterity quite some time after the original in 1956! Fortunately, though, over the years some dumped tapes and equipment were rescued by enthusiastic staff. Even though they risked the wrath of station management at the time, years later those same stations began to borrow collectors salvaged video cameos of the era. Equipment also met the dump-master and still does, with just a few saved for history and especially useful for dubbing old programmes to DVDs. a multi-way plug onto the remote lead and run a suitably socketed cable under the floorboards from their watching position to where the TV receiver sat, so as to avoid a cable cluttering the lounge room floor! One of the first cordless units was the Admiral ‘Son-R remote’, appearing around 1960. It was an utrasonic unit – infrared was many years away. Inside the remote control, two solid brass rods were held by taut wires and tuned to ultrasonic frequencies, about 40kHz and 41kHz, one controlling the tuner and one for volume. Pressing a black button connected to a strip of spring steel resulted in a ‘piano string striker’ effect. A microphone, discreetly built into the TV cabinet fed an amplifier/frequency splitter, connected to stepper-motors. The turret tuner had its usual mechanical indent for a positive stop. The Son-R unit was very rare but is another example of early technology that led to the remote controls we enjoy and expect today. Pass me the remote. Renewing old tubes Remote controls for TVs were uncommon and unwieldy, usually connected to the TV receiver via a long cord. It wasn’t uncommon for the more technically minded to fit Television picture tubes were very expensive, with early predictions of short picture-tube life. So refurbishing factories started to open. siliconchip.com.au August 2006 27 The Telecine department in TV stations was a busy vital area. Film was transferred to tape or broadcast. On the top right, an Astor table-top receiver is used as a monitor (this receiver was also used in many homes). In today’s ‘throw-away’ society, its hard to imagine these companies offered a total service – collection, delivery, payment for the faulty tube, refurbish – and still sold the rejuvenated tubes much cheaper than new, including a 12 month warranty! Rebuilding of the picture tubes commenced with inspection under ultraviolet light and any scratches on the tube face removed. Then cleaning and washing in a chemical solution followed. Next, a hot wire was placed around the neck to crack it. This causes a gradual rush of air into the tube, then the gun fell off. After mounting the tube on a lathe, the glass neck was cut to within one inch of the flare of the cone. A new gun was then affixed to the tube, by heating, using air and gas jets. Finally, the gun was placed in a 725°F oven for two hours, while pumps evacuated the tube. The coax cable A television breakthrough, the coaxial cable was laid in 1960, between Sydney and Melbourne. During the same year, Sir Frank Packer of Consolidated Press purchased GTV9 for three million pounds. Toward the end of October 1960, a Marconi colour television system was demonstrated in various venues around Australia, including at the Royal Melbourne Hospital. Australian television receiver licences in 1961 totalled 1,229,084, with New South Wales owning 490,922, Victoria 402,465, South Australia 127,519, Queensland 117,386, Western Australia 71,044 and Tasmania 19,748. Technicians were becoming increasingly concerned the 28 Silicon Chip morning test pattern broadcasts would cease, even proposing a levy system to pay for its continuance. Don’t blame us! Television receiver manufacturers were concerned their well-designed units connected to low-performance antennas or poor installations were presenting unsatisfactory pictures. Companies such as Kriesler therefore published antenna selection and installation guides, advising nuisance-calls to TV technicians regularly uncovered poor antenna installations. “The situation is a difficult one,” it said, “because while the service technician may suspect a faulty aerial system to be the cause, he has to exhaust the other possibilities first, because of the labour and expense involved in re-installing the aerial.” Kriesler then covered a multitude of factors, like the quality of the aerial, gain, use of many feeder stand-offs (to avoid feeder flutter), twists in the 300W ribbon, avoiding acute angles in the feeder, refraining from horizontal runs – especially near the ground or gutter, avoiding resting on metal, salt areas, use of coax to minimise ghosting, checking loop resistance and much more. Around this time, technicians such as John Williamson commenced replacing fault-prone paper capacitors with polyester. In fact some technicians regularly quoted to replace all the most vulnerable problematic capacitors to reduce service-calls. In time, John found this upgrade did indeed reduce service-calls. siliconchip.com.au The famous “Studio9” at Television City, Richmond, Victoria. Note the impressive lighting grid at the top of the picture – all run by an equally impressive electronic organ-like control panel, shown here insetted into the main pic. Outer space technology and Television. The world was exhilarated with space achievements, so television advertising gratuitously included references to space exploration, linking the latest sets to the excitement. Telstar, the world’s first communications satellite, was launched in 1962 enabling live TV pictures to be transmitted from the USA to France. Bandstand commenced with Brian Henderson. Performers who rocketed to fame included Col Joye, Peter Allen, Helen Reddy, the Bee Gees, Little Pattie, The Delltones, Judy Stone, Sandy Scott and Lucky Starr. The TV station monopoly situation prompted the Government to establish a third commercial network in 1963. Newspaper magnate, Rupert Murdoch, was an unsuccessful applicant and the licence was awarded to Sir Reginald Ansett, of the national airline company, Ansett-ANA. This was the beginning of the TEN network. TCN 9 and GTV 9 secured the rights to the first coaxial soccer ball GO TO www.rsaustralia.com Easier access to over 150,000 electronic, electrical and industrial products siliconchip.com.au August 2006 29 Filming the Mt. Dandenong Bushfires in 1962 atop an OB van. Cameraman is Russ Sefton, using a PYE camera and telephoto Canon lens. Note microwave dish, to feed the images to the station. cable between Melbourne and Sydney. On November 30, the Federal Election was seen simultaneously in Sydney, Melbourne and Canberra. Links were still not permanently established to most states, so Test Cricket was broadcast live and direct from Adelaide, using a transmitter link fitted in a DC3 aircraft. Australian made – for now. AWA was the only Australian manufacturer of television transmitters, just one of about ten major manufacturers of TV transmitters in the world. The first Australian-built TV transmitters were supplied to BCV-8 Bendigo, and GMV-6 Shepparton, both designed and built by AWA. In the same year, AWA completed a further fourteen complete 10kW TV transmitters for the Australian Post Office. All the electronic parts of TV transmitting systems including Vidicon cameras, (except Image Orthicon cameras) were manufactured by the company. Sony’s first all solid-state TV receiver, 8-301W, with 23 transistors, 17 diodes and 2 high-voltage rectifiers. The tube was an eight-inch and the set could be operated from mains or two 6-volt lead-acid unspillable batteries in an external screw-on battery box. The unit weighed only 13 lbs and consumed a tiny 11 watts. This model performed flawlessly and was instrumental in the Sony brand being widely accepted in USA. 30 Silicon Chip The following years saw rapid progress with the introduction of printed circuit boards, hybrid circuits, solidstate devices and the introduction of many models and screen sizes. In fact Admiral televisions had printed circuit boards from the onset. By 1968 when the futuristic 17-inch Telstar portable was released, AWA had manufactured 500,000 receivers. The government insisted on local manufacturing content and AWA Television receivers were proudly made entirely from components manufactured in Australia. In fact AWA fabricated all but the capacitors, resistors and some sundry sockets in-house. Considering the large number of component parts – over 2000 in a receiver – their performance and reliability proved to be outstanding, a credit to the Australian industry. However, in just a few short years, this was totally undone by government suddenly slashing tariffs, so Australian television and electronics production rapidly ceased. Brisbane and Adelaide secured new third channels (network TEN) and a second station commenced in Perth, during 1965. The Australian Broadcasting Control Board had advised against extra stations and introduced a fifty percent Australian content requirement in peak viewing for commercial television stations. Satellite connection. Satellite telecasting arrived in Australia in November 1966, through the earth station at Carnarvon, Western Australia. The Carnarvon earth station was built as a result of an agreement between 14 countries to establish a global satellite-based communications system by 1968. ATV0 (now TEN) produced the first colour TV program The Panasonic Orbitel, model TR-005 was advertised as ‘straight from the Space Age’. With a five-inch screen. tuning was via a single knob, from VHF to UHF. siliconchip.com.au the Middle East and western Asia, opened at Ceduna in South Australia and Carnarvon established a second antenna. The Carnarvon station was critical in providing communications for the NASA’s Apollo manned space mission program, leading to an astronaut on the moon in July 1969. Multipurpose hammer! “That’s one small step for man, one giant leap for mankind”: Neil Armstrong’s first step on the moon, the grainy images watched by millions live on TV in July, 1969. on Australian television when it televised the Pakenham Races in colour on June 15, 1967. Australia took part in two global satellite telecasts. “Our World”, a two-hour telecast screened simultaneously in 30 countries, with segments produced in 18 countries including Australia, and a live telecast from Expo 67 in Montreal. This Day Tonight commenced on the ABC in 1967 and was flown all over the country from the Sydney base. This situation did not last long, as soon better technology was available. OTC (the Overseas Telecommunications Commission) opened their earth station at Moree in 1968, the first regularly available television relay service. One of the first presentations was an announcement by President Johnson that he would not be seeking re-election. By this time, the ABC had set up microwave links between Sydney and Melbourne and its regional stations in the country. The ABC, however, rarely used these links for anything other than sports, a field they dominated. A second earth station linking Australia with Japan, the western Pacific, and the US opened at Moree, NSW in March 1968. Neil Armstrong placed the first human footprint for live television from the moon. Most who saw the live, noisy pictures can remember exactly where they were at the time. Australians watched enthralled as the astronauts carried out their activities and televised the wonder of the alien landscape. Suddenly, screens worldwide went black. Houston Control checked all links and frantically searched for solutions to restore the historic footage for an audience of billions. They were nearly certain the technical problem was on the moon. Suddenly live pictures reappeared. Houston asked the astronaut what he had done. The reply, ‘I hit the camera with my (prospecting) hammer!’ GTV9’s coverage entered the record books as the longest continuous live broadcast on television. While the OTC was highly instrumental in the television transmission of the lunar landing and associated communications, the plug was pulled on the Australia/England HF (high frequency) link between London and Melbourne, after continuous service since 1927. Now stations could broadcast live news daily from London via the newly opened Satellite Communications Earth Station at Ceduna. Darwin finally joined the television era, the last capital to commence television broadcasts, in 1971. Big is beautiful Early Australian television design was inspired by American sets with elaborate closing cabinets, though our designs were less ornate. Premier models of Australian sets were finished in beautiful highly-polished laminated wood. Compared to other countries, Australians had a much greater interest A globe-trotting Kangaroo. “Skippy” commenced in 1968, growing to viewing in 128 countries around the world. Australia became connected, as a second earth station linked Australia with Japan, the western Pacific and the US, from Moree. A third, the link to Britain, Europe, Africa, Kriesler’s 1968 Multisonic 3-in-1, shown here not just because it was a great performer, more so because of that strange “thing” on top. It’s a 3-function wired remote control. Channel changing was one direction only! (Reproduced larger at left.) siliconchip.com.au August 2006 31 in monster three-in-one entertainment centres, with radio, television and hifi in one package. Rather than an ingenious integration of components, many featured a current model TV, placed in the same cabinet as a radiogram but with little or no interconnection. In fact, the 25-inch TV in Kriesler’s 1968 Multi-Sonic TV Theatre (pictured overleaf ) was totally independent of the radio and record-player, with a small loudspeaker of its own. The speaker complement included eight-inch woofers and electrostatic tweeters. By radiogram standards of the time, the ceramic pickup head, valve amplification and electrostatic tweeters represented the peak of domestic valve design quality, with a sweet, crisp sound. Only top-end audiophile valve equipment was superior. Kriesler included servicemanfriendly ideas, like a circuit of the radiogram attached to the rear, the TV circuit inside the unit and even printed directions on the rear cover to guide on its removal. No expense was spared, packing in so much heavy technology and quality wood finishes, these monsters needed two strong men to lift for delivery. Luxury at a price Noel Gibson joined Gainsborough Furniture, manufacturers of fine furniture in 1971. Radio, TV and radiogram manufacturers relied on leading furniture companies to build their cabinets. Gainsborough furniture moved to the Astor/Electronic Industries ‘Radio City’ complex in Clayton, producing fine TV and Radiogram cabinets, along with domestic furniture, plus Travelodge hotel furniture. Total production included fabricating and welding steel, plus chrome baths, for metal components used in the furniture production. Cabinets for Astor receivers were manufactured entirely in-house at Gainsborough, from the slicing of raw wood for laminated veneers, through to completed cabinets. Stunning wood veneers included the now virtually extinct Russian burl walnut. Only very old Russian walnut trees from a cold climate but with little frost could be sliced to exhibit the awesome patterns prized by furniture-makers and customers. After laminating, the cabinets were finished in incredibly hard polyester, buffed to a very high gloss in a massive buff. Polyester high-gloss finish was sprayed onto furniture in a ‘wet booth’. Polyester is the result of a combined A and B catalyst, later found to be highly carcinogenic, so it was replaced by polyurethane. Unfortunately most of the applicators later died, due to the carcinogenic effects of the chemicals. After application, huge European men – specifically chosen for the job – rested enormous three in one cabinets on their bellies, pushing against a metre-wide buff wheel. Few finishes before or after compare to the depth, gloss, lustre and resilience of this finish. Plating onto plastic was a new technique employed by Astor in another plant, to feature on fascias and knobs, converting them into dazzling chrome or gilt. For a time, Gainsborough also made TV cabinets for other companies, like PYE and HMV. Noel recalls when Philips took over, they bought European ideas, ten years ahead of local production. Soon Philips made TVs in vinyl-finished plastic cases, with wrap-around curved style. As vinyl was a print, almost any wood appearance or pattern was possible. By the mid-seventies, production was upgraded by Philips, with machines to do the work of three or four men. You are naughty The Seventies was a radical period and this was also reflected on the nations TV screens. Leading the way in Australian TV’s loss of innocence were racy soap opera dramas Number 96, The Box and the cult hit comedydrama Alvin Purple. By 1973, Number 96 was the most popular program on Australian TV, with The Box running second in 1974. Classic TV shows started their run in 1971. Matlock Police from Crawford Productions, broadcast for five years on 0-10, Young Talent Time started an 18-year series on the 0-10 Network, Hey, Hey It’s Saturday was a Saturday morning cartoon show on GTV9 and A Current Affair with Mike Willesee, premiered on Nine. Beauty and technology Visitors to Victoria’s bayside areas in the 70s enjoyed television and radio beach broadcasts, so people could leave the water and enjoy a free live-show, see the live radio set-up, then later see highlights on TV. 32 Silicon Chip Visitors to Victoria’s bayside areas in the 70s enjoyed television and radio beach broadcasts, so people could leave the water and enjoy a free liveshow, see the live radio set-up, then later see highlights on TV. Activities and competitions were presented on a large stage, which was moved around the most popular beach areas. Channel 9 and radio station 3AK each presented different programs. 3AK playing popular music and GTV9 siliconchip.com.au recording the events to present in the evening news. The highlight was the Miss Victorian Beach Girl quest. 3AK’s equipment was housed in a rather makeshift custom audio console, with modest domestic tape recorders, basic by today’s standards, but it did the job. Well-known television presenters and judges included Rosemary Margan and ‘baby’ John Burgess. Blind 60’s rock singer and radio announcer Grantley Dee was in the line-up for the 3AK broadcasts. In 1974, Sydney Harbour Bridge rigger Paul Hogan, becomes a comedy star and “Countdown”, while ‘Molly’ Meldrum starts a 12-year run on ABC. Colour our world Only the first broadcast of television can compare to the first broadcast of regular colour programmes, on March 1, 1975. Channel Nine launched “The Don Lane Show” resulting in an eight year run. TEN10 launched the first one-hour news service – “Eyewitness News” hour. An infamous ‘bombblast’ episode of Number 96 wiped out four regular characters in a bid to reinstate top rating position and Graham Kennedy made a ‘faaark, faaark’ crow call while Rosemary Margan read a live advertisement on “The Graham Kennedy Show”. The ensuing row forced Kennedy from the network. AWA manufactured monochrome televisions at their Ashfield site until the introduction of colour, when they moved to a new facility at the AWV factory Rydalmere near Parramatta NSW. Australian production and thousands of jobs were forced out of the market after the government slashed tariffs in 1976, rather than a long, gradual phase out. The future is here Television is now changing at a frenetic pace. In 2005, Sony made their last CRT and posted profit losses, while electronic equipment these days usually displays the ‘made in China’ label. Where will television and video technology advance in the next decade? Only the brave would predict. Who would have anticipated the demise of the VCR for DVD players that do not record? The first attempt, Laservision, was rejected by the public. Then a smaller DVD disc made VCRs dinosaurs and new higher-capacity discs are about to become popular. Whatever the future holds, the pioneers of black and white television paved the way for tomorrow’s exciting (and expensive) large screen colour entertainment experiences. SC Credits and references are shown at: www.aaa1.biz/sc.html A young Pete Smith in Studio 9 sound booth. Pete is still doing voiceovers for Channel 9. siliconchip.com.au August 2006 33 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au Amaze your friends with this highly visible animated clock project. It’s based on a PICAXE micro, a quartz clock movement and a large quantity of low-cost diodes and LEDs. The results will surprise you! Program & circuit design: RON RUSSO Article & PC board design: CLIVE SEAGER Clive Seager is Technical Director of Revolution Education Ltd, the developers of the PICAXE system. Novel PICAXE LED Chaser Clock I T’S ALWAYS INTERESTING to see the many and varied projects that people create using PICAXE chips. When first introduced to this LED Chaser Clock from Ron Russo, I was at first taken aback with the complexity of the prototype; how could it possibly have been made by hand? It was intricately assembled by wiring and soldering together well over 200 components, all without a PC board! As Ron himself stated, “the wiring is kept to a minimum by the strategic 40 Silicon Chip (piggy-back) placement of the shift registers and the unique way I coupled the two banks of registers with the isolation diodes. The results of this method appear more like a work of art than a rats nest, which is the usual outcome when no circuit board is used.” However, most of us would not have a steady enough hand or the patience to build such a masterpiece. Therefore, this incarnation of the project does include a PC board so that everyone has a chance to build it! As can be seen from the photos, the Chaser Clock is a marriage between an analog quartz clock movement and a circular array of LEDs. A continuous visual display is created by synchronising LED effects with the movement of the clock’s seconds hand. Once every second, a “chaser” LED starts from the 12 o’clock position and appears to move around the dial in an anticlockwise direction towards the seconds hand. When it meets the seconds hand, the LED appears siliconchip.com.au to “freeze” under the pointer (ie, it remains illuminated). So at each tick of the clock, one more LED is illuminated. This creates an arc of light that trails the seconds hand. When the seconds hand reaches 12 o’clock, the arc closes to form a complete circle of light, whereupon all LEDs are turned off and the cycle repeats over. It’s difficult to visualise this effect simply by reading about it, so we’ve posted a short video of Ron’s prototype clock in action on the SILICON CHIP website. You’ll find it in the downloads section for this month. Circuit basics The complete circuit diagram for the chaser clock appears in Fig.1. A PICAXE-08 microcontroller (IC1) drives the whole show with the aid of timing pulses from the analog clock mechanism. The clock is used intact, with a pair of diodes steering the pulses from its coil to input3 of the micro. A 2.5V supply for the clock mechanism is derived from the 5V rail by dividing it down with two 330W resistors, while a 100mF capacitor supplies peak coil current. All 60 LEDs are driven by 74LS164 8-bit shift registers. Every tick of the clock, the PICAXE-08 program performs a few simple calculations and then manipulates the data (A&B), clock (CLK) and clear (CLR) inputs of the shift registers to produce the magical effects mentioned earlier. The 74LS164 shift registers are divided into two paralleled banks, with isolation between the banks provided in the form of series-connected diodes. Registers SR1-SR8 handle the LED chase effect, while SR9-SR16 handle the arc of light that follows the seconds hand. With this circuit arrangement, about 10-15mA of current flows through each LED. No separate current-limiting resistors are required, which greatly simplifies the assembly task. Some might be wondering how this simple scheme is possible; don’t we always need to limit LED current in a logicdriven circuit? The answer is usually yes, of course. However, by design, the 74LS series TTL logic devices incorporate a certain resistance in the upper NPN output transistor’s collector circuit (see Fig.3). In the case of the 74LS164, siliconchip.com.au this amounts to about 120W. Accounting for the impedance of the NPN output and the forward voltage drop of the LEDs and series diodes, the total current sourced from each output shouldn’t exceed about 15mA. This works very well, with the total power dissipation for each IC remaining within safe limits. Note that current will vary between different brands of LEDs and shift registers, so for best results use devices from the same manufacturer throughout. Do not be tempted to substitute devices from another logic family. For example, while 74HC164 devices are pin compatible with the 74LS164, they have an entirely different output structure and will self-destruct in this circuit! Power supply Due mainly to the large number of LEDs, overall current consumption is quite high, starting at about 200mA and increasing to over 900mA as the arc of light grows. The original circuit was developed using an on-board 7805 regulator with a 9V supply but when using this setup the regulator gets very hot. Although a sizeable heatsink would keep the regulator within operating parameters, there is still the possibility of heat damage to surrounding materials. The final version of the clock was therefore developed for use with an off-board regulated 5V power sup- Par t s Lis t 1 PC board 1 2-way 5mm pitch terminal block 1 miniature tactile push-button switch (S1) 1 8-pin IC socket 16 14-pin IC sockets 1 analog clock mechanism (see text) Semiconductors 1 PICAXE-08 (IC1) 16 74LS164 8-bit shift registers (SR1-SR16) 1 1N5817 (or 1N5819) Schottky diode (D1) 2 BAT85 (or 1N5711) Schottky diodes (D2 & D3) 120 1N4148 small-signal diodes (D4-D123) 12 5mm yellow LEDs 48 5mm green LEDs Capacitors 5 100mF 16V 8 100nF polyester Resistors (0.25W 5%) 1 2.2kW 1 470W 2 330W Also required (not in kit) 5V DC 1A (minimum) regulated power supply (eg, Altronics Cat.M 8909) The kit includes two quartz clock mechanisms like the one shown here. These are widely available for just a few dollars. If you want to use a dark clock face design, you can paint the black hands a lighter colour (eg, yellow) to obtain a good contrast. August 2006 41 Fig.1: here’s the (almost) complete circuit diagram for the clock. As noted, we’ve left out some portions to make it easier to follow. A PICAXE micro (IC1) manipulates 16 shift registers to control the light show, using pulses from the clock mechanism for timing. Clever arrangement of the shift registers and LEDs allows the use of the smallest PICAXE device in the range, with the program code consuming only 76 bytes! ply, such as the Altronics M-8909. However, if you prefer to build your own regulated power supply, you’ll find a suitable circuit in Fig.4. Note that any supply should be located no more than 2m from the clock and the power leads should be formed from heavy-duty hookup wire. 42 Silicon Chip Power is connected to the board via a 2-way screw-terminal block. A diode in series with the positive input (D1) is included for protection against accidental reversal of the leads. We’ve specified a 1N5817 Schottky diode to minimise voltage losses, so you should get a reading of close to 4.7V when measuring between the +5V and GND rails on the PC board. Putting it together Assembly is very straightforward, but time consuming! The PC board is a double-sided design (tracks on both sides), so take care that you have siliconchip.com.au the board the right way up. All of the components except the LEDs mount on side with the white silk screen overlay! Put all of the LEDs aside for the moment and begin by fitting the diodes and resistors. Take care to insert each diode around the right way; the cathode (banded) ends must go in as shown on the overlay diagram (Fig.2). Also, don’t mix up the 1N4148 and BAT85 types, which may look very similar depending on the brand supplied. siliconchip.com.au Add all the IC sockets next, orienting the notched (pin 1) end as indicated. Follow with the few remaining components, including the reset switch, terminal block and capacitors. Note that the electrolytic capacitors are polarised devices and must be installed with their positive leads oriented as shown. The final task is to install all of the LEDs. As shown on the overlay diagram (Fig.2), there are two possible positions for the LEDs. Most constructors will probably go for the outer circle but some clock designs may suit the inner circle. Don’t install LEDs in both positions. Before soldering the LEDs, work out carefully what your clock face design is going to look like and how it is going to fit to the PC board – you may wish to mount the LEDs several millimeters off the PC board. Whatever your design, remember that the LEDs are fitted on the reverse side of the PC board to all the other components! August 2006 43 With all the LEDs in place, plug the 74LS164 shift registers into their sockets. It’s very important that the notched end of each IC lines up with the notch in its socket. Clock mechanism This view shows the fully-assembled clock prototype. Note that there have been some changes to the PC board since this photo was taken – just follow the parts layout diagram of Fig.2. The final task is to “hack” the clock mechanism. This requires a steady hand and lots of patience! The aim is to solder four wires to the clock PC board; one to each coil end and two to the battery connection points. Start by holding the assembly over a tray to catch any gears that may drop out. Use a flat screwdriver blade to carefully open the clock’s plastic case by sliding it under the tabs on either side of the casing. Don’t bend the plastic too far or it will snap! You then have to remove the gears to get access to the coil and its small PC board. It’s a good idea to take notes as you remove each piece, as you have to rebuild the gearbox later! Before lifting out the circuit board, study the assembly carefully to see how the two battery connector strips make contact with the PC board. Make a note of which PC board pad connects to the positive side of the battery. Lift out the PC board complete with its plastic surround. You will see two + – Start by removing the back half of the clock’s casing. This can be achieved by sliding a flat-bladed screwdriver under the tabs on either side of the casing. Don’t bend the plastic tabs too far or they will snap! 44 Silicon Chip After removing several of the nylon gears, you’ll be able to lift out the complete coil assembly. Solder light-gauge wires to the coil and battery pads on the PC board, positioned as shown here. Make a note of which wire goes where – so that you’ll be able to hook them up correctly once it’s reassembled. Remove all of the gears and the two battery contacts from the case half. Cut a slot roughly as shown to allow the four wires to pass out of case once it is closed, then reassemble the lot in reverse order. Don’t force the case halves together – it you feel any significant resistance, then a gear has most likely jumped out of position! siliconchip.com.au Fig.2: follow this diagram and the legend on the board when assembling your clock. Don’t mix up the different types of diodes and take care with the orientation of the ICs, diodes, LEDs and 100mF capacitors. Table 1: Resistor Colour Codes o o o o siliconchip.com.au No. 1 1 2 Value 2.2kW 470W 330W 4-Band Code (1%) red red red brown yellow violet brown brown orange orange brown brown 5-Band Code (1%) red red black brown brown yellow violet black black brown orange orange black black brown August 2006 45 Program Listing: PICAXE Clock symbol Sec = b13 symbol Leds = b12 symbol TmLength = w0 symbol ChaseClock = 0 symbol NewSec = 1 symbol NewMin = 2 symbol ChaseData = 4 'seconds counter 'chase counter 'duration of pulsout to match chase with second 'pin0 'pin1 'pin2 'pin4 (chase data output & reset input for sync) MAIN: pause 100 high NewMin goto RES_MIN 'settling time 'release SR9-SR16 reset (MR) inputs 'go initilise for start of new minute LOOP: input 4 if input4 = 1 then RES_MIN if input3 = 1 then NXT_SEC 'set pin 4 as input 'if sync button is pressed initialise for new minute 'else a high-going pulse on input 3 indicates one second has elapsed, 'so start a new second ' NOTE: Some analog clocks have low-going rather than high-going pulses (change the above line to suit). goto LOOP NXT_SEC: output 4 if Sec = 0 then RES_MIN Sec = Sec – 1 'loop until a clock pulse occurs 'set pin4 to output to send chase data 'if min is up then go reset minute 'else one sec has elapsed so decrement secs ' Calculate optimum time factor so that all intended LEDs are illuminated just before the current ' second is up. A multiplication factor of 90 is optimum for the PICAXE-08. TmLength = 61 – Sec TmLength = TmLength * 90 CHASE: high ChaseData 'set chase data bit high for Leds = Sec To 0 Step –1 'count back starting from relevent second pulsout ChaseClock, TmLength 'pulse with calculated duration to increment clock input of chase 'regs(SR1-SR8). low ChaseData 'after first clock pulse, set data low for rest of chase next Leds 'do rest of LEDs until this sec finished low NewSec pause 1 high NewSec goto LOOP RES_MIN: Sec = 60 low NewMin pause 1 high NewMin Fig.3: the equivalent circuit for each output (O0-O7) of a 74LS164 shift register. The resistance in the collector leg of the high-side transistor greatly reduces the maximum current that these devices can source. 'zero SR1-SR8 outputs, clock SR9-SR16 'make pulse 1ms wide 'return high very fine wires connecting the coil to two small pads near the edge of the PC board. These are only as thick as a human hair, so you may need a bright light and a magnifying glass! Now carefully solder two light-gauge hookup wires (about 150mm long) to the coil connection pads. Study the orientation and dress of the wires in the photos before you begin. The kit for this project includes two PP3 battery snaps that can be sacrificed for their black and red wires. Simply cut off the battery snaps and use the pre-tinned wire ends for the clock connections. Alternatively, you could use rainbow cable for the job. Only hold the soldering iron in 'power up or minute is up or syncro reset . . . 'reset all SR9-SR16 outputs to zero 'make pulse 1ms wide ' As the first 4 outputs of SR9 are not connected to LEDs we must send a dummy run of 4 clock ' pulses to shift regs SR9-SR16 to start at LED60 (SR9 output O4). This will also pulse the reset (MR) ' inputs of SR1-SR8, zeroing their outputs ready for the new minute. for B10 = 1 to 4 pulsout NewSec, 10 next if input4 = 1 then LOOP goto NXT_SEC 46 Silicon Chip 'check input again if sync button still pressed 'else go start a new minute Ron Russo’s prototype was made by hand wiring over 200 components – all without a PC board. The ICs were even piggy-backed! siliconchip.com.au place for a fraction of a second – if a joint is overheated the pad will lift off or the coil wire come adrift. Next, solder the two power wires. Thankfully, these are easier to work with, as the pads are much larger. Be sure to note the positive (+) and negative (-) wires for later identification. Important: it is not necessary to remove the coil and its PC board from the plastic surround. However, you must be very careful not to contact the gear posts that are part of the plastic molding with the barrel of your soldering iron! Remove the two metal battery contact springs from the plastic casing and use a sharp knife to cut a small opening in the plastic to allow the four wires to pass through (see photos). You can now reassemble your clock mechanism, with the aim obviously being to get all of the gears in the right places! Finally, mount the clock to the chaser PC board and solder the four wires in position. Fit the hands and then you’re ready to go! Made a mistake during the assembly or lost a gear? Don’t worry; the kit includes a spare clock mechanism! Fig.4: the clock must be powered from a regulated 5V DC supply with at least a 1A capacity. High-power regulated plugpacks are readily available but if you want to use an unregulated plugpack, you’ll need to add a 5V regulator circuit. Here’s a suitable circuit based on the popular 7805. PICAXE program The PICAXE chip in the kit is supplied pre-programmed with Ron’s original program. However, the fully commented listing is included here for those who wish to experiment. In particular, the timing multiple (90) may need tweaking slightly if your chaser runs too fast or too slow. A programming socket is not included on the PC board. However, it’s a simple matter to reprogram the micro in any of a number of different project boards. If you don’t already have a suitable board and programming cable, check out the Schools Experimenter Starter Pack (part. no. AXE092S) or the PICAXE-08 Starter Pack (part no. AXE-003). Both are available from MicroZed Computers; see the adjacent panel for contact details. Synchronisation to the seconds hand is achieved by pressing the reset button and then waiting for the seconds hand to reach 60. The LED display will be blanked and then start from 1 when the button is released. The clock will stay in sync until power SC is removed. siliconchip.com.au This side of the board looks very bland without the clock face. You don’t get one of these in the kit but you can easily create your own from a favourite photograph or desktop wallpaper (we used “The Matrix” theme wallpaper). The numerals can be added in just about any graphics program and the result printed out on photographic quality stock. Where To Buy A Kit Of Parts The PC board copyright for this project is owned by Revolution Education Ltd. Complete kits (part no. AXE115S) are available from authorized PICAXE distributors – see www.microzed.com.au or phone MicroZed on 1300 735 420. Note: kit does not include clock face (see above). August 2006 47 Re s u r r ec t y our o l d L P s an d 7 8 s . . . Build this magnetic cartridge preamplifier an d d u b t h em on t o CD s or MP 3 f ile s Do you have an old turntable but no RIAA inputs on your preamplifier? If so, you need this preamplifier for playback and for converting them to CD or MP3 format. By JOHN CLARKE D O YOU HAVE a collection of old vinyl or 78 RPM records languishing in a cupboard? Perhaps you should resurrect them before they deteriorate further. To do this you need a computer with a CD or DVD burner, suitable software and a preamplifier. The preamplifier described here can be built to suit vinyl or 78 records and is self-contained. You can build it into a 48 Silicon Chip diecast metal case or underneath your turntable. Of course some people will just want to listen to their records, without the bother of feeding signals into a computer and so on. This preamplifier will suit those people too but ultimately, we think that anyone who has become used to the high-quality sound of compact discs or MP3 players will be disappointed with the clicks and pops and surface noise on LPs and 78s. So by all means build the preamplifier to play your old records but you will probably end up going the whole way and dubbing your records to CD. In the process, you can filter out most of the clicks and noise and once again enjoy those old favourites. If you only have vinyl records (LPs) you can build this project as a standard preamplifier with RIAA equalisation but if you want to play 78s, you will need to choose one of three equalisation curves which can also be built in. You will also need a turntable that can play at 78 RPM and a cartridge that accepts the correct stylus (more details on this in our feature article on transferring LPs to CD next month). siliconchip.com.au Fig.1: the preamplifier circuit is based on two LM833 dual op amps (one channel only shown). It includes three sets of feedback networks (R1-R3 & C1-C2) and the values are chosen to give the equalisation required (see tables). Ideally, the turntable should have a speed adjustment so that the pitch can be changed but this is a rare feature. Alternatively, commonly available recording software can adjust the pitch when you dub the records to CD. The SILICON CHIP RIAA Preamplifier is housed in a diecast box and has RCA sockets for the input and output connections. It has a control to set the output level and is powered using an AC plugpack. By the way, this preamplifier supersedes the preamplifiers described in March 2002 and April 1994. in Fig.1. This shows the left channel only; the right channel is identical. Some readers may wonder why we have used LM833 dual op amps instead of the newer high-performance OPA2134 devices featured in our recent Studio Series Preamplifier. In fact, they could be used but since the signal source is a magnetic cartridge playing vinyl or 78 RPM shellac records, any slight performance improvement will be negligible and unable to be discerned by listening. The input signal is fed through in- Specifications Signal-to-noise ratio: -84dB unweighted with respect to 10mV in and 560mV out (-89dB A-weighted) Total harmonic distortion at 1kHz 10mV in and 560mV out: 0.014% Crosstalk: -79dB at 100Hz, -80dB at 1kHz and -70dB at 10kHz Circuit description Signal handling: 140mV before clipping The preamp circuitry is based on two LM833 dual op amp ICs, as shown RIAA accuracy: typically within 1dB from 20Hz to 20kHz (see graph) siliconchip.com.au August 2006 49 Par t s Lis t 1 PC board, code 01108061, 102 x 81mm 1 blank PC board, 70 x 30mm 1 diecast box, 119 x 94 x 57mm 1 12VAC 250mA plugpack 1 SPST slimline toggle switch (S1) 2 dual RCA PC-mount sockets 1 5-pin DIN PC-mount socket (optional) 1 2.5mm PC-mount DC socket 1 16mm dual 10kW log PC-mount pot (VR1) 2 crimp eyelets 1 green banana socket 6 2-way 2.5mm pin headers (from a 12-way header strip) 2 2.5mm jumper plugs 2 ferrite beads 4mm OD x 1.5mm ID x 5mm (L1,L2) 4 10mm M3 tapped spacers 4 adhesive rubber feet 4 M3 x 6mm screws 2 M3 x 10mm screws 2 M3 nuts and star washers 2 No.8 self-tapping screws 7 PC stakes 1 150mm length of green hookup wire 1 150mm length of red hook-up wire 1 150mm length of 0.7mm tinned copper wire Semiconductors 2 LM833 dual op amps (IC1,IC2) 1 7812 12V regulator (REG1) 1 7912 -12V regulator (REG2) 2 1N4004 1A diodes (D1,D2) 1 5mm red LED (LED1) Capacitors 2 1000mF 35V PC electrolytic 6 47mF NP or BP non-polarised electrolytic 1 10mF 35V PC electrolytic 2 10mF 16V PC electrolytic 2 1mF NP or BP non polarised electrolytic 2 560pF ceramic 2 100pF ceramic Resistors (0.25W 1%) 2 47kW 4 150W 2 7.5kW 1 39W 4 1kW RIAA components 2 200kW resistors 2 16kW resistors 2 15nF capacitors 2 4.7nF capacitors 50 Silicon Chip Fig.2: the RIAA response curve. The bass and treble turnover frequencies are set by the RC components in the feedback network connected to IC1a in the preamplifier. ductor L1, a 150W resistor and a 47mF capacitor to pin 3 of IC1. The 47kW resistor and 100pF capacitor provide the loading for a typical magnetic cartridge. As well, the 100pF capacitor functions as an RF input filter, in conjunction with inductor L1 and the 150W resistor. IC1a’s gain is set by the feedback components between pin 1, pin 2 and ground. The 1kW resistor and 47mF non-polarised capacitor set the low-frequency roll-off for this stage at around 3Hz. We have shown three sets of feedback components (C1, C2, R1, R2 & R3) and these can be selected to provide the RIAA or other equalisation responses for older recordings. The three sets of feedback components are labelled SET1, SET2 and SET3 and the particular equalisation SET is selected using jumper plug LK1, LK2 or LK3. The feedback components for the various equalisation curves are shown in Tables 2 & 4. High-pass filter IC1a’s output appears at pin 1 and is fed to pin 3 of IC2a via a high-pass filter comprising a 1mF capacitor and a 7.5kW resistor. This filter rolls off Why So Many Choices For Equalisation? Readers may be surprised to see all the various equalisation curves for vinyl (45 & LP) and 78 RPM records. It is not well-known these days that before the recording industry standardised on the RIAA curves, the bigger recording companies had their own equalisation curves, hence there were curves such as Decca’s ffrr (it stood for “full frequency range recording”), EMI, NARTB and Columbia. The situation was even more chaotic before vinyl LPs came on the scene and there was more choice (and confusion) with 78 records. Hence, some of the equalisation curves used included Decca (EMI) 78, Westrex and so on. The reason for including these different sets of components in Tables 2 & 4 is so that if you can identify the company that made a particular recording, you can then select the appropriate equalisation characteristic. Note that we have also shown values for flat frequency response (ie, no equalisation) and tape head equalisation. siliconchip.com.au Table 1: Microgroove 45 & LP Frequencies Curve Treble Turnover Bass Turnover Lower Bass Turnover Cut at 10kHz Boost at 50Hz RIAA 2.1215kHz 500Hz 50.5Hz -13.6dB 17dB ffrr LP 3kHz 500Hz 100Hz -10.5dB 12.5dB EMI LP 2.5kHz 500Hz 70Hz -12dB 14.5dB NARTB 1.6kHz 500Hz – -16dB 16dB Columbia 1.59kHz 500Hz 100Hz -16dB 12.5dB Table 2: Components For Microgroove 45s & LPs Curve R1 R2 C1 C2 R3 RIAA 16kW 200kW 4.7nF 15nF – ffrr LP 220kW 18kW 15nF 3.3nF 270kW EMI LP 330kW 18kW 15nF 3.9nF 270kW NARTB 2.2nF 18kW 18nF 5.6nF//390pF 270kW Columbia 100kW 18kW 18nF//2.2nF 5.6nF//390pF 270kW Table 3: Coarse Groove 78 Frequencies Treble Turnover Bass Turnover Decca 78 3.4kHz 150Hz – -9dB 11dB ffrr 78 6.36kHz 250Hz 40Hz -5dB 12dB Westrex Flat 200Hz – – 15dB Blumlein Flat 250Hz 50Hz – 12dB BSI 78 3.18kHz 353Hz 50Hz -10.5dB 14dB Curve Lower Bass Turnover Cut at 10kHz Boost at 50Hz Table 4: Components For Coarse Groove 78s Curve R1 R2 C1 C2 R3 Decca 78 open 18kW 68nF 3.3nF 270kW ffrr 78 220kW 18kW 33nF 1.5nF 270kW Westrex 18nF 18kW 33nF – 270kW Blumlein 220kW 18kW 33nF – 270kW BSI 78 220kW 18kW 22nF 3.3nF 270kW Table 5: Components For A Flat Response Gain R1 R2 C1 C2 R3 x1 link 1kW – 4.7nF – x 11 link 10kW – 470pF – x 101 link 100kW – 47pF – Table 6: Components For Tape Head Equalisation NAB R1 R2 C1 C2 R3 – 3.6kW – 15nF 200kW These tables show the components necessary to achieve the various response curves required to play back from vinyl records and other recording surfaces, including Shellac 78s and tape heads. The parts necessary to achieve a flat response (with various gains) for general-purpose use are also shown. siliconchip.com.au August 2006 51 Table 7: Capacitor Codes Value 68nF 33nF 22nF 18nF 15nF 4.7nF 5.6nF 3.9nF 2.2nF 1.5nF 560pF 470pF 100pF 47pF μF Code .068mF .033mF .022mF .018mF .015mF .0047mF .0056mF .0039mF .0022mF .0015mF NA NA NA NA EIA Code 683 333 223 183 153 472 562 392 222 152 561 471 101 47 IEC Code 68n 33n 22n 18n 15n 4n7 5n6 3n9 2n2 1n5 560p 470p 100p 47p Above: this view shows the fully assembled PC board with all feedback component sets installed. In practice, you would normally only install one feedback set (typically for RIAA equalisation) and omit the parts for the other two sets. The PC board is installed in the case by angling it as shown here, so that the RCA sockets and the pot shaft go through their respective holes. It then sits on Nylon spacers that are pre-fastened to the bottom of the case and is secured using machine M3 x 6mm screws. 52 Silicon Chip signals below 20Hz to reduce rumble from the turntable. Signal above 20Hz is free to pass to the next stage of amplification within IC2a. The gain of op amp IC2a is adjustable using potentiometer VR1. When VR1 is set fully anticlockwise, its resistance is zero and IC2a has a gain of 1. Conversely, when the wiper is fully clockwise, VR1’s resistance is 10kW and so the gain is 11. The 560pF capacitor across VR1 rolls off the gain at higher frequencies to prevent oscillation. The outputs from IC2 are fed to the RCA sockets via 150W resistors, another measure to prevent oscillation because the of the capacitance of the screened signal leads. Power for the circuit comes from a 12VAC plugpack which is fed to two diodes and two 1000mF capacitors to produce positive and negative supply rails. These are fed to 3-terminal regulators to derive ±12V DC rails. Note that the plugpack feeds the two diodes via a 39W resistor to limit the siliconchip.com.au Fig.3: follow this parts layout and wiring diagram to build the preamplifier. Note that you can select only one set of feedback components at a time using either links LK1 or LK2 or LK3. Table 8: Resistor Colour Codes o o o o o o o o o o o o o o No. 1 1 1 2 1 2 1 2 1 2 4 4 1 Value 330kW 270kW 220kW 200kW 100kW 47kW 18kW 16kW 10kW 7.5kW 1kW 150W 39W peak current into the 1000uF capacitors. This minimises any tendency for 100Hz rectifier buzz to become audible in the preamp’s output signal. The case of the preamp may be earthed should this be necessary to siliconchip.com.au 4-Band Code (1%) orange orange yellow brown red violet yellow brown red red yellow brown red black yellow brown brown black yellow brown yellow violet orange brown brown grey orange brown brown blue orange brown brown black orange brown violet green red brown brown black red brown brown green brown brown orange white black brown avoid mains hum in the signal. In most cases, this will not be required. Building the preamplifier The new preamplifier is built on a PC board coded 01108061 and measur- 5-Band Code (1%) orange orange black orange brown red violet black orange brown red red black orange brown red black black orange brown brown black black orange brown yellow violet black red brown brown grey black red brown brown blue black red brown brown black black red brown violet green black brown brown brown black black brown brown brown green black black brown orange white black gold brown ing 102 x 81mm. It fits into a diecast box measuring 119 x 94 x 57mm. Fig.2 shows the wiring details. It’s a good idea to first check the PC board for any defects such as shorts between tracks or for any breaks in the August 2006 53 earth available (eg, an earthed metal case) to connect to the green banana socket. The shield consists of a piece of PC board 70 x 30mm and is soldered to the PC stakes in the position shown. LED1 mounts high on its leads so it can be bent over and inserted into a hole in the side of the case. Case work The metal case can be earthed (via the banana socket) if mains hum is a problem. This usually won’t be necessary, however. copper areas. Repair these if necessary and also check that the board has the correct hole sizes for the components such as the RCA sockets, DC power socket and the dual ganged potentiometer. Now begin the assembly by installing all the links, PC stakes and 2-pin headers. Before you insert the resistors, decide on the value of components you are going to use for each of the equalisation sets. In most cases you would only use one set for the RIAA equalisation (the others can be left out). Note that you need to place the Fig.4: use the 5-pin DIN plug only if you need an earthed supply. The Jaycar MP-3022 earthed 17VAC plugpack can supply the required AC power and earth. 54 Silicon Chip same components in both the left and right channels for each set. Install the resistors using the colour code table (Table 8) as a guide to finding the correct values. It’s also a good idea to use a digital multimeter to make sure they are correct, as some of the colours can be difficult to decipher. The two ferrite beads are mounted with short lengths of tinned copper wire passed through them. The ICs can go in next, taking care to orient them correctly. Install the two diodes and the two regulators and make sure the 7812 and the 7912 types are placed in the correct positions. Next up are the capacitors. The polarised electrolytic types must be mounted with the correct polarity, as shown on the overlay. Also, make sure you use the 35V 10mF capacitor adjacent to IC2. The NP (non-polarised) or BP (bipolar) electrolytic capacitors can be inserted either way around. Use Table 7 as a guide to selecting the non-electrolytic capacitors. Next, mount the two RCA sockets, the potentiometer and the DC socket. The 5-pin DIN socket can be installed later if you find that you need an earthed supply and there’s no mains The metal case will require drilling out to accommodate the two stereo RCA sockets, the potentiometer and the LED on the front face of the case. On one side, holes are required for the earth screw, the power switch and the DIN socket if used. At the rear, holes are required for the DC supply socket and the banana socket. Mark and drill these holes out. The slot required for the switch is best made by drilling about three holes within the cutout area and then filing it to shape. Four holes also need to be drilled in the base for the plastic spacers for the PC board. That done, attach the four rubber feet to the base of the case and then wire up the switches and earth connections as shown in Fig.3. Testing Connect power to the preamplifier and check that the LED lights when power is switched on. If it does not light, then perhaps the LED is installed the wrong way around. Next, measure the voltage between pins 4 & 8 of IC1 and IC2. It should be close to 24V DC in both cases. If this is correct, you are ready to connect a turntable and test the preamplifier. Select RIAA equalisation for both the left and right channels using the jumper links, then connect the RCA leads from the turntable to the input sockets on the preamplifier. The RCA outputs on the preamplifier go to either a power amplifier or the line input of a computer using a “Y” lead. The “Y” lead consists of a shielded stereo lead with RCA plugs at one end and a stereo 2.5mm jack plug at the other end. If you are connecting the preamp to an amplifier, then plug in headphones or use loudspeakers. If you are playing to a computer, make sure the line input level is turned up. You can set this in Windows XP via Start/Settings/ Control Panel/Sounds and Audio Devices/Audio, then selecting Volume in SC the Sound Recording section. siliconchip.com.au SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. 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Card expiry date: Signature_____________________________ SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Price Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE YOUR ORDER siliconchip.com.au P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Phone (02) 9939 3295 9am-5pm Mon-Fri Please have your credit card details ready OR Fax this form to (02) 9939 2648 with your credit card details 24 hours 7 days a week OR Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, August 2006 55 Australia 2097 08/06 SERVICEMAN'S LOG The dreaded black spot disease Black spots on a plasma display panel aren’t good at the best of times. This one really had us scratching our heads for a while but the explanation turned out to be quite simple. We had a Philips 42PF9954/68C Plasma (PDP) using a Fujitsu Hitachi high-definition display come in with the owner complaining of black spots. Sure enough, when we raised it up on our terrific new Panasonic display rig trolley – which can raise or lower the PDP (plasma display panel) to 45° or flat – you could clearly see lots of tiny black spots, which were in fact pixel dropouts. Pixel dropouts really are no longer 56 Silicon Chip an issue these days – at least, not until this set was dropped in. Anyway, we checked the unit out carefully and made sure that all the voltages were correct but could find no reason for this to have happened. It was then that we started to notice a few clues that pointed to possible owner abuse. For an item as new as this, you wouldn’t expect to see a lot of scratches around the mounting screws, plus it was very dusty and grubby. Items Covered This Month • Philips 42PF9954/68C plasma TV set (PDP) – FM242 chassis • Panasonic TX-80P300A TV set – EURO 7 chassis • • Funai Technicolor 212E VCR • LG Flatron RT-21FA31 (A) TV set – MC1019A chassis Panasonic TC68V86A TV set – MX4M chassis When we asked the client about this, he finally admitted that the unit had been fitted inside a bus and then taken right around Australia, including the siliconchip.com.au LTW Harsh Environment Connectors www.ltw-tech.com C-16 Line Multipin Circular Line D-Sub Multipin This is the picture on Mr Diesel’s Panasonic TV set after replacing the flyback transformer. It looks like an EHT or picture tube problem but the fault was quite different. back of “Woop Woop”. Under those circumstances, especially considering the horrendous vibration over all those corrugated dirt roads and the heat, the set was actually performing pretty well! The sick Panasonic Mr Diesel’s 2001 Panasonic TX-80P300A TV set (EURO 7 chassis) weighed 74kg, so I was delighted when he and his son carried it all the way onto my workshop bench. The set appeared to be completely dead but an initial inspection revealed nothing untoward, with no blown fuses or burnt components. I then measured the power coming into the set, tracing it all the way to relay RL801, before checking for voltages on the solenoid. I was surprised to see there was 7.5V reaching the relay drivers and in fact, I could toggle the relay using my ohmmeter as a driver. However, nothing much else was happening and one of the problems was that the U Board wasn’t switching the relay on. At this stage, I had to make up some sort of an estimate for the repair of this set. Knowing that the U Board (and DP Board) can give problems (they are the main microprocessor boards for control and sound), it was tempting to just quote for the U Board and leave it at that. However, in this case, I would have been wrong. Being a sensitive individual, I really didn’t want to do that without being sure and so I borrowed a U Board (with MPU IC1101 SDA6000) from another set. This substitute board produced more action, allowing the red standby LED D1051 to come on and off and the relays to click. However, there was still no EHT and the set switched back to Standby. This set does not lend itself to easy access, so it meant quite a bit of mechanical surgery to get the D Board completely out. Using an ohmmeter, I soon found a short on the 144V rail which was due to the 2SC5591PK line output transistor (Q551). So far so good but I now had to find out why this transistor had failed. I began by checking the tuning capacitors and D558 for leakage but these checks revealed nothing. It was only after I removed the flyback transformer T551 (ZTM77018A1) and used the shorted turns tester on siliconchip.com.au Multipin Circular RJ45 C-16 Style Miniature DIN Available in Australia from Altronic Distributors Agricultural • Industrial • Mining • Marine LTW connectors represent the ultimate in value and reliability for manufacturers of industrial equipment requiring waterproof connectivity. Available in IP66, 67 & 68 ratings for use in almost any environment. Altronic Distributors carry a range of products ex stock (see website for range available). Other LTW models available upon request. Minimum quantities apply. Sydney Melbourne Perth DISTRIBUTORS PTY. LTD. Phone: 1300 780 999 Web: www.altronics.com.au The Microbric Viper is a perfect entry point into robotics and programming, or the ideal compliment to your existing robotics line up! All modules are fully assembled, meaning there is no need for a hot soldering iron to build your robot. This makes the Microbric Viper perfect in an educational environment. The Microbric connection system means fully reusable modules can be put together and taken apart quickly. Microbric requires nothing more than the supplied screwdriver to assemble, making it possible to have an operating robot in less than one hour! The Viper is controlled by a BasicAtom.com microcontroller, which is programmed in ‘BASIC’, an easy language to learn the fundamentals of robotics programming. Remote Control Robot Bump Robot Available At August 2006 57 Serviceman’s Log – continued pins 9 and 10 that I discovered the real cause – the transformer was up the spout. The replacement parts arrived about a week later and I immediately fitted them. I then switched the set on, fully expecting it to be working again and only requiring some adjustments to the two focus controls and the screen potentiometers. Instead, I was horrified to find that not only did I have great difficulty in switching the set on (the remote wasn’t working) but all I could get was a weird picture that was small and out of focus (see photo). And no matter what I did, I couldn’t improve it. I was beginning to suspect the picture tube and yoke but was once again saved by having another working set. Swapping the complete chassis soon proved that it wasn’t that so I swapped over the CRT socket board (L) but it wasn’t that either. I then swapped over the entire defection D board but again drew a blank. By now, I could really feel my frustration level rising. I just couldn’t work out what could possibly be causing these symptoms, particularly the lack of focus. Surely this could only be an EHT problem? However, I had already replaced that entire section. 58 Silicon Chip Well, I persevered, swapping between the two chassis board by board in an effort to track the fault down. It wasn’t until I got to the main motherboard (A) that I finally managed to transfer the fault. None of its modules made any difference though, including the U Board. Well, because of the multitude of weird symptoms, I opted to replace the EEPROM IC1104. Bingo! – that was the cause of all the problems. IC1104 has ST24LC16B.1A45 written on it and the part number is listed as 24LC16B1PA45. The only problem was that the new IC arrived unprogrammed and gave an extremely bright uncontrollable raster that would probably quickly damage the new flyback transformer if left on. Well, what was I supposed to do now? I ordered an EEPROM read/ writer from Jaycar but there were some further checks to do before this piece of equipment arrived. First, I went through our pile of scrapped TV chassis looking for a Panasonic EEPROM that was similar to the one required. Eventually, I found one in what looked like an MD-1 chassis. Installing this in my chassis gave a reasonable picture but with a limited amount of control. However, I could at least get into the service menus and “Self Check” reported only six errors. Fortunately, having the service manual helped in setting up the EEPROM edit mode. As I quickly discovered, this is somewhat involved. You have to go into both Service Mode 1 and Service Mode 2 before entering the EEPROM Edit Mode. To do this, you must select Channel 99, set the OFF timer to 15, the Bass to maximum and the Treble to minimum, press the “F” button on the TV and set the volume to zero. The volume display must be ON while you simultaneously press the Volume Down on the TV and the Recall or Index button on the remote. To get to the next menu you have to scroll down to the last menu page of Service Mode 1 (SPL, GAIN) with the RED remote button and then press the HOLD key. You then press the RECALL button on the remote and if the menus haven’t timed out in the process you should have arrived at the EAROM Editor with a large table of addresses and data. The OPTION addresses are OE0 to OE7 and OE8 to OEF and you have to make sure that the data for each address is correct for your model in the table list in the service manual. In my case, I had five options that needed changing. You scroll with the coloured keys and channel up/down on the remote and change the data value with volume + and -. When the value is correct, you have to store it by pressing the STR button. You then exit the edit mode by turning the set off. In my case, I had to re-enter the menus several more times to get the geometry and grey scale correct for this specific set. It was at this stage that I suddenly realised that I had lost the sound. This was caused by dry joints on the DP Board (TVPA1727ZA) which is no longer available. The current revision is V5 which is printed on the edge of the board. The dry joints involve IC2510 – a 32 pin dual in-line surfacemounted IC – and a lot of feedthrough solder connections. This is fiddly detail work that I find difficult but necessity is the mother of invention. Anyway, that finally fixed all Mr Diesel’s problems but as you can appreciate, a job like this is extremely difficult to quote for without actually doing all the work first. siliconchip.com.au igBee Promi-ESD02 Short Range Promi-ESD01 Long Range OEM Bluetooth Modules Promi-ESD modules are embedded Serial Bluetooth products based on Bluetooth V1.1 Technology. Promi-ESD Series is designed for integration into user equipment. They use a built-in serial UART interface and communicate with other Bluetooth Devices. EZBee is a compact ZigBee single-board module which is compliant to the 2.45GHz Zigbee specification V1.0 of IEEE 802.15.4, With EZBee, users may enable Zigbee networks easily without extensive knowledge of the Zigbee protocol. EZBee is designed to be used as a serial RF module to a Host system. Typical Applications: Promi-DBS Evaluation Kit • • • • • • • RS232 Cable Replacement Wireless POS Systems M2M Communications Wireless Printing Phone and PDA Comms Healthcare equipment In car communications IN STOCK NOW! RFMA RF Modules Australia Low Power Wireless Connectivity Specialists Ironically, I found out later that you can obtain the EEPROM preprogrammed for less money than the empty one. The correct part number for the TX-80P300A is TVRJ2A021 which is no longer available but is substituted with TVRJ2A007 for the TC-68P22A. VCR formats In 1980, the VCR manufacturers were in a huge mess over which format standard to adopt – VHS, Beta or VC2000 – and the marketing wars were on for young and old. Suddenly, a new contender appeared with the compact CVC quarter inch (6.25mm) cassette. This lightweight portable (3.5kg) player came out of nowhere from a small company called Funai (F612VE) and sold for around $1500! It was marketed around the world under a variety of different brands and was sold with a variety of different accessories. The camera option was either a JVC GX-44E or Hitachi GP-41D and there was also a TV tuner. This upstart precipitated a new round of technology, including the Video 8 and VHS-C cassettes. The siliconchip.com.au CVC cassette format quickly lost out and you rarely even hear of it now 26 years later. When a good friend of mine passed away recently, his family was left with a complete CVC system, including one cassette on which a recording had been made. Hoping that this contained significant video coverage of my friend, they asked me to copy it onto DVD. This was going to be no mean feat as the recorder no longer worked properly. This particular model was called a Technicolor 212E and the last time I had seen one of these was well over 15 years ago. However, I was pleasantly surprised to discover a copy of the original Funai service manual buried in our archives. It had been supplied by Hanimex who were the local agents at that time. The recorder is well built and is easy to disassemble, apart from a couple of hidden screws on the righthand side control panel. The deck I was working on had no reel torque and consequently was chewing up tapes on play and stop when the loading motor unravelled and spilt the tape inside. Once the deck was out, it didn’t take EZBee-EK Evaluation Kit EZB-001 – Short Range EZB-100 – Long Range Typical Applications: • • • • • • • Wireless remote control Personal area networks Building automation Industrial control Sensor networks OEM equipment PC peripherals IN STOCK NOW! RF Modules Australia PO Box 1957, Launceston, TAS., 7250 Ph: 03-6331-6789 Fax: 03-6331-1243 Email: sales<at>rfmodules.com.au Web: rfmodules.com.au long to discover that the problem was caused by disintegrating rubber drive belts – in particular the reel belt which had broken into several lengths on the bottom of the unit. I thought that guessing the size of this belt would be a problem but was pleasantly surprised to discover that I still had the original parts in stock (“never throw anything out, it might come in handy” is my motto). However I wasn’t quite that lucky – my stock belt was also 26 years old and had also perished. However, it wasn’t too far gone for me to be able to measure it and order a generic one the same size. The other four belts were also ordered at the same time and when they arrived, I quickly fitted them and reassembled the deck. I then connected a DVD recorder to the AV outputs on the power supply and made quite a reasonable copy. In fact, I was quite impressed with the performance of this machine, considering it was built some 25 years ago. Recycling an LG A young lady recently phoned and asked me to come and pick up her LG August 2006 59 Serviceman’s Log – continued at the rear of the set, especially round the AV sockets. I suspected that the problem was an AV switching fault but it was too hard to fix in a poorly accessible dark corner in the house. The set had to go back to the workshop and once on the bench, I used a CRO to quickly trace the fault to the AV switching IC (IC3001, M51321P) on the H Board where all the AV inputs are. A new one fixed everything. Back to school Flatron RT-21FA31 (A) TV set. This set uses an MC1019A chassis and the unit in question was only a few years old. She didn’t want the set fixed, however. Instead, she wanted me to take it away and do whatever I wanted with it. The set was dead and she was recycling it the best way she knew. The cost of repairing it versus upgrading the set to an LCD or plasma set made it redundant. Well, the set was in good condition and looked the part. And it didn’t take me long to determine that it was dead (or rather pulsating) because the line output transistor (Q402, TT2140) was short circuit. Its replacement is part number OTR570200AA which can be substituted with a 2SD2627 or KSD5702. My only concern was what caused its early demise. First, I pulled the flyback transformer T401 out and checked for shorted turns – it measured OK so I figured it was probably OK. That’s the problem with a shorted turns tester – it’s not a conclusive test and often doesn’t pick up shorts in the EHT overwind diodes. Silicon Chip Binders H Each binder holds up to 12 issues H SILICON CHIP logo printed on spine & cover Price: $A12.95 plus $A5.50 p&p each. Available in Australia only. Buy five and get them postage free. 60 Silicon Chip It cost me an extra transistor before I woke up to the fact that it really did need a new flyback transformer as well (Part No. 6174V-6006E). My excuse is that I was seduced by the dry joints on the horizontal driver transformer and (incorrectly as it turned out) blamed these for the transistor failure. This fixed the fault but was it really worth it? The set is now only worth about $200 new and the trade cost of the parts alone was about $75, so selling it for about $100 won’t even pay for my labour, let alone give me a profit. It’s incredible but perfectly good technology is destined to become landfill in less than five years in ever increasing amounts. How is the planet going to filter out the dangerous chemicals before we eventually eat and drink the residue? The corroded Panasonic I was called out to a customer’s home to attend to a supposedly dead Panasonic TV. When I arrived, it looked like a fairly modern silver 68cm unit but when I checked the model, it was a TC68V86A which uses a fairly old MX4M chassis. The set wasn’t dead but was only showing a blue raster with no TV, AV1 or AV2 video. Instead, there was only AV sound even though every source was working! When I removed the back, I could see that the set had been corroded due to its proximity to the beach for most of its life. This corrosion was worse I was contracted for a service call to an NEC FS68T90 TV in a primary school classroom. The complaint was that the set wouldn’t start and I thought that the repair would be straightforward. Unfortunately, I arrived while the class was in full steam and I was as much a distracted by the kids and their antics as they were by me. The first thing I noticed was a little box marked “Video Commander” screwed to the top of the back shell of the cabinet. “What the heck is that?”, I thought. The next thing I noticed was that the power cord from the TV set was plugged into this box, which in turn was plugged into the mains wall socket. I unplugged the TV from the box and connected it directly to the wall socket, switched the TV on and it worked OK. Obviously, there was nothing wrong with the TV; it had to be the box. It took a little while before I understood what was happening here. The school had recently been upgraded and a computerised system had been installed which was controlled in the library. When a teacher wanted to show a particular video to a class, he/she would book that video in the library which would then route it into that classroom via the Video Commander at the time requested. It initially struck me that such a system was a little bit of overkill in terms of complexity and resources. Why not have individual VCRs and just borrow the tapes? On second thoughts, it’s probably an excellent scheme. There’s no chance of the tapes getting lost and the number of VCRs required is dramatically reduced, along with their maintenance requirements. Perhaps the “guvmint” really knows SC what it’s doing after all! siliconchip.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au PRODUCT SHOWCASE Altronics’ “Proart”: and you shall have music wherever you go The fact that the Proart home audio distribution system appears in the same issue as a major home theatre projector review is purely coincidental . . . but timely! For those thinking about installing a home theatre system, the Proart Audio Distribution System could be just what they are looking for, the perfect accompaniment. And for those who have never even considered a home theatre system but liked the idea of piping any types of audio signals anywhere around the home – in fact, a variety of different audio signals at the same time to a number of different rooms with complete control – this system is well worth a second (or third!) look. With many new homes these days being Cat5 “wired” for data during the building stage, maybe wiring for audio – controlled by a system such as this – should also be a high priority. And for commercial/industrial users, the Proart could also solve a lot of audio problems (eg, sound through a building). But we are getting a bit ahead of the game. First of all, what is the Proart Audio Distribution System? From Altronics (who also had a hand in the design), it’s a new and, we believe, quiteinnovative method of controlling and routing up to eight input sources to up to 12 speaker zones (rooms, if you like) or if you prefer, less stereo and/or surround sound zones. What’s more, it’s fully remote controllable, it connects together using Cat5 cable and RJ45 connectors and it’s delightfully easy to install and configure. Stacked for our photo, the A5024 12-channel amplifier (top) and the A5020 Matrix Control Unit below. Inset is one of the infrared remote control unit wall plates along with its controller. There are three components to the system (not including the eight audio program sources, which you can choose yourself to suit your requirements, anything from tuners to DVD, CD or even TV sound. You could even have different tuners feeding different radio stations). First is the A5024 multi-channel amplifier. Well, that’s probably a misnomer: this beast actually contains twelve independent 40W amplifier modules, which may be connected any way you wish (ie, 12 single (mono) rooms, 6 rooms with stereo, 1 room with 6-channel surround sound and 6 other rooms, etc etc). The amplifiers can also be oper- ated in bridge mode to achieve higher power – in fact, you could operate all in bridge mode to achieve three stereo amplifiers of 120W per channel capacity. As well as standard RCA socket input for each channel, there are RJ45 “bus” inputs for each channel with switches to select between the Continued on p70 STEPDOWN TRANSFORMERS 60VA to 3KVA encased toroids Harbuch Electronics Pty Ltd The back panel of the A5024 12-channel amplifier, shows what a busy beast it is! The sockets immediately below the RCA input sockets are for the buses. siliconchip.com.au 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 August 2006 69 Proart Audio Distribution System – continued two. What are the bus inputs for? Read on! Performance-wise, it’s no slouch: each amplifier has THD of <.005% (20Hz-20kHz), frequency response is within 0.4dB 10Hz-50kHz and it has better than 60dB crosstalk and 80dB hum and noise. It can be powered from 240V AC or 24V DC. That’s the amplifier – pretty impressive in its own right. But it’s when you team it up with the A5020 Matrix Control Unit that the goalposts move – right into the next field! Matrix controllers can basically connect any input to any output – in whatever combination you wish. The Proart A5020 will do this but it will do so much more. It’s used in conjunction with the A5026 wall plate to give total infrared remote control – not just of the signal program switching and volume, but will also allow other devices such as CD/DVD players, etc, in other rooms to be remotely controlled. Each channel has RCA inputs and outputs but, like the 12-channel amplifier, the controller also has RJ45 “buss” outputs which to link it to the same connectors on the amplifier or the wall plates. As well as being “receivers” for the remote control, the A5026 wallplate has pushbuttons for manual control. A LED display and indicators show the current volume setting and sig- PC-Bay LCD Information nal sources. The unit fits a standard electrical wall box and is wired with standard Cat5/RJ45 cable. In most cases, a single wallplate will adequately cover even a large room but if more wallplates are needed, they can be “daisy chained” (just like computer networks). There’s also a range of infrared accessories to suit the system – it’s best to refer to the Proart brochure (downloadable from http://www.altronics. com.au/download/Brochures/Audio/ A5020.pdf) OK, you can probably tell that we are impressed by the Proart Audio Distribution System. It’s not cheap – but it is significantly cheaper than anything else on the market (and we’re not convinced they will do the job as well). The A5020 Matrix Control Unit sells for $990, the A5024 12-channel amplifier $1099 and the A5026 remote control panels $199 each for two or more (and you’ll need more than two!). There’s also a package deal but there’s not a great deal of point talking about it because it costs exactly the same as the individual units! Dominion Electronics has available two new series of MX series LCD Digital Information Inserts. Made by Matrix Orbital, these are designed to fit into standard PC front-panel cutouts – single height in the case of a the MX200 series and double height for the MX400 series. They can be used to give information about the operation of the PC or can be used in place of a monitor. The MX200 offers a 20 x 2-line display, while the MX400 has a 20 x 4-line. Display colours are green on yellow, blue on cool white, white on blue or inverse yellow. The display draws 25mA; the backlight 150mA. They’re available with or without a 7-key keypad and a USB or serial (TTL) interface. The MX200 sells for $155.00 (+GST) while the MX400 is $212.00 (+GST). Contact: Contact: 174 Rowe St, Perth WA 6000 Tel: (08) 9428 2199 Fax: (08) 9428 2198 Website: www.altronics.com.au U13, 82 Reserve Rd, Artarmon NSW 2064 Tel: (02) 9906 6988 Fax: (02) 9906 7145 Website: www.dominion.net.au Altronics Distributors Dominion Electronics Pty Ltd Smartcal and TRIO Test & Measurement Solutions merge SmartCal and TRIO Test & Measurement Solutions announce their merger on 1st July 2006. The new company, TRIO Smartcal Pty Ltd offers a one-stop-shop for test equipment sales, service and calibration. Smartcal, Australia’s most experienced Tektronix service, repair and calibration providerwas formed by ex-employees of the Tektronix service department when Tektronix closed their Australian T&M office in 2001. Smartcal is also the authorized Calibration Provider for National Instruments and in addition offers repairs and calibration on many other leading brands such as Fluke and takes pride in its integrity and loyalty to its customers. TRIO was formed 40 years ago in 70 Silicon Chip Adelaide and has grown to be one of Australia’s premier national T&M distributors representing world-class suppliers such as Fluke, Yokogawa, LeCroy, Hameg and Rohde & Schwarz. TRIO T&M also has a manufacturing division and is Australia’s premier manufacturer of portable appliance testers. The new company offers a complete test and measurement solution, including pre- and post-sales advice, technical support, repair and calibration. TRIO Smartcal provides national geographic coverage with offices in Sydney, Brisbane, Adelaide and Melbourne. An interesting service is the custom R&D bench which can be rented on a daily basis when customers have a project but do not need to buy, or cannot afford to buy, a lot of performance test equipment such as spectrum analyzers, signal and arbitrary waveform generators, performance oscilloscopes etc. TRIO Smartcal can offer un-biased advice for users of older test equipment whether repair or replacement is the most economical course of action. This differs from organizations focused only on repair or sales where customers do not get this un-biased choice or advice. In most cases if replacement is chosen TRIO Smartcal will offer a trade-in allowance for the old test equipment. Contact: Trio Smartcal Pty Ltd 3 Byfield St. North Ryde NSW 2113 Tel: 1300 853 407 Fax: 1300 853 409 Website: www.triotest.com.au siliconchip.com.au And the winner is... A NOTE TO SILICON CHIP SUBSCRIBERS Your magazine address sheet shows when your current subscription expires. This month’s winner of one of these superb DSE 20MHz dualchannel ’scopes in the SILICON CHIP subscriptions promotion is: Glenn Collins of Wavell Heights, Qld. Check it out to see how many you still have. If your magazine has not turned up by the first week of the month, contact us at silchip<at>siliconchip.com.au Three new Eddystone boxes from Hammond Electronics Hammond Electronics, one of the world’s leading manufacturers of small diecast aluminium and plastic enclosures, purchased the tooling and intellectual property of the well-know Eddystone range from Marconi in 1998. The complete range of European and North American manufactured Hammond enclosures is now available from national, regional and local distributors throughout Australasia. Probably one of the best know brands in the small enclosure sector, the Eddystone range consists of nine sizes of thin siliconchip.com.au wall shallow lid general purpose die-cast aluminium enclosures and a further five variants fitted with a deep lid. Hammond’s Australian operation is a manufacturer in its own right. Hammond Electronics Pty has introduced a further three sizes to complement the original 14-strong family. Designed and manufactured only in Australia, the new sizes are 50 x 50 x 21, 92 x 92 x 38 and 125 x 125 x 53mm. In addition to serving the needs of the local market, the Australian manufactured enclosures are exported in large volumes to Hammond’s European operation. SC Contact: Hammond Electronics Pty Ltd GPO Box 812, Adelaide SA 5001 Tel: (08) 8235 0744 Fax: (08) 8356 3652 Website: www.hammondmfg.com August 2006 71 Ever wanted to be able to listen to the ‘unlistenable’ – sounds that are way beyond the range of normal human hearing? Like the supersonic whine of a gas leak, or the echo-location ‘chirps’ of bats? Here’s a low-cost project that will let you do just that. It’s a down-converter which shifts ultrasonic sound signals down into the frequency range where they can be heard (or recorded). by Jim Rowe ULTRASONIC EAVESDROP A FEW WEEKS AGO, I found myself watching a wildlife doco on TV in which naturalists were studying the behaviour of bats. They were using infrared lighting to photograph them and a down-converter so that they could hear and record the ultrasonic ‘chirps’ that the bats use for navigation in the dark – and often for tracking down their insect prey. My curiosity was aroused and I decided to ‘have a go’ at coming up with a low cost down-converter of my own. This project is the end result, presented so that other readers can indulge their curiosity as well. I won’t claim that the project has all kinds of uses, because it’s mainly going to be useful for listening to the ultrasonic sounds emitted by bats and one or two other nocturnal insect-eating creatures. But you should also be able to use it to track down the exact location of high-pressure gas leaks -- which apparently also produce an ultrasonic whistle or whine. You could even use it to make sure an ultrasonic dog whistle is working, if Fido seems to be ignoring it (perhaps his hearing has deteriorated like mine)! How it works Most of the sounds emitted by bats are in the frequency range from about 15kHz to 50kHz, with a few extending 72 Silicon Chip up to about 150kHz and a small number extending down below 10kHz. So most of them are above the range of human hearing, and some well above. (Young people can often hear up to about 18-20kHz but this upper limit generally falls as we grow older.) The idea of the eavesdropper is to shift the ultrasonic sounds down in frequency, so they fall within our comfortable hearing range. This is done by using the heterodyne principle, in much the same way as it’s used in many radio receivers. Or more accurately, in exactly the same way as it’s used in ‘direct conversion’ receivers: we mix the incoming ultrasonic signals with a continuous ultrasonic signal from a ‘local oscillator’. In the mixer the two signals heterodyne or ‘beat’ together, generating signals which correspond to the sum and difference of the two frequencies. The ‘sum’ signal will be very high in the ultrasonic range – and thus even more inaudible – but the ‘difference’ signal is easily arranged to be much lower in frequency and therefore in the audible (to humans!) range. You can see how this down-conversion system works from the block diagram in Fig.1. The ultrasonic sounds are picked up by a small electret siliconchip.com.au PPER microphone, which turns them into small ultrasonic electrical signals. This type of microphone has a frequency response which extends well up into the ultrasonic region. The signals are then passed through a preamplifier to boost them to a more useful amplitude (or level), where they can be passed into one input of a balanced mixer. The other input to the mixer is fed with a continuous ultrasonic signal produced by a tuneable ‘local oscillator’, so it can be varied in frequency from about 15kHz to 50kHz. As a result the output of the balanced mixer contains three main frequency components: the difference signals (FIN - FOSC) and (FOSC - FIN), and the sum signal (Fin + FOSC). The sum signal is obviously even higher in the ultrasonic range than FIN and FOSC, so it’s of no interest to us. We filter it out, anyway. But by adjusting the tuning of the local oscillator the difference signals can be placed down in the audible range, so all we have to do is feed them through an audio amplifier (via a volume control), before they can be either heard in a pair of headphones or sent to a tape or other recorder (even recorded on a computer hard disk or memory card for later analysis). What’s with the dish? Fig.1: the block diagram shows the various functional elements of the Ultrasonic Eavesdropper. siliconchip.com.au Used by itself, the electret microphone insert works – but not very well. To make it more effective, we concentrate the ultrasonic sound waves with a small, “somewhat” parabolic dish. As you may recall from previous SILICON CHIP projects, a parabolic dish reflects all the waves which strike it back to its focal point. With the miAugust 2006 73 74 Silicon Chip siliconchip.com.au 1nF 220k 10nF 4.7k 4 6 9 8 VR2 5k 8 470Ω 220k 1 5 6 IC3: LM833 8 O5-9 12 O0 O1 O2 O3 O5 O6 O7 O8 O9 1 5 6 9 11 3 2 4 7 IC2 4017B O4 10 CP1 Vss MR CP0 IC3a 470nF 2 3 PREAMP GAIN 180k 13 15 10 14 6.8k 7 14 Vdd ULTRASONIC EAVESDROPPER MIC INPUT CON1 47 µF 5 VR1 5k IC1b 11 OSCILLATOR FREQUENCY 1.2k MIC1 ELECTRET INSERT 2 IC1a 13 IC1d IC1c 16 4 IC3b 16k 10k 16k 120k 120k 7 22 µF 100nF 100nF 680Ω 100nF 1k +12V 4.7nF 11k 11k 30k 30k 100nF 1k 560Ω 470Ω 8 10 1.5k +12V 3 1k 14 MIXER BALANCE VR4 1 6 4.7nF 12 470Ω 4 5 10k λ LED1 1k IC4 MC1496 2 220Ω K A Fig.2: the circuit beats the “bat” frequency against the supersonic generator formed by IC1 and IC2. SC 2006 + 100nF 1 3 12 IC1: 4093B 100nF 4.7nF 4.7nF 1k 2x 3.3k 100 µF 100Ω A ZD1 K 2 VOLUME VR3 10k 3 2.2 µF 6 1 4 10 µF IC5 LM386N ZD1 12V 1W 220 µF A K 100Ω 7 8 5 10Ω 47nF 220 µF 2200 µF K A D1 1N4004 A K 1N4004 LED 12-15V DC INPUT STEREO PHONES CON2 RECORD OUT CON4 1k A K CON3 Fig.3: the entire project mounts on a single PC board, with the electret mic insert connected via an RCA socket on the left side. The sockets on the right connect power (12VDC), earphones and some form of audio recorder. We used IC sockets (as seen in the photo below) but these are not really necessary. crophone insert mounted at the focal point (or as close as we can guess!), pick-up becomes much more efficient and effective. This dish can be made from just about any material which will reflect sound waves – we used a laminated wood cereal or salad bowl, bought from a ‘bargain store’ for just a couple of dollars. It is about 155mm in diameter and about 39mm deep but this is not at all critical – a larger dish should be even better but would start to become unwieldy. A similar (hard) plastic or even stainless steel salad bowl could also be used. We said a moment ago that it was “somewhat” parabolic in shape – it has a flat bottom. This might not be technically ideal but it is good enough for our purposes – and certainly makes it a lot simpler to attach things to! You can work out the focal point of a parabola by formula (but it is complicated by the flat bottom), or you could line the bowl with aluminium foil and aim the bowl at the sun to enable you to get it spot on (as we did for the dishes used in our WiFry articles). Another way of finding the focal point would be to connect the mic insert to an audio amplifier and aim the dish at a single point sound source (such as a speaker connected siliconchip.com.au to an oscillator). Moving the microphone back and forward along the centre axis would reveal one point where the maximum signal was found. Having said all that, we found near enough (an educated guess) was good enough – but feel free to experiment with distances! We’ll look at mounting the dish and microphone a little later. The circuit Now let’s look at the circuit diagram (Fig.2) for a more detailed understanding of how it works. The ultrasonic sounds are picked up by the electret microphone insert, MIC1. The fairly small signals from MIC1 are fed in via CON1 and first amplified by IC3a, half of an LM833 dual low-noise op amp. It’s used here as a preamp with its gain variable between about 40 and 400, using trimpot VR2. This allows the project to be set up for either short or long range bat monitoring, and with bats having either loud or soft ‘chirping’ (they do vary, between species). After amplification, the signals are passed through IC3b, the ‘other half’ of the LM833, connected as a unity-gain August 2006 75 The completed PC board screwed to the lid of the UB-3 box, which becomes the base. Actually, this photo is a tad premature in the assembly sequence because you need to screw the lid to the timberwork, then fit the PC board to the lid. buffer to provide a low impedance source feeding the mixer IC4, via a 1kW series resistor. The ultrasonic signal used for our ‘local oscillator’ is generated using IC1 and IC2. This signal (a) needs to be tuneable over a fairly wide frequency range; (b) should be reasonably low in harmonic content and (c) should also be fairly constant in amplitude. However, this combination of qualities is not easy to produce using conventional audio oscillator circuits. So we generate it in a slightly unusual fashion. Gates IC1a, IC1b & IC1d are used as a relaxation-type oscillator, producing a square wave clock signal which is variable between 150kHz and 500kHz using pot VR1. This clock signal is buffered by gate IC1c and fed into the clock input of IC2, a 4017B Johnson-type decade counter. This IC therefore counts the clock signals so that its 10 outputs, O0 - O9, switch high in turn, on a continuous cyclic basis. These outputs are used to drive a simple digital to analog converter (DAC) using a set of resistors. While it may appear that output O7 is not used, it is – its “infinite value” resistor (ie, open circuit!) actually sets the zero point. The values of the resistors are carefully chosen so that as the outputs of IC2 go high in turn, a 10-sample approximation of a sinewave is developed across the output (ie, the 680W resistor between pins 10 and 8 of IC4). The 4.7nF capacitor which is also across the output provides a measure of low-pass filtering and further ‘smoothing’ of Here you can see how the plastic case needs to be drilled and slotted . . . 76 Silicon Chip the sinewave. The result of this simple digital waveform synthesis is a fairly smooth sinewave signal of reasonably constant amplitude, with a frequency exactly one tenth that of the clock signal from IC1. So as the clock signal is varied between 150 and 500kHz via VR1, the ‘local oscillator’ sinewave signal at the pin 10 input of IC4 is varied between 15kHz and 50kHz. IC4 is an MC1496 double-balanced mixer, expressly designed for this kind of use. When we feed our amplified ultrasonic sound signal into its pin 1 input and our local oscillator signal into its pin 10 input, it performs analog multiplication between them and provides the corresponding sum and difference frequency signals at its outputs (pins 6 and 12, which are simply dual polarity outputs). By the way, the mixer strictly only produces just the sum and difference signals at its outputs when it is carefully balanced using trimpot VR4. If it is not truly balanced, both of the input signals can also be present in the outputs – although this is not a major problem here because both of these input signals are inaudible. All the same, it’s a good idea to have the mixer reasonably close to balance, to reduce distortion in the audio amplifier. We’ll explain how to do this later. . . . so that the PC board is an easy fit. Again, the lid is screwed to the handle before the board is placed inside the box. siliconchip.com.au As you can see in this project we take the mixer output signal from pin 6 of IC4 and then pass it through a simple low pass filter using the 1kW series resistor and 4.7nF capacitor (across volume control VR3). This filtering attenuates the ‘sum’ frequency components quite significantly, leaving mainly just the audible ‘difference’ components that represent the downshifted version of our ultrasonic sound signals. We then pass these through audio amplifier IC5, after adjusting their volume level via pot VR3. The amplified output of IC5 is used to drive a standard pair of stereo headphones via CON4 and/ or an audio recorder via line-level output CON2. The complete circuit is designed to operate from almost any source of 12-15V DC, which is fed in via CON3 and can come from either a small AC plugpack supply or a nominal 12V battery such as that in a car or motorcycle. The total current drain is less than 35mA, so you could also run it from a pair of 6V lantern batteries connected in series or even a pack of eight ‘C’ cells. Zener diode ZD1 limits the voltage which can be fed to ICs1-3, while LED1 is an indicator that power is applied. Construction All of the Eavesdropper circuitry is mounted on a single PC board, measuring only 122 x 57mm and coded 01208061. As you can see the board has rounded cutouts at each corner so it can be mounted snugly inside a standard plastic utility box measuring 130 x 68 x 44mm. Microphone input socket CON1 is mounted on the lefthand end of the board, while the DC input, headphone output and recording output connectors are all mounted on the right-hand end. The local oscillator ‘tuning’ pot VR1, power LED1 and volume control pot VR3 are all mounted along the front side for easy accessibility. Begin construction by checking the PC board for any etching problems or undrilled holes and fixing these before you proceed. Then it’s a good idea to fit the various connectors (CON1-CON4), as these sometimes require a small The “gun” assembly immediately before the UB-3 case lid is secured. You can clearly see the way that the piece of coat hanger wire which supports the electret microphone is attached. amount of fiddling and board hole enlargement. There is only one wire link to be fitted to the board, so I suggest you fit this next to make sure it isn’t forgotten. It’s located just behind CON4, at lower right as viewed in the PC board overlay diagram. Next fit the various fixed resistors, taking care to fit each one in its correct position. These can be followed by trimpots VR2 and VR4, making sure you don’t swap them around. The 5kW trimpot is VR2, while the 1kW trimpot is VR4. Don’t fit the two larger pots at this stage, though – they’re best fitted later. Now you can fit the capacitors, starting with the two 100nF multilayer monolithics (near IC1 and IC2) and then progressing through the small MKT caps, the 2.2mF tag tantalum electrolytic (just to the front of IC5) and then the other electrolytics. Remember that all the electrolytics are polarised, so make sure you orient them correctly (as shown in Fig.3, the PC board overlay diagram). After these you can fit the semiconductors, starting with diode D1 and zener diode ZD1 – again make sure you don’t swap these accidentally and that they are both fitted with the correct orientation as shown in the overlay diagram and Fig.4: use this diagram in conjunction with the photo above to work out which bit goes where! siliconchip.com.au August 2006 77 photos. Then fit the ICs, preferably in reverse numbered order (ie, IC5 first, then IC4, working your way back to IC2 and IC1). Even though we did, there is no need to fit any of the ICs in sockets unless you wish to. All five ICs must be oriented as shown. If you are soldering IC2 and IC1 directly into the board, take care to protect them from the possibility of electrostatic damage. Use an earthed soldering iron, earth yourself if possible (or at least discharge yourself before handling the ICs) and solder the supply pins of the ICs first (pins 7 and 14 on IC1, pins 8 and 16 on IC2) to enable their internal protection circuitry as early as possible. After the ICs are all in position, it’s time to fit power LED1. This is fitted to the board vertically to begin with, with its longer anode lead to the right and both leads soldered to their pads underneath with the LED’s body about 18mm above the board. Then using a pair of needle-nose pliers or similar, bend both leads forward by 90°, 12mm above the board. This will position the LED facing forward and ready to protrude through the matching hole in the box, after final assembly. The last two components to mount on the board are control pots VR1 and VR3, which are both fitted along the front of the board on either side of LED1. You may need to cut the pot spindles to about 10-12mm long before they’re fitted, if they’re not already this length. Make sure you fit Fig.5: hole drilling diagram for a UB-3 plastic box. 78 Silicon Chip siliconchip.com.au the 5kW linear (B) pot as VR1, and the 10kW log (A) pot as VR3, as shown in the overlay diagram. Your Eavesdropper board should now be complete and ready to be fitted to the lid of the UB3 box, which is used here as the base. But before doing this, you may need to prepare both the lid and the box itself, by drilling and cutting the various holes that are needed for mounting, assembly and access to the various connectors and controls. The location and dimensions of all of these holes are shown in the drilling diagram (Fig.5), so you shouldn’t have any problems if you use this as a guide. The hardware It would also be a good idea at this stage to make the Eavesdropper’s wooden ‘handle’ and attach to its front the small dish we mentioned earlier. The dish is simply attached to the front of the wooden handle using a couple of 15mm long self-tapping screws, passing through 3mm holes drilled in the centre of the bowl. Two further 3mm holes were drilled just above these mounting holes to allow the mic support ‘bracket’ and its shielded lead to pass through. The mic support bracket was bent up from a 200mm length of 2.2mm diameter steel wire, salvaged from a coat hanger. After straightening and cutting to length, the wire was bent into a small loop at one end (around the shank of a 4mm twist drill). Then the straight section of wire was passed through the matching hole in the back of the bowl, and the loop end attached to the top of the wooden handle about 45mm behind the bowl using a 15mm long woodscrew, with a small flat washer under the screw head. The front end of the bracket was then bent around and downwards in an open ‘J’ shape, about 20mm in diameter, so the end was aligned very closely with the centre axis of the bowl and about 65mm in front of the bowl’s inside centre – corresponding to an approximation of this bowl’s likely ‘focus’ as an ultrasonic reflector. Then the mini electret mic insert was cemented to the side of the wire’s end using epoxy cement, with its ‘front’ facing the centre of the bowl (ie, it looks backwards, not forwards). After the epoxy cement has cured, solder the wires at one end of a 300mm length of light duty, screened microphone cable to the mic insert connection pads, with the cable screen wires connected to the insert’s earthy/case pad and the inner wire to the other ‘+’ pad. This is a slightly tricky job, as the pads are very small and closely spaced. So take your time, and take care not to overheat the mic insert in particular. If you’re new to soldering, it might surprise you to find that a hot, well-tinned iron poses much less danger than a cooler iron. The solder job is completed much more quickly – before the insert has had a chance to realise it’s getting hot! It’s also a good idea to connect the cable screen to the wire support bracket just near the mic using a short length of fine tinned copper wire, to minimise hum pickup. The free end of the mic cable is then passed back through the remaining hole in the centre of the bowl and fitted with a metal-shelled RCA plug at the other end ready to plug into the Eavesdropper. To prevent the cable from flapping around it can be fastened to the mic supporting wire using three short siliconchip.com.au Parts List – Ultrasonic Eavesdropper 1 1 2 1 1 1 1 1 4 4 8 2 PC board, code 01208061, 122 x 57mm Plastic utility box, UB3 size (130 x 68 x 44mm) RCA socket, PC-mount (CON1, CON2) 2.5mm DC socket, PC-mount (CON3) 3.5mm stereo socket, PC-mount (CON4) Electret mic insert, miniature type 300mm length of screened mic cable RCA plug, metal screened type 10mm long M3 machine screws, countersink head M3 star lockwashers M3 nuts Small control knobs (for VR1 and VR3) Semiconductors 1 4093B quad Schmitt NAND gate (IC1) 1 4017B decade counter (IC2) 1 LM833 dual low noise op amp (IC3) 1 MC1496 double balanced mixer (IC4) 1 LM386N audio amplifier (IC5) 1 12V 1W zener diode (ZD1) 1 3mm green LED (LED1) 1 1N4004 1A diode (D1) Capacitors 1 2200mF 16V RB electrolytic 2 220mF 16V RB electrolytic 1 100mF 16V RB electrolytic 1 47mF 16V RB electrolytic 1 22mF 16V RB electrolytic 1 10mF 16V RB electrolytic 1 2.2mF 35V TAG tantalum 1 470nF MKT metallised polyester 5 100nF MKT metallised polyester 2 100nF multilayer monolithic 1 47nF MKT metallised polyester 1 10nF MKT metallised polyester 4 4.7nF MKT metallised polyester 1 1nF MKT metallised polyester Resistors (0.25W 1%) 2 220kW 1 180kW 2 120kW 2 30kW 2 16kW 2 11kW 2 10kW 1 6.8kW 1 4.7kW 2 3.3kW 1 1.5kW 1 1.2kW 5 1kW 1 680W 1 560W 3 470W 1 220W 2 100W 1 10W 1 5kW linear pot, 16mm or 24mm PC-mount (VR1) 1 5kW mini trimpot, horizontal PC-mount (VR2) 1 10kW log pot, 16mm or 24mm PC-mount (VR3) 1 1kW mini trimpot, horizontal PC-mount (VR4) lengths of ‘gaffer’ tape (visible in the photos) wrapped around them both. At this stage, we gave the whole assembly a couple of coats of matte black spray paint. It looks 100% better than leaving it “au naturel”, which looks like a wooden salad bowl screwed to a piece of timber . . . If you do this, don’t forget to completely cover the electret mic insert in adhesive tape to stop it getting painted. Masking tape is preferable because ordinary adhesive tape can be a real pest to remove! Once the handle-dish-mic assembly is complete, you August 2006 79 01208061 Fig.6 (above): the same-size PC board pattern, while below, (Fig 7) is the same-size front panel artwork. We simply laminated and glued the paper label to the box, leaving about a 2mm border around the edge. can attach the Eavesdropper’s lid/base plate to the top rear of the wooden handle using a couple of 15mm long woodscrews through the two 3mm holes in the centre. As you can see the lid is orientated at right angles to the handle axis, and centred over it. With the box lid attached to the handle, you can fit the Eavesdropper’s finished PC board assembly to the lid. It’s attached using four 10mm long M3 machine screws with countersink heads, passed up from below and each then fitted with a star lockwasher and M3 nut. These nuts act as spacers, so the screws and nuts should be firmly tightened before the board assembly is fitted. Then when it is in position, four further nuts are used to hold it in place. Checkout and adjustment When the PC board assembly is fixed in place, it’s time to fire up the Eavesdropper and give it a quick functional checkout. Set both of the main control pots to roughly their midrange positions and also set both trimpots to their midrange positions using a small screwdriver or alignment tool. Then plug the mic cable into CON1, a pair of standard stereo headphones into CON4 (but don’t put them on yet, just in case something is Resistor Colour Codes o o o o o o o o o o o o o o o o o o o o No. 2 1 2 2 2 2 2 1 1 1 1 1 5 1 1 3 1 2 1 80 Silicon Chip Value 220kW 180kW 120kW 30kW 16kW 11kW 10kW 6.8kW 4.7kW 3.3kW 1.5kW 1.2kW 1kW 680W 560W 470W 220W 100W 10W 4-Band Code (1%) red red yellow brown brown grey yellow brown brown red yellow brown orange black orange brown brown blue orange brown brown brown orange brown brown black orange brown blue grey red brown yellow purple red brown orange orange red brown brown green red brown brown red red brown brown black red brown blue grey brown brown green blue brown brown yellow purple brown brown red red brown brown brown black brown brown brown black black gold 5-Band Code (1%) red red black orange brown brown grey black orange brown brown red black orange brown orange black black red brown brown blue black red brown brown brown black red brown brown black black red brown blue grey black brown brown yellow purple black brown brown orange orange black brown brown brown green black brown brown brown red black brown brown brown black black brown brown blue grey black black brown green blue black black brown yellow purple black black brown red red black black brown brown black black black brown brown black black gold brown siliconchip.com.au Two views looking for’ard and aft. If you paint the whole shebang black, like we did, make sure you wrap a piece of masking tape around the microphone insert first. They don’t like being covered in paint! wrong!) and the cable from your 12V battery or plug pack into CON3. Power LED1 should immediately light up, to show that the circuit is operating. If the LED doesn’t light, this will probably be because one of three components is fitted to the board with reversed polarity: LED1 itself, D1 or ZD1. Either that or the plug on your DC input cable is wired with reversed polarity. With your multimeter you can check the voltage between the anode of D1 and the board’s ground – it should be the same as the incoming DC. Similarly the voltage at the cathode of D1 should Capacitor Codes Value 470nF 100nF 47nF 10nF 4.7nF 1nF μF Code 0.47µF 0.1µF .047µF .01µF .0047µF .001µF siliconchip.com.au EIA Code 474 104 473 103 472 102 IEC Code 470n 100n 47n 10n 4n7 1n0 be only 0.6V lower, while that at the cathode end of ZD1 should be a little lower again. You should also be able to measure the same voltage at pin 14 of IC1, pin 16 of IC2 and pin 8 of IC3. Similarly at pin 6 of IC5 you should find the same voltage as you measured at the cathode of D1. Listen to the headphones without actually putting them on. If they are not shrieking, place the headphones on your ears and you should hear a small amount of noise and/or hum. If you turn up volume control pot VR3, this noise should increase a little, showing that the audio section of the circuit is working correctly. Now try returning VR3 to its midrange position and adjusting ‘tuning’ pot VR1 up or down. You may hear a faint heterodyne ‘whistle’ as you tune through one position in the tuning range. This is probably due to the mic preamp picking up a small amount of RF from a local AM radio station, which then heterodynes with the Eavesdropper’s local oscillator or one of its harmonics. This is not likely to interfere with the Eavesdropper’s normal operation but if nothing else it shows that the Eavesdropper’s local oscillator, ultrasonic preamp and mixer sections are all working. If all seems well at this stage, your Eavesdropper is probably working correctly and all that remains to be done before final box assembly is to set the mixer balance trimpot VR4 to the correct position. Got a ’scope? Mixer balance adjustment is easiest with an oscilloscope but if you don’t have access to one, you don’t really have to concern yourself about it; simply leave VR4 set to its midrange position, which is very likely to be ‘near enough’ for most purposes. If you do have access to a scope and you want to set the mixer for the best possible performance, the adjustment is quite easy. All you need to do is monitor the level of the Eavesdropper’s ‘local oscillator’ signal appearing at pin 6 of IC4 with your ’scope, while adjustAugust 2006 81 Here’s what the finished project looks like, ready to use (all you need is a 12V battery pack!). The headphones can be just about anything – including the bargain shop $2 cheapies! ing VR4 with a small screwdriver. At either end of the trimpot’s range the signal will increase in level, while it will pass through a minimum or ‘null’ somewhere near the middle of the range. The correct setting for VR4 is right at the centre of this null – this corresponds to the mixer being balanced. Final assembly The final assembly step is to fit the box itself down over the PC board assembly, as a protective cover. This is done by inverting the box and tilting it an angle of about 45° so that it can be offered up to the PC board with the control pot spindles and LED1 entering their matching holes on the box ‘front side’ from the inside. Then the box is moved towards the mic and reflector bowl, gradually tilting it down so the undrilled long side swings down outside the 220mF electrolytic and the other components along the rear of the board. The slots at each end of the box will allow the ends to clear the protruding sleeves of RCA connectors CON1 and CON2. When the box has been juggled into position, it can be attached to the lid/ base using the four small self-tapping screws supplied with it. Then the control pots can be fitted with their nuts, which can also be lightly tightened to help support the pots when the Eavesdropper is being used. After this you can fit the knobs, and your Eavesdropper should be ready for use. Using it! The top trace of this ’scope shot shows the synthesised sine wave coming from the ladder network of IC2. The lower (blue) trace shows the output at pin 6 of IC4. The very low mean voltage measurement of 5.38mV shows that the modulator is balanced. 82 Silicon Chip This is also very straightforward. You use ‘tuning’ pot VR1 to search for ultrasonic sounds over the Eavesdropper’s range and then when you find one the same control is used to shift the sounds down to a convenient frequency for listening or recording. Volume pot VR3 is used simply to adjust the output audio to a convenient level. You’ll probably find the Eavesdropper sensitive enough to pick up bat chirps, etc with the preamp gain trimpot VR2 left in its suggested midrange position. However if you want to have the highest possible sensitivity, VR2 can be turned up to its fully clockwise position. Happy bat tracking! SC siliconchip.com.au Making sense of all the information Part 2: by Julian Edgar Race Car Data Logging This data screen shows the car, a Formula Ford, half way through Turn 4 at the Philip Island circuit on Lap 5. (The map in the bottom right-hand corner shows this location.) From top to bottom, five parameters have been chosen for graphing. These are: engine speed (4814 RPM at this point); corrected speed (78.8km/h); throttle position (85.3 per cent); longitudinal acceleration (0.23g); and steering angle (1.7 degrees). In addition to the graphed information, the other logged parameters are also available in table form. They include engine oil pressure (32.63 psi); lateral acceleration -1.31g; suspension heights (front-left: -4.9mm, front-right: 11.3mm, rear-left: 11.9mm, rear-right: -1.1mm) and so on. Any of these parameters can be selected for graphing. By moving the vertical blue cursor to the left or right, the status of the car at any position on the track can be displayed. siliconchip.com.au siliconchip.com.au Staying on Turn 4, the race engineer can zoom in on the graphed data so that instead of looking at one complete lap, he or she is looking at only 10 seconds or so. The engineer can then overlay the logged data from another lap – here this other data is from Lap 1 and shown in black. This indicates that the driver on Lap 1 drove quite differently; exiting Turn 4 he was 12km/h quicker and the mid-corner steering input was dramatically changed. Note the throttle use – a racing car spends most of its time at either zero or 100 per cent throttle. The data in the right-hand column can be configured to show the absolute numbers or the relative difference between them; the latter has been done here. August ugust 2006 83 2006 83 A L ast month we looked at the data that is now routinely logged from sensors in racing cars. But when the car has come into the pits, what does the race engineer do with the logged information? It’s interpretation, rather than collection of information which is of the utmost importance in improving lap times. And this is where data analysis software like MoTeC’s i2 is used. When a drag run, such as that shown opposite, can be over in under five seconds, having the ability to carefully and slowly play back data log records is a huge advantage. The first stage in analysing the data is to put it into a frame of reference. It’s no good simply knowing that for Video footage can be synchronised with the data as it is played back real time, allowing observation of the driver or even such aspects as suspension deflection or anti-roll bar behaviour. Data can be logged to either a digital dash or the existing programmable engine management unit. example the peak engine speed was 6354 RPM and at one stage the car was travelling at 217.9km/h. That frame of reference is provided by the track map. Using the data collected by the lateral accelerometer and speed sensor or longitudinal accelerometer, the software is able to construct a virtual track map. The different sections of the track can then be automatically or manually Any of the logged parameters can be displayed in a ‘gauge’ format. The gauges are user-definable and can comprise circular bargraphs, traditional gauges with pointers, bar graphs, or on/off status blocks. In addition, a graphic showing the steering wheel position can be added and the track map can be used to show the location of the car when the data was collected. As with the graphing described above, when the position of the car on the track is altered, the gauges also change to show what is occurring. An animation function is also available where the car automatically ‘drives’ around the track, the gauges reflecting the changing status as it does so. This animation can occur at actual car speed or anywhere from 0.1 to 100 times real speed. More than one lap can be displayed simultaneously, with the second lap’s data displayed with black needles, bars and steering wheel. In addition to displaying the logged parameters, the MoTeC i2 software can also calculate data from the logged information. It does this by using maths expressions either supplied in the software or added by the user. For example, Oversteer (ie, the car yawing because the rear of the car is sliding laterally) is calculated using the following expression: Oversteer (rad) = smooth(choose(‘Corr Speed’[km/h]<50, 0, sgn(‘G Force Lat[m/s/s])*((‘Vehicle Wheelbase’[m]*’G Force Lat[m/s/s]/sqr(‘Corr Speed’[m/s])) – sgn(stat_mean(‘Steered Angle’[rad]*’G Force Lat’[m/s/s]))*’Steered angle’[rad])), 0.2) This calculated data can then be graphed along with the logged data. For example, here mid-corner the car is showing a calculated -3.9° of oversteer with a measured steering angle of 7.8°, a speed of 75.5km/h and a throttle position of 49.7%. 84 Silicon Chip siliconchip.com.au labelled (eg, “Turn 1” and “Straight 4-5”), allowing the analysis of data to proceed, based on where on the track the car was at the time. Other Functions In addition to the screens shown here, the i2 software can: • Draw scatter graphs (for example, graphing brake pressure versus front/rear brake bias - a technique that shows if the dual master cylinder brake pedal mechanism is flexing); • Correlate imported video imagery with the movement of the car around the track (in addition to showing the driver in action, video cameras can be used to examine suspension arm flexing and adjustable anti-roll bar behaviour); • Draw histograms for any of the logged parameters (eg showing the time the engine spends at different revs at full throttle, allowing optimisation of the shape of the engine power curve for that track). Conclusion The days of the driver down-changing too early, overreving the engine and then blaming something else for the engine failure are well and truly gone. In fact, one can almost feel pity for the driver who has every single one of their driving actions analysed in such detail! However, to be competitive in any high level motor sport, logging and analysis software has become vital. Another calculated value is damper (shock absorber) velocity expressed, in mm/s. This is calculated by the software on the basis of damper position and time and is most usually displayed in histogram form. The histogram bars correspond to 10 mm/s increments and both bump and rebound velocities are shown. A division between high speed and low speed damper movements is set that matches the damper valving characteristics (eg, 25 mm/s) and then analysis is possible of the proportion of time each damper spends moving at the different velocities in both low speed and high-speed bump and rebound. Specialist race car engineers suggest that symmetrical suspension damper velocity histograms (as here) show the correct bump and rebound damper settings are being used. This information is impossible to collect and view without sophisticated data logging and analysis software. siliconchip.com.au Data is logged and later analysed in all racing cars. Making sense of the collected information is the task of the race car engineer working with a dedicated analysis software package. The MoTeC I2 software shown here is available as a free download from http://software.motec.com.au/release/ The software comes with sample logs. MoTeC Pty Ltd. Phone: (03) 9761 5050. Website: www.motec.com The previous displays show a circuit racing car but data analysis is equally as important with a drag car. This screen grab shows data from a drag racing car at the Willowbank track in Queensland. Engine RPM and temperatures of the eight exhausts are shown on the graphs, while the righthand column again shows other data that was logged. This includes a longitudinal acceleration of over 4g(!), a supercharger boost pressure of 36 psi and a fuel flow of just under 44 US gallons/minute. (Note the facility of the software to mix and match units; purists may hate it but it’s the way of the racing world.) At this stage in the run wheel speed was only 33.5km/h; just over five seconds SC later it was 446km/h! August 2006 85 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ Multi-Throttle Control Are you into PC flight simulators? Find the control your typical controllers give you just a bit less than satisfying? Take a step up: add this very simple multithrottle controller and start flying with the big boys . . . T HIS PROJECT SHOWS how to construct a “bare bones” throttle controller for up to four engines. It is essentially a 4-axis, 4-switch analog controller, which plugs into a standard PC games port or can be expanded for those modern computers without such, to connect via a USB port. 90 Silicon Chip Make no mistake, Flight Sims (FS) and many Flight Combat Games (FCG) are complex software. You’ll typically learn to master them by throttling all engines (assuming a multi-engine plane!) by the same By Robert Gott amount at the same time. But as any pilot will tell you, that is simply not realistic. You need to be able to control the engines individually. Before we proceed further, a few words about controlling Flight Simulators are appropriate. A twist-handle USB joystick (4 axis – Aileron, Pitch, siliconchip.com.au Rudder & Throttle) is absolutely essential even for the beginner. Taxiing, take-offs and landings are pretty miserable without proper rudder control on the joystick. Don’t be tempted to buy cheap basic joysticks. You’ll regret it! Common good brands are Microsoft, CH, Saitek and Logitech. All of these now use the USB port. Assuming one has mastered the basics of flying using one throttle control that varies all engines’ RPM simultaneously, it’s time to now proceed to individual throttle control. Unfortunately, though, that control is not available on typical joysticks. That’s where this project comes in. It allows the “pilot” (you!) to vary the individual engine speed (measured in revolutions per minute or RPM) using Microsoft’s proprietary Control Panel settings in Windows. It would be wonderful if Microsoft would embody say eight or sixteen arbitrary “axis” and the same number of “buttons” in their next incarnation of Windows but for the moment 4 + 4 is the best available. Proprietary Throttle Quadrants such as CH USB 300-133 (shown above) use their own software but the cost is almost as high as the planes fly – circa US$150! With this project, we will achieve a modicum of reasonable results – but much cheaper. In fact, we believe it should cost no If you have the readies, this commercial throttle unit (CH USB 300-133) is regarded as one of the best around. Ours is just a tad simpler and a whole lot less expensive! more than about $25 or so: eight dollars for the four pots, a similar amount for the four switches and the balance for a box to put it all in. You’ll also need a multi-way cable with D15 connector but these can often be sourced from the junk box. OK, if you want to go all out and add knobs and a fancy label, you might stretch it to $25 – but not much more. The games Many of the older excellent games like the renowned “European Air Wars” by Microprose, “Battle of Britain” and “Red Baron 3D” by Sierra will not now install or run properly in Windows XP Pro, the author’s O.S. Sometimes a game will run in Windows “Compatibility” mode. (Right click desktop games icon>PROPERT IES>COMPATIBILY>follow prompts.) Other software called “Wrappers” try to emulate the original game playing software, not very successfully in the author’s experience. The list, which is by no means exhaustive, gives some hints and where this project will work, the author has personally tested the games using Multi-Throttle. PC Hardware and software. My PC is a four-year-old AMD for PC Flight Sims siliconchip.com.au August 2006 91 S1 ENGINE 1 100k LIN S2 ENGINE 2 100k LIN LIGHT GREEN 8 7 GREEN 6 5 PINK 4 MUSTARD 3 2 RED 1 15 14 13 BROWN/ BLACK BLACK 12 11 Construction GREY 10 9 VIOLET S3 ENGINE 3 100k LIN S4 ENGINE 4 100k LIN PC GAMES PORT (D15 PLUG) BROWN SC 2006 FLIGHT SIM MULTI THROTTLE controller Control up to four engines on a multi-engine flight sim plane. It plugs into your PC’s games port (or USB port via a USB adaptor) XP1800+, with 768MB RAM, 64MB GF3 Ti 200 AGP with games port, USB 1.1 and USB 2.0 sockets. The joystick is a Microsoft Sidewinder Precision Pro USB (Twist stick rudder control) run- ics (no separate graphics card) may struggle to play the named games anywhere near fully optioned. Modern PCs are better, but even Celeron and Sempron PCs with integrated graphics may use main swap memory and struggle similarly with the latest FS. To be realistic any PC older than a PentiumII 350MHz would not do justice to many, if any, of the games listed. ning Windows XP Pro with SP1 and DirectX (9c). The multi-throttle unit has NOT been tested with Windows 98SE but the Joystick configuration in Control Panel may work. Note: Older PCs with integral graph- There’s not much to this – no PC board, no difficult wiring. That’s mainly because there are few “components” as such – just the four switches and four pots wired to the D15 connector. Mount the hardware first because the wiring simply connects between it. Any plastic box of 130(W) x 70(D) x 45mm(H) or larger will suffice. Position the circular potentiometers and switches on the lid allowing for the size of chosen knobs and enough clearance for your fingers. Mark out and drill appropriate holes, four each for the pots and switches. Drill one hole in the preferred end of the box for the 15 core cable. It’s best to secure the cable with a cable clamp so you’ll need an extra hole for this. If you normally use a joystick with your right hand, the controller Parts List: Flight Sim Multi Throttle 1 ABS box, approx. 130 x 70 x 45mm 4 100kW linear pots 4 knobs to suit with index lines or pointers. 4 SPST toggle switches, (low voltage) 1 plastic cable clamp 1 10mm M3 screw, washer and nut 1 1.8m D15 male to female game cable extension. (eg, Altronics P1765) (or 2m D15 PC joystick extension cable (eg Maplin* TA50E <at> £4.99) 1 D15 to USB Converter if required. (eg, Maplin* UA22Y <at> £8.00) Possible alternative suppliers: www.wyntec.com.au or www.trianglecables.com *(www.maplin.co.uk) 92 Silicon Chip Here’s a view inside the “opened out” controller siliconchip.com.au Flight Simulators and Combat Flying Games GAME/Publisher Windows Version API: Direct X OpenGL, 3DFX CPU: Pentium or Playable equiv AMD MultiEngines 2 or 4 Tested With Multi-Throttle? Comments FS 2004 Microsoft XP DX 9.0c P4 or AMD64 2 and 4 No but should be OK Should work OK. Needs latest mid price graphics card minimum. FS 2002 Microsoft 98 ME XP DX 8.0a P4 2 and 4 Yes Needs good graphics card, plenty of memory. Wings of War Gathering 98 ME XP DX 9.0 P4 1.8G None Yes n/p * Geforce 4 graphics. Pity 2 engines not playable. B17 Flying Fortress Atari 95 98 ME XP DX 8.0 P3 800 2 and 4 Yes Fantastic game with realistic crew. CFS 3 Microsoft 98 ME XP DX 8.1 P4 2 Yes Battle for Europe CFS 2 Microsoft 95 98 ME DX 7.0a P3 600 2 Yes Pacific theatre CFS 1 Microsoft 95 98 DX 6.0 P3 600 None Yes n/p * European theatre. Will not work with MultiThrottle connected to PC. FS98 Microsoft 95 DX 5.0 P2 350 2 No IL2 Sturmovik, Forgotten Battles, Ubisoft 98 ME XP DX 8.1 OpenGL P3 800 2 and 4 Yes n/p * Pentium III 800 or above Geforce 3 or 4 or above. IL2 Sturmovik Ubisoft 98 ME XP DX 8.1 P3 600 2 Yes n/p * Geforce 2 card or above. Flanker 2 98SE ? P4 2 No Screen lock-up. Try XP F18E 98SE DX 6.1 P3 600 2 No Will NOT play in Win XP F22 98SE ? P3 600 2 No Demo played OK Red Baron 3D 95 98SE Not XP DX 5.0 3DFX P2 350 None Yes n/p Run in compatibility mode for Win 98SE European Air Wars Microprose 98SE 3DFX DX 6.0 P2 350 2 Yes n/p * Will play in Direct X Crimson Skies Microsoft 95 ME XP DX 7.0a P3 800 2 Yes n/p NOT Win 98 or SE Flight Unlimited II 98SE OpenGL P3 800 2 No Not Win XP Battle of Britain 98SE ? P3 800 ? No Will NOT play in Win XP NOTES N/P = Not possible as tested by author: MultiThrottle configuration is NOT possible in this game. API = Application Programme Interface; A software written for games. Note: The minimum version of Direct X required is indicated. Sometimes the game plays only or best in that version, but as the latest version is supposed to be backward compatible, ALWAYS use the latest version first. Most Microsoft games play with Direct X 9.0c, the latest version at the time of writing. The other two common APIs are 3DFX Glide and OpenGL. CPU = Intel or AMD minimum recommendation to play reasonably well optioned. MEMORY: 512Mb absolute minimum. siliconchip.com.au OPERATING SYSTEM (OS): Although Windows 95 is listed above it must be ORS2 to work with USB. Quite frankly Win95 is now so old hat that it should be avoided where possible. Win 98SE much better. Win98Me quirky! ENGINES: By implication, ALL games listed have SINGLE engine aeroplanes. Only those games listed in the “Multi-engines” column have flyable aircraft. * Do NOT connect the MultiThrottle unit to the PC as it causes wrong configuration, so I found – and the joystick does not get the correct assignments. (If you really must stick your neck out, install and try the game without the MultiThrottle first. If everything works OK then plug in MultiThrottle. Should you not be able to juggle the assignments satisfactorily, unplug MultiThrottle, uninstall then reinstall game. You’re on your own!) August 2006 93 Calibration. ENGINE 1 100k LIN ENGINE 2 100k LIN ENGINE 3 100k LIN S2 S3 S1 ENGINE 4 100k LIN S4 5 1 8 15 D15 PLUG 9 12 Here’s the complete wiring diagram – with a matching photo below to make wiring really simple! Check and double check your wiring and if satisfied, plug the D15 into the games port of your computer when it is turned off. When you switch on your PC – assuming Windows XP Home or Pro – it will detect new hardware. You may follow the prompts but the preferred method is to CANCEL the automatic install and proceed as follows; CONTROL PANEL>GAME CONTRO LLERS>ADD>CUSTOM>JOYSTICK> AXES 4>BUTTONS 4>CONTROLLER NAME (what you want to name the controller is up to you – I called mine RobertMultiThrottle)>OK. Reboot the PC and ensure that the new controller is listed in GAME CONTROLLERS and its STATUS is OK. We assume your joystick or any other controller attached shows STATUS OK also. So far so good! Now calibrate the MultiThrottle exactly the same as you would a joystick. As previously mentioned don’t be too worried whether clockwise rotation of your pots give exactly what you expect. It is important that the full excursion of the axes is recognised and saved. Similarly, the switches need to be recognised as the relevant 1,2,3,4. Flight Sim Assignments is best placed with the cable at the left side for use with your left hand. Mount the components and push on the indexed knobs. Next prepare the cable using the commercial games extension cable. WARNING: Before you cut the cable, use a test meter or battery and lamp to check out that all 15 conductors are wired. Ensure that you chop off the unwanted end(!). Leave about 250mm cable connected to the socket as you may find a use for the discarded bit, like wiring wire!) and bare back a generous 150mm or so outer sheath. Strip off 3mm of insulation on all the conductors. Now trace out which colours go to which pins on the D15 games port plug. The colours shown on the circuit and wiring diagrams were those on 94 Silicon Chip the prototype but we cannot guarantee all cables/connectors will be the same. So double check which coloured wire goes to which pin and if necessary, correct the circuit and wiring diagrams to avoid later confusion. The circuit is basically standard game port wiring without using the Midi terminals, therefore only 10 wires out of the 15 are employed. The five D15 pins not connected are pins 5, 8, 9, 12 & 15). Identify which wires go these pins and chop off the bared 3mm on the 5 unwanted conductors to minimise the chance of short circuits. Anchor the cable inside the box with a plastic cable clamp then solder the wires as shown in the circuit diagram and wiring diagram. The logical designation of pots and switches is left to right equals port (left) to starboard (right) engines. It is beyond the scope of this simple project to give more than a few hints. Most who “fly” the games listed above will have some if not good experience of changing keyboard and joystick assignments. It is largely a matter of experiment. What follows is mainly for beginners. When a game is installed it usually loads its default or standard CONFIGURATION of controls. Unless you tell it otherwise, often the joystick will be detected as the primary controller. However with other controllers connected, when assignments are altered in “preferences” or “options”, to alleviate the frustration of setting up every time the game is played, many games allow you to SAVE the CONFIGURATION with a new given name, say Multi-Throttle. If this is not automatically the default when you next play the game, then select it manually. USB Operation For those PCs without a game port, siliconchip.com.au Flying a B17 This is chosen to demonstrate assignments as it is typical of the user-friendly type icon based games. (ie, non-menu type) It is also a very cheap re-released game with four propeller engines. Actual crew can be seen and moved around in the fuselage. A truly exciting game if you are not a die-hard purist simmer! Using the default assignments, the MultiThottle unit switches appear to work immediately as “Select Engine 1 - 4”. If not reconfigure as such. Throttles wired as previously mentioned, clockwise potentiometer rotation gives 100k-0k, which configures in “Engine One Throttle” = “Axis #1 (X), Controller #2, Normal.” “Normal” means that with clockwise pot rotation, the propeller increases RPM. Configure the other three throttles similarly. Note: Step by step instructions for “Engine One Throttle.” Click on “Engine One Throttle” and it highlights. In the opposite panel, click on “Axis”. As it scans rotate the Engine 1 pot fully a couple of times. This will be detected as shown. In B17 all propellers turn the same way – clockwise as seen by the pilot. This is not always the case. Some twin engine aeroplanes have the propellers turning in opposite direction to counter the torque effect. With a Lancaster bomber (A FS2004 add-on) the pull to port must be countered by opposite rudder or decrease starboard revs – not something you would do with maximum bomb load! In the early days getting B17 engines to start caused the author great frustration. At the bottom RHS of the game screen is an icon – a picture (Gif) – of a PC. This means that the PC is on AUTOMATIC and controls the flight. Press keyboard key “M” and the icon changes to a hand meaning – you’ve guessed it! – MANUAL control. At this point in external view, select Engine 1 on MultiThrottle unit, rpm minimum, then press key “A.” From this point B17 controls the start procedure beginning “Master Switch ON”, etc, finally “meshing” (cranking!) and away she goes. To stop an engine, again select the appropriate switch on MultiThrottle, then press key “S.” B17 controls selected engine shut down. Feathering, so that propeller stops windmilling, press key “D”. Now you are cooking with gas! FS2002 This is a much more sophisticated simulator used for “real life” flying rather than a game. (FS2004 is similar) They are not as user friendly as other icon based set-ups but their menu type assignments are very comprehensive. With a little trial and error the MultiThrottle unit is fairly easy to configure. The basic FS2002 has two and four engine jet engine planes but no such prop models. The Lancaster bomber as previously mentioned is an add-on. Rather than B17’s (Fig 7) style, Microsoft uses “tabs” and “drop down menus” to choose between Joystick or Keyboard assignments. It also has a separate window for setting sensitivities and deadbands, and many more keyboard commands. Observe “Joystick type” in Fig 8. Note that RobertMultithrottle has been selected. In the “Assignment list” Microsoft specifies a throttle as an axis. Click on “Engine 1 Throttle axis.” It highlights. Click on “Change assignment.” Rotating Throttle 1 potentiometer will cause x-axis to be recognised. Save the assignment. Engine 2, 3, 4, are recognised as y-axis, Throttle and Rudder (not visible in Fig 8) respectively. It may be necessary to use the “Reverse” mode (shown checked - an X within the box) to get correct throttle increase (clockwise=increase RPM). simply plug the Multi-Throttle unit 15 pin “D” plug into a USB Converter “D” socket, then plug the converter USB plug into any PC USB port. The green object on the left side of the desk (opening photo) is such a converter. It happens to be from Maplin (UK) but they are also often seen on eBay and other places on the ’net. siliconchip.com.au Set the converter to MODE 3 before booting the PC. Conclusion. The MultiThrottle Controller gives added interest to Flight Sims at little extra cost and may overcome the problem of ‘no games port’. The Multi-Throttle unit may work with other flying games but ask the retailer to verify before purchase or check the Websites. I’m not an expert on flight Sims. I am still grappling with the complexities of FS! The ability to control engine RPM individually has given me a real buzz. And make flying that much more SC pleasurable. Happy simming! August 2006 95 CIRCUIT NOTEBOOK Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates. Infrared remote extender This project sprang from the need to be able to remotely control audiovisual equipment placed inside cupboards. RF-based commercial units such as those used for home theatre were found to be overkill for this application. The circuit is based on a commonly available infrared receiver module (IRX1) and a PIC12F675 microcontroller (IC1) – see circuit. Most infrared standards specify a nominal 38kHz carrier signal for data transmission, which the module receives and demodulates. Digital data output Here’s how to install the parts on the IR extender PC board. 96 Silicon Chip The digital data output from the module is fed into GP2 (pin 5) of the PIC micro, where it’s received by the PIC program and duplicated on output GP1 (pin 6). This flashes the “Signal” LED to give a visual indication that the extender is receiving the remote control’s transmissions. In addition, the program regenerates the nominal 38kHz carrier and modulates this with the incoming signal on output GP0 (pin 7). This drives the bases of transistors Q1-Q3, which in turn drive three infrared LEDs positioned near the AV equipment. Note that the infrared receiver has an open-collector output that requires an external pull-up resistor. siliconchip.com.au ; IR Remote Repeater by Alex Sum ; V1.03A 11/12/2005 In this design, the pull-up is provided by enabling the PICs internal port pull-up on the GP2 input. Power for the unit is sourced from a 9-12V DC plugpack. A conventional 3-terminal regulator (REG1) reduces this to 5V to power the extender circuit. Diode D1 provides protection against accidental reversal of the power leads. Source code The panel at right lists the assembly language source code for the program. It’s a relatively short piece of code and a useful example for those learning about PIC microcontroller programming. The program and an accompanying flowchart is available for download from the SILICON CHIP website in a file named “IRREPEAT.ZIP”. A PC board for the infrared extender is available from RCS Radio – phone (02) 9738 0330 and quote board number RCS 5584s. Follow the overlay diagram to construct the board. The DC power connector (CON1) is available from Jaycar Electronics (Cat. PS-0520), as are the 3.5mm phone sockets (CON2CON4, Cat. PS-0123). The infrared receiver module is available from both Jaycar (Cat. ZD-1952) and DSE (Cat. Z-1955), while the PIC12F675 and its 16MHz resonator (X1) can be obtained from MicroZed (see www.microzed.com. au). Once built, it can be housed in an ABS project case. list p=12f675 ;list directive to define processor errorlevel -302 ;suppress message 302 from list file #include <p12f675.inc> ;default processor specific header file __CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _MCLRE_OFF & _PWRTE_ON & _HS_OSC & _CPD_OFF ; Constants Delay equ ; Data ; Code ORG 0x20 Statevar RES Cntr RES ORG goto ORG retfie ORG 1 1 0x00 MCUINIT 0x04 0x08 MCUINIT: BANKSEL ANSEL Clrf ANSEL clrf VRCON movlw b’00111100’ movwf TRISIO movlw b’01001000’ movwf OPTION_REG bsf WPU,2 BANKSEL GPIO clrf GPIO movlw 0x07 movwf CMCON movlw 0x00 movwf statevar sigwait: btfsc goto movlw movwf bsf cloop: movlw movwf movf xorlw movwf btfsc goto gp0low: bcf goto INPUT sigwait 0x00 statevar LED Delay cntr statevar,w 0x01 statevar statevar,0 gp0high t2now: btfss goto LEDoff: bcf signal: bcf goto btfss goto goto end ;RAM area ;carrier output toggle ;counter for T/2 ;reset vector ;interrupt vector ;return from interrupt ;program starts here ;bank 1 ;GP0-3 as digital I/O ;turn off VREF ;GP0-1 as outputs, GP 2 input ;weak pull up enabled, rising edge ;assign PS to WDT 1:1 ;GP2 weak pull up enabled ;Bank 0 ;turn off comparator ;read GP2 and check for Z ;no wait until Z ;make sure statevar is zero ;turn LED on ;(52-n)/y*dly01 ;toggle state Alex S is this m um on winner th’s Peak At of a las Instrum Test ent IRLED dly01 gp0high: bsf IRLED dly01: decfsz cntr,F goto notyet notyet: siliconchip.com.au ;should be (52-n)/y*dly01 ;y is number of instructions in dly01 ;n is overhead in cloop etc ;IR LED on GP 0 ;Status LED on GP 1 ;Input on GP 2 #define IRLED GPIO,0 #define LED GPIO,1 #define INPUT GPIO,2 Infrared LEDs The infrared LEDs can be mounted on a small piece of prototyping board and connected with 3.5mm mono phone plugs and 2-core cable. The author used both 3mm (Jaycar Cat. ZD-0100) and surface mounted (Altronics Cat. Y-1094) LED varieties. The SMD variety are particularly useful in this application, as they can be mounted on a tiny section of circuit board and attached to the infrared receiver window of the AV equipment with doublesided tape. Alex Sum, Eastwood, NSW. .7 ;reach T/2 yet? INPUT cloop ;yes T/2 now so check input again LED ;turn off LED, wait for more IRLED sigwait ;make sure IR is off as well INPUT dly01 LEDoff ;check input again August 2006 97 Circuit Notebook – Continued PICAXE battery protector While many low-battery cutout circuits have been published in the pages of Circuit Notebook before, this design is a little different. Its distinguishing feature is the ease with which the threshold voltages can be trimmed, thanks to the use of a PICAXE-08M microcontroller. Mains-derived timebase This simple circuit shows how to derive a 1Hz timing signal from the 240VAC mains. It would be useful in applications requiring time synchronisation or could simply be used to drive a clock circuit. A small 12VAC transformer feeds an optocoupler (OPTO1) via a 1.5kW current-limiting resistor, such that each positive half-cycle causes 98 Silicon Chip It can be built to work with 6-24V batteries and uses a MOSFET to switch the load. Power for the circuit is provided by an LM2940CT-5 +5V regulator (REG1). A low dropout type was chosen so that the circuit can operate with 6V batteries. The battery voltage is monitored via one of the A-D converter inputs (ADC4) of the PICAXE (IC1) after be- its internal LED to conduct. The negative half-cycles are shunted by diode D1. The output of the optocoupler is a square wave of 50Hz, which is applied to the clock input (pin 10) of a 14-bit binary counter (IC1). Outputs O0, O3 and O4 of the counter are ANDed by IC2a and then inverted by IC2b. As a result, when all three of the counter’s outputs go high, equating to a count of 50, the output of IC2b goes high, clocking ing divided down by resistors R1 & R2. When this voltage drops below the programmed lower threshold, the BASIC program sets a “flag” to indicate that the battery needs recharging/replacing. This flag is stored in non-volatile memory, so that its state is remembered even if power is disconnected. Next, the program writes a high to output2 to light the LED and a low to output1 to turn off the MOSFET (Q1) and interrupt load current. The microcontroller then continues to monitor the battery voltage and when it rises above the programmed upper threshold, the MOSFET is switched on again and the LED is turned off. A bypass facility is also provided for testing. When the program detects a low on input3 (ie, the “bypass” link is installed), the load is connected regardless of the battery voltage. The LED then flashes continuously to indicate bypass mode. Power must be removed to exit this mode. Note that a logic-level MOSFET, such as the MTP3055VL, is required to switch the load. Other types of MOSFETs may not be fully enhanced by the low (5V) the J-K flipflop (IC3). The flipflop is wired to toggle with each input clock pulse, so its output is a square wave with a one-second high/one-second low period. As is usual practice, 100nF capacitors should be connected between the power and ground pins of each IC and unused logic gate inputs should be grounded. Gary Smith, Montrose, Tas. ($30) siliconchip.com.au Listing 1: PICAXE Battery Protector ' Low Battery Cutout ' PICAXE-08M symbol lo=296 symbol hi=503 'low limit (turn off voltage) 'high limit (turn on voltage) main: if pin3=0 then bypass read 0,b2 'bypass for testing or adjustment purposes 'read recharge flag from memory into variable b2 main2: readadc10 4,w0 if w0>lo and w0<hi then check 'flag set if w0<lo then shutdown if w0>hi then start start: high 1 low 2 if b2=1 then clearflag 'read ADC on input4 into variable w0 'if w0 is between lo and hi then check if recharge 'if w0 is less than lo then turn off (shutdown) 'if w0 is greater than hi then turn on (start) 'switch output on 'switch off RECHARGE LED 'if recharge flag set then clear flag pause2: pause 1000 goto main2 'pause 1s before next reading 'loop shutdown: low 1 high 2 'switch output off 'switch on RECHARGE LED gate drive voltage, with the result being reduced voltage to the load and potential overheating of the transistor. The values of resistors R1 and R2 are determined according to the maximum battery voltage. In practice, their division ratio must be chosen so that the maximum voltage at the input to the PICAXE never exceeds 5.0V. Higher voltages may if b2=0 then setflag pause 50 low 2 pause 1000 goto shutdown 'loop clearflag: let b2=0 write 0,b2 goto pause2 'if recharge flag not set then set flag 'pause 50 ms 'switch off RECHARGE LED (flashes LED) 'pause 1 second 'clear recharge flag 'store value in memory 'loop back into start setflag: let b2=1 'set recharge flag write 0,b2 'store value in memory goto shutdown 'loop back to shutdown check: if b2=0 then start 'if recharge flag not set go to start goto shutdown 'else go to shutdown bypass: high 1 'switch output on flash: high 2 pause 250 low 2 pause 250 goto flash 'switch on RECHARGE LED 'pause 250 milliseconds 'switch off RECHARGE LED 'pause 250 milliseconds 'loop damage the microcontroller. For best results, keep the combined values of R1 & R2 at around 10kW. Note that if the battery is to be charged in circuit, the higher terminal voltage that occurs towards the end of charge must also be taken into account. Finally, the “lo” and “hi” values in the program must be set to suit your battery pack and divider ratio. Suitable values are easily determined by feeding the circuit with a variable voltage while monitoring the w0 variable using the debug command. Details on how to use the debug command to monitor output from the readadc10 command are included in the PICAXE manual. Terry Mowles, via e-mail. ($40) Contribute And Choose Your Prize As you can see, we pay good money for each of the “Circuit Notebook” items published in SILICON CHIP. But there are four more reasons to send in your circuit idea. Each month, the best contribution published will entitle the author to choose the prize: an LCR40 LCR meter, a DCA55 Semiconductor Component Analyser, an ESR60 Equivalent Series Resistance Analyser or an SCR100 Thyristor & Triac Analyser, with the compliments of Peak Electronic Design Ltd – see siliconchip.com.au www.peakelec.co.uk So now you have even more reasons to send that brilliant circuit in. Send it to SILICON CHIP and you could be a winner. You can either email your idea to silchip<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. August 2006 99 Circuit Notebook – Continued Automatic daytime running lights The safety benefits of using vehicle headlights during daylight hours is now well proven, with increasing numbers of vehicles including this feature as standard equipment. This add-on design provides a low-cost method of automatically activating the low-beam headlights when driving. With only a little added complexity, a useful delayed switch-off function has also been included that will light your way when you leave the vehicle at night! A fused feed from battery positive powers the low-beam lamps via the contacts of relay RLY1 and a 35A bridge rectifier (BR1). The series 100 Silicon Chip diodes reduce the voltage applied to the lamps, which substantially increases filament life for only a small reduction in brightness. Note that the bridge must be a metal-cased type and needs to be bolted to a large flat metal surface for heatsinking. Power for the relay coil is sourced from the ignition switch via transistor Q2. This transistor is controlled by the parking brake switch, so that when the parking brake is applied, Q2 is switched off and vice-versa. A second transistor (Q1) simply inverts the signal from the parking brake switch for use with a negative switched input. To use with a positive-switched input (ie, warning lamp and parking brake switch transposed), simply omit resistor R1 and transistor Q1, as indicated on the circuit. The relay coil finds ground through the high-beam lamp filaments. This causes the relay to switch off when high beam is selected, thus preventing simultaneous operation of both high and low beams. A 555 timer (IC1) wired as a monostable provides the delayed switch-off function. To activate it, switch the headlights off, on for a moment then off again. This triggers the 555, which drives pin 3 high to energise the relay. After about 29 seconds, the 555 times out, switching the relay off and removing power from the circuit. Graeme Duncan, Otago, Tasmania. ($40) siliconchip.com.au supply terminals. If you’d like to test the unit before connecting your (exp ensive) LED, temporarily connect a 10W 5W resistor in its place. Apply 9-24V to the input and measure the voltage drop across the 10W resistor; it should remain constant at about 3.2V. Note that not all chargers have an output filter capacitor installed. Typically, this is a 220mF 10V or 16V electrolytic unit. To save a few cents, the manufacturers sometimes leave this component out, relying on the mobile’s battery to perform the filtering task. If the 220uF capacitor is missing from your charger’s PC board, it should be installed before the supply is used. Use a 25V rated part if you intend to power the unit from more than 16V. This allows for accidental disconnection of the LED with power applied, where the output voltage will rise close to the input voltage. Finally, data on the MC34063 can be downloaded from www.onsemi. com and a useful development aid is to be found at www.nomad.ee/ micros/mc34063 Editor’s note: we described an efficient 12V fan speed controller, also based on mobile phone chargers, in the January 2005 edition. Dave Sime, Hughes, ACT. ($35) Fig.1: a typical switchmode battery charger as used in mobile phones. Cheap 1W Luxeon LED driver Step-down switchmode power supplies are often used in preference to their linear counterparts in applications where there is a large input to output voltage differential. Such is the case when driving Luxeon 1W Stars and their derivatives from a 12V DC source, which is the focus of this circuit. Mobile phone chargers based on the MC34063 switchmode controller IC are easily modified to operate as a simple constant-current source, suitable for powering a single 1W white or blue LED, or two 1W red LEDs in series. Defunct mobile phone chargers are readily available at local markets and on ebay.com. au for a few dollars. These units are quite easy to pull apart. First, unscrew the metal nipple from the end and remove the fuse, then prise off the metal collar that holds the two halves together. You can then easily separate the two halves and extract the circuit board. The circuit shown in Fig.1 is typical of most chargers, with some including a few extra components Fig.2: how to modify the charger circuit to drive a 1W Luxeon Star LED. siliconchip.com.au for indicator LEDs. Resistors R1 and R2 set the regulated output voltage, which can be calculated using the formula VOUT = 1.25(1 + R2/R1). This will result in a 7.1V output using the values shown. Because the MC34063 strives to maintain a constant 1.25V across R1, we can replace R2 with our 1W LED (Fig.2) and select a much smaller value for R1 using the formula I = 1.25/R1. Using a value of 3.9W, about 320mA of regulated current will flow through the LED. To modify the charger, start by removing R1 and R2. Note that the labelling of the resistors on the circuit board will probably be different; use your meter or follow the tracks on the board to identify the resistors of interest. Replace R1 with a 3.9W 1W resistor and wire the Luxeon Star into the R2 position using medium gauge hook-up wire. Keep the wire length as short as possible and make sure that you’ve connected the anode (+) to the positive output and the cathode (-) to the junction of R1 and R2. Do not connect anything to the metal heatsink of the Star; this must be isolated from the power It’s quite easy to modify a discarded mobile phone charger to drive a 1W Luxeon Star LED. August 2006 101 mini T h eremin Mk.2 PART 2: By JOHN CLARKE B Last month, we described the features of our new Theremin and gave the full circuit details. This month, we show you how to build it and describe the adjustment procedures. 102 Silicon Chip UILDING THE MINI THEREMIN is straightforward, with virtually all parts (except for the loudspeaker and switches S1 & S2) are mounted on a PC board coded 01207061 (188 x 103mm). This is housed in a plastic UB2 utility case measuring 197 x 113 x 63mm. Fig.5 shows the assembly details. Begin by carefully checking the PC board for any defects (eg, shorts between tracks or broken tracks). Check also that all the hole sizes are correct for the various parts. In particular, siliconchip.com.au Fig.5: install the parts on the PC board and complete the wiring as shown here. Note that the pitch antenna lead should initially be connected to point “X” (near T2), so that the equalising coil is bypassed – see text. check the hole sizes for the 6.35mm jack sockets, the DC power socket, the IF coils and the potentiometer mounting holes and redrill the holes siliconchip.com.au to a larger size if necessary. Note also that the corners of the PC board need to have cutouts as shown in Fig.5, to clear the four corner pillars in the case. If necessary, these can be cut using a small hacksaw and carefully filed to shape using a rat-tail file. Begin the board assembly by installAugust 2006 103 Table 1: Resistor Colour Codes o o o o o o o o o o o o o o o o No. 1 10 1 2 4 1 4 6 2 1 2 1 3 1 3 Value 330kW 100kW 47kW 22kW 10kW 4.7kW 2.2kW 1kW 680W 330W 220W 150W 100W 39W 10W ing PC stakes at the eight external wiring points, test points (TP1 & TP2) and the GND point (adjacent to VR2). In addition, PC stakes are used to terminate the leads from the equalising coil (L1). That done, you can install all the wire links using 0.7mm tinned copper wire. Note that the wire links all have a 12.5mm lead spacing. The assembly will be much faster if you cut a 12mmwide metal or wooden jig and use this as a spacer to bend the link leads. Follow the links with the resistors, using the colour codes in Table 1 as a guide to selecting values. It is also a good idea to use a digital multimeter to check each resistor before it is installed, as some of the colours can be confusing. The ICs, including the 4-pin optically-coupled LDR (OPTO1), can go in next, followed by the diodes. Make Table 2: Capacitor Codes Value 220nF 100nF 47nF 22nF 10nF 1nF 470pF 330pF 68pF μF Code 0.22µF 0.1µF .047µF .022µF .01µF .001µF NA NA NA EIA Code 224 104 473 223 103 102 471 331 68 104 Silicon Chip IEC Code 220n 100n 47n 22n 10n 1n0 470p 330p 68p 4-Band Code (1%) orange orange yellow brown brown black yellow brown yellow violet orange brown red red orange brown brown black orange brown yellow violet red brown red red red brown brown black red brown blue grey brown brown orange orange brown brown red red brown brown brown green brown brown brown black brown brown orange white black brown brown black black brown sure that all these parts are orientated correctly – OPTO1 goes in with the dot on its body orientated as shown in Fig.5 (note: the numbering shown on the pinout diagram in Fig.4 last month is incorrect). The capacitors can then be installed (see Table 2) but watch the polarity of the electrolytics. The JFETs and transistors are next on the list. Note particularly that Q6 is a BC337 while Q7 is a BC327. The remainder are all 2N-5484 or 2N5485 types – be sure to use the correct type at each location. Once those parts are in, the trimpots can all be installed. Orientate the top-adjust multi-turn types with the adjusting screw at top, as shown in Fig.5. The IF coils can then go in. Make sure that the black-cored can goes in the T4 position. The three white-cored cans go in the T1-T3 positions. Now install the two 3-terminal regulators (REG1 & REG2). As shown, REG1 (7809) is mounted horizontally, with its metal tab secured to a small heatsink and to the PC board using a machine screw and nut. To do this, first bend REG1’s two outer leads down by 90° about 8mm from its body and its middle lead down by 90° about 6mm away. It can then be installed along with its heatsink on the PC board and secured using an M3 x 6mm machine screw and nut, after which its leads can be soldered. Note that the leads are soldered last of all. Do not solder the leads before fastening the regulator to the PC board, 5-Band Code (1%) orange orange black orange brown brown black black orange brown yellow violet black red brown red red black red brown brown black black red brown yellow violet black brown brown red red black brown brown brown black black brown brown blue grey black black brown orange orange black black brown red red black black brown brown green black black brown brown black black black brown orange white black gold brown brown black black gold brown otherwise the PC pads may crack or lift due to stress as the screw is tightened. No heatsink is required for the 7808 regulator. It simply mounts vertically with its metal tab towards REG1. Next, install the 6.35mm jack sockets and the DC power socket. Note that we have specified high-quality 6.35mm sockets (Jaycar Cat. PS-0195) here. These have a shorter threaded bush than other commonly-available units, which will clear the side of the case when the PC board is installed. Note: standard sockets are not suitable since they have a longer bush. This would protrude through the side of the box, making it impossible to install the PC board. Potentiometers Before installing the potentiometers, it’s necessary to cut their shafts to length to suit the knobs. On the prototype, this meant cutting the shafts to 11mm. They can be cut using a hacksaw, with the end of the shaft secured in a vice. Having cut the shafts, break off the locating lug on each potentiometer. The pots can then be soldered in turn to the PC board, taking care to use the correct value at each location. The speaker/headphone volume potentiometer at the top of Fig.5 is the only logarithmic type. It will have an “A” marking (A = log curve) on its body (eg, “A10k”). Don’t confuse it with the 10kW linear pot used for the Skew control (curve B). siliconchip.com.au This is the fully-assembled PC board, ready for installation in the case. Note the earthing link that’s used to connect the bodies of the pots together and to the ground stake on the board. As shown in Fig.5, the pot bodies are all wired together and connected to circuit ground. This is done by soldering a 140mm length of tinned copper wire along the top of the pot bodies and then running a short link back to the GND PC stake. Note that the anodised coating on each pot body will need to be scraped away at the soldering points. Earthing the pot bodies helps prevent tuning changes due to capacitance effects when your hand touches the adjusting knobs. The plastic knobs also help to prevent tuning changes so be sure to only use plastic knobs. Once the pots are in, LED1 can be installed. Take care with its orientation – its anode lead is the longer of the two). Note that the LED should be mounted at full lead length so that it can later be bent over to pass through its matching hole in the front panel (this hole is in line with the potentiometer shafts). Coil winding The last component to mount on the board is equalising coil L1. It comprises a bobbin and two core halves and siliconchip.com.au is wound using 300 turns of 0.25mm enamelled copper wire. The coil is wound onto the bobbin after which the two core halves are fitted, along with a 2.5mm Nylon spacer. This spacer provides an air gap which lowers the effective permeability of the core. This lessens any variations in the inductance of the equalising core with respect to temperature. Winding the coil is straightforward – it’s simply a matter of winding on the 300 turns of wire and then twisting the leads together to prevent the coil unwinding. That done, trim these leads to about 20mm and clean the enamel from their ends, so that they are ready to solder to the board. Important: equalising coil L1 must be wound so that its self-capacitance is as low as possible. In practice, this means that the windings should be jumble-wound by hand without regard to neatness. Do not wind each layer with each turn neatly placed adjacent to the next. The core can now be fitted to the bobbin, as follows. First, insert an M4 x 25mm Nylon screw through one core half and install three M4 Nylon wash- ers (these effectively form the 2.5mm Nylon spacer). That done, install the second core half in position, fit the assembly to the PC board and secure it using an M4 Nylon nut – ie, the screw protrudes through the PC board and the nut is placed on the underside. Finally, solder the two coil leads to their adjacent PC stakes. Cut-outs & hardware If you buy a complete kit, the case will probably be supplied pre-drilled and with screen-printed lettering on the front panel. Alternatively, if you’re starting from scratch, you will have to drill the plastic case as shown in Figs.6-8. Basically, this involves drilling the following holes: • eight holes in the front side of the case for the pot shafts (7) and the LED; • holes in the lefthand end and rear side for the antenna brackets; • holes in the righthand end for the two jack plug sockets, the DC power socket, the two rocker switches and a banana socket; • holes in the bottom of the case to attach the metal baseplate and a ¼-inch August 2006 105 Fig.6: this diagram can be copied and used as a template to mark the hole positions in the ends of the case. Also shown are the details for the pitch and volume antennas. Tee nut (which is used to attach the stand); and • holes in the lid of the case to mount the loudspeaker and to let the sound escape. Note that the holes for the switches can be made by first drilling a series of three holes for each and then filing them to the required rectangular shape. The banana socket requires an elongated hole and this can be done by first drilling and reaming it to 6mm and then elongating it using a rat-tail file. As shown in the photo, the metal baseplate is attached to the underside (base) of the case and is secured using M3 x 6mm screws and nuts. The ¼-inch Tee nut goes in the centre 106 Silicon Chip and is glued to the baseplate and box using epoxy adhesive. Alternatively, you could use builders adhesive (eg, Selleys Liquid Nails). Note that an eyelet and short length of green hook-up wire is attached to the front left corner baseplate mounting screw – see Fig.5 Finally, the lid of the case requires four 3mm holes to mount the loudspeaker plus a pattern of 13 x 6mm holes directly in front of the loudspeaker cone. The antennas The pitch and volume antennas are both based on towel-rail end brackets and lengths of 16mm chromed steel tubing (or towel railing) – see Fig.6. The pitch antenna is cut to 375mm long, while the volume antenna is 125mm long. Plastic end caps are used to cover the exposed ends of each antenna while the opposite ends fit into the end brackets which in turn are attached to the case using M4 x 10mm screws and M4 nuts. Final assembly Now we come to the final assembly. The PC board simply clips into the integral slots inside the case but before doing this, it’s necessary to first remove the top screw that’s used to secure the mounting bracket for the Volume antenna In addition, it will be necessary to remove some of the ribbing inside siliconchip.com.au Fig.7: these are the drilling details for the front and rear sides of the case. The 7mm holes can be made by drilling small pilot holes first and then carefully enlarging them to side using a tapered reamer. the box adjacent to the DC socket and around three of the potentiometers, so that they sit flat against the sides of the case. siliconchip.com.au You can quickly determine what has to be removed by trial fitting the board inside the case. A sharp chisel can then be used to remove the ribbing. Next, solder the green earth wire from the groundplane to the GND stake on the underside of the PC board (ie, to the same stake that earths the pot August 2006 107 bodies). A second 150mm-long green earth wire should then be soldered to the GND stake on the top of the PC board for later connection to the banana socket. Don’t do this after the PC board is in the case, as heat introduced into the GND stake could melt the soldered joint for the groundplane lead without you knowing. You can now fit the washers to the pot shafts and insert the PC board into the box. This is done by angling it so the pot shafts enter the holes in the side of the box, after which the board can be clipped into the integral side mouldings. Once it’s in, secure each pot with its nut and fit the two jack socket nuts. The leads on the LED can then be bent down by 90° so that it goes through its matching hole in the front panel. All that remains now is to fit the two switches and the banana socket and complete the external wiring. Note that the connections to both the volume and pitch antenna brackets are made via crimp-connection eyelets which are secured under the nuts of the mounting screws. Initially, the pitch antenna wire should be connected directly to the PC stake marked with an “X” (adjacent to T2), to bypass the equalising coil (L1). It’s later connected to its correct PC stake after the setting-up procedure has been completed (more on this later). The connections to the two switches can either be soldered or made via spade connectors. The final wiring connections are to the loudspeaker and to the banana socket from the GND stake. Initial checks Fig.8: here’s how to drill the bottom of the case and the aluminium base plate. Make sure that the holes for the Tee nut are accurately positioned. Right: the threaded Tee nut is pushed through its holes in the baseplate and secured in position using epoxy adhesive. It accepts the threaded tip of the microphone desk stand. 108 Silicon Chip Now for the initial set-up procedure. Here’s what to do, step-by-step: Step 1: set trimpots VR9 & VR10 fully clockwise, VR8 & VR11 fully anticlockwise, VR12 fully anticlockwise and pots VR1-VR7 to mid-position. If necessary, now is also a good time to remove the indicator buttons from the knobs and replace them so that the pointers are vertical. Step 2: check that the power LED lights when power is applied. If it doesn’t light, check the polarity of the DC plug from the plugpack. The centre pin should be the positive. If this is correct, then the LED might be installed the wrong way around. siliconchip.com.au The PC board is installed in the case by first angling it down at the front so that the pot shafts pass through their respective holes in the front panel. The back of the board is then lowered and clipped into the integral slots. Step 3: check the supply rails to the ICs. IC2 should have 9V between pins 4 & 11, IC3 should have 9V between pins 4 & 7, IC4 should have 9V between pins 4 & 6, and IC5 should have 9V between pins 4 & 8. Step 4: connect a multimeter between test points TP3 and TP GND. Apply power and adjust transformer T4 for a reading of about 1.5V. Step 5: connect the multimeter to TP4 and adjust VR14 for a reading of about 7V, regardless of hand movement near the volume antenna. siliconchip.com.au Step 6: check each oscillator for correct operation by measuring the DC voltages on the drains of JFETs Q1, Q3 and Q5. These should each measure between 3V and 6V. Step 7: check the voltages on the remaining JFETs and transistors. Q2 and Q4 should have around 0.3-0.4V on their source (middle) pins; Q6 should have about 1.4V on its base (middle pin); and Q7 should have about 7V on its emitter. Step 8: vary VR3 and check that the voltage at TP1 ranges from about 0.7V to 7V. Similarly, varying VR4 should vary the voltage on TP2 over the same range. Step 9: set VR2 to its centre position and adjust the slug in T2 until a lowfrequency sound is produced from the loudspeaker. Check that the pitch of this sound changes in response to hand movement near the pitch antenna. This should start off at a very low frequency with the hand away from the antenna and rise in frequency as the hand is brought nearer to the antenna. Step 10: attach the microphone desk August 2006 109 increases as the hand is brought closer to the pitch antenna. Frequency changes with hand movement should now be quite linear for each octave up to 2048Hz. Note that if the antenna gives very strange results or the frequency does not appear to change, the resonance setting for the equalising coil is probably incorrect. In that case, adjust T2’s slug slightly anticlockwise and readjust T1 until the effect disappears. Volume adjustment The microphone desk stand screws into the Tee nut that’s attached to the underside of the case. stand to the unit and readjust transformer T2 carefully until the results are correct. Check that VR2 alters the tuning frequency. Equalising coil If this is all working, it is time to tune the unit with the equalising coil connected. Here’s the step-by-step procedure: Step 1: set pot VR2 (Pitch Range) to its mid-position. Step 2: wire up the test circuit as shown in Fig.9 using insulated wire. Note that the equalising coil lead must be lifted from point X and connected to the far left side of the board via a length of hook-up wire instead. Note also that the pitch antenna lead is moved to its correct location. Step 3: turn T2 slowly and find the point where the voltage is lowest. In the prototype, the voltage dropped from over 2V down to around 0.4V at the dip. The idea of this test is to find the frequency where the antenna and equalising coil resonate, as indicated by a dip in voltage as T2 is adjusted. Step 4: move your hand so that it is about 10cm away from the antenna. The voltage dip should change by about 50mV. By contrast, if you incorrectly set T2 at a position away from the dip setting, the measured voltage will vary by more than 200mV on this test. Step 5: verify this dip in voltage by placing the lid on the box (as this affects the reading) and placing your hand about 10cm away from the antenna. 110 Silicon Chip Now remove the lid, adjust T2 slightly, replace the lid and repeat the previous step (Step 4). Note: the Theremin must be away from metal objects or the results will be affected. Step 6: repeat step 5 several more times, adjusting T2 just a little each time (don’t forget to replace the lid after each adjustment). If the slug inside T2 has to be set at the top or bottom of its range to give the required voltage dip, you will need to change the number of turns on L1. Add a turn or two if the slug is at the top of its range and take off a turn or two if the slug is at the bottom of its range. If you cannot find the dip, check that the antenna has the same length and diameter as used in our prototype. The gap between L1’s cores also affects the resonance. A slightly smaller gap will give a lower resonant frequency and a wider gap will raise the resonant frequency. When you are satisfied that the resonance adjustment is correct, do not make any further adjustments to T2’s setting. Step 7: connect the equalising coil back into circuit by reconnecting it to point X, as shown on the overlay diagram (Fig.5). The two insulated wiring leads (shown green and orange on Fig.9) should also now be removed. Step 8: adjust T1 until the tone is at a low frequency, then put lid on. In necessary, readjust T1 so the tone starts off at very low frequency and One problem that you may have at this stage is heterodyning (ie, an audible squeal) in the audio output. This effect is an audible beat frequency which is produced by frequency differences between the volume oscillator and the pitch and reference oscillators. The solution to this problem is to adjust transformer T3 until the whistle disappears. Note that changing T3 may affect the voltage at TP4. If this drops below 6V, you may not hear anything at all and so T4 will need readjusting to bring TP4’s voltage back above 7V. Check again for spurious noises in the sound. Now connect your multimeter between TP3 and TP GND and adjust T4 so that voltage falls as your hand approaches the volume antenna. Set T4 so that the voltage on TP3 is around 1.6V. Note that if you set T4 so TP3 is at 1.3V instead, then the volume control range with hand movement will be less. This will cause the volume control to be more abrupt. Conversely, setting it at more than 1.6V will widen the control range with hand movement, so there will be more gradual volume control. Next, make sure that VR1 is set to its mid position, then set VR14 so that TP4 is at 6V when your hand is away from the volume antenna. That done, adjust VR1 so that the volume control range is nice and smooth. Waveform adjustments The waveform adjustment range is made by first setting VR3 fully anticlockwise and adjusting VR9 so that the reading at TP1 is 0.7V. Once that’s been done, set VR3 fully clockwise and adjust VR8 for 1.5V at TP1. The Symmetry range adjustment uses a similar procedure. First, set VR4 fully anticlockwise and adjust VR11 for 6.9V on TP2, then set VR4 siliconchip.com.au Fig.9: this diagram shows how to wire the unit for the resonance adjustments (see text). Don’t forget to restore the equalising coil wiring as shown in Fig.5 and remove the insulated leads after making these adjustments. fully clockwise and adjust VR10 for 0.9V on TP2. You can experiment with these ranges but be aware that with wider adjustment settings, the signal can drop out for particular settings of VR3 and VR4. Skew range The skew range is adjusted using VR12. This increasingly limits the skew range as it is turned clockwise and vice versa. You may wish to limit the skew range for several reasons. First, you will find that with too much skew control, the lowest frequency that can be played will be too high. This is because the pitch and reference oscillators lock together at high skew settings. The oscillators will only snap to a different frequency when pulled sufficiently by a large change in hand movement adjacent to the pitch antenna. Second, once a certain skew level is reached, further increasing the skew does not necessarily change the tone. Finally, too much skew will pull the reference and pitch oscillators so far off frequency that the pitch adjustment siliconchip.com.au This view shows the parts on the righthand end of the case. control will no longer be able to set the lowest frequency required. Adjustment of VR12 should be done with these points in mind. Earthing Finally, note that the Theremin will work best if the circuit earth connects to either mains earth or to your body. A mains earth connection is automatically made if the Theremin is connected to an earthed amplifier. However, if the Theremin is not earthed in this way, an earth strap can be used to connect between your lefthand wrist and the banana socket on the Theremin. A suitable (anti-static) strap is available from Jaycar – Cat. TH-1780. Alternatively, you could also run the Theremin from a 12V supply that has an option to connect the 0V rail SC to mains earth. August 2006 111 Vintage Radio By RODNEY CHAMPNESS, VK3UG The HMV B11A 5-valve battery-operated mantel receiver Manufactured around 1950, the HMV B11A is a battery-operated mantel receiver that was designed for use in rural areas. It was one of the first domestic receivers to use miniature 7-pin valves. B ATTERY-OPERATED RECEIVERS made between the mid-1930s and the late 1940s used valves that required 2V on their filaments and a high-tension (HT) supply of about 135V. This involved using a 2V lead-acid cell and three 45V dry batteries. These batteries were all quite expensive in one way or another. The 2V cell required regular recharging and this was usually done by the local radio serviceman or at a local motor vehicle repair garage. This was not only inconvenient but also meant that the household was sometimes deprived of the use of the radio for a day or two. The 45V batteries could not be recharged and were expensive to buy. As a result, battery-operated sets were usually only turned on when a specific program was being broadcast, then turned off. They were certainly not left on all day as background entertainment, because the cost of running them was too great. Of course, these sets were mostly located in rural areas that lacked mains power, so the batteries had to be conserved as much as possible. To lessen the cost of recharging and replacing batteries, valves were developed that only required 1.4V on the filaments and around 90V of HT. These became available around the beginning of WWII and used the octal valve base. Later on, around 1945, 7-pin miniature valves using the same voltages became available – to the military at least – and these had somewhat similar characteristics to their octal predecessors. Seven-pin miniature valves were subsequently used in consumer equipment in the late 1940s and continued in use up until the early 1960s when valves gave way to transistors. The HMV B11A This is the fully-restored receiver in its cabinet. Automotive cut and polish can restore old bakelite cabinets to “as-new” condition. 112 Silicon Chip HMV’s B11A comes in a “chunky” bakelite case and features a slide-rule dial scale which was quite typical of the era. There are only three controls: off-on-tone, volume and tuning. The set itself would have been aimed at the middle of the market. It is a broadcast band only receiver and instead of including a radio frequency (RF) stage as was usual in most 5-valve battery radios, this set has two stages of intermediate frequency (IF) amplification instead. This simplified the front end, as a 2-gang tuning capacitor could be used instead of a 3-gang unit. This siliconchip.com.au also meant that the associated extra tuning coil and adjustments were not needed. One drawback is that the dial scale has no provision for dial lighting, so tuning at night requires adequate external lighting. This no doubt was an economy measure. The chassis itself was originally designed to take octal battery valves, as evidenced by the small plates used to cover the holes where these valves were located. The 7-pin miniature valves use the same locations and so their sockets are mounted in the middle of these plates. Circuit details Fig.1 shows the circuit details of the set. It’s a fairly conventional superhet design with no surprises. The converter is based on a 1R5 which is neutralised via capacitor C5, with resistor R3 used to smooth out variations in the oscillator’s output across the band. The 457.5kHz converter output is then coupled to the first IF stage which uses a 1T4. Its output in turn goes to the second IF stage which also uses a 1T4. From there, the signal goes to the detector and an automatic gain control (AGC) diode in the 1S5. The resulting audio output from the detector/AGC diode is then applied to the grid of the pentode section of the 1S5 via the volume control. This in turn feeds the 3V4 output stage which drives the speaker via output transformer T1. The AGC signal is taken from the top of the volume control and is fed via R7 to R1, C3 & C11. The receiver uses simple AGC, as delayed AGC (DAGC) could not easily be achieved with the miniature battery valves that were available. However, this appears to have little effect on the receiver’s performance. The audio amplifier has two negative feedback loops. First, C25 gives some negative feedback to the screen of the 1S5 from the voice coil. The other loop is via C23 when it is connected to the plate of the 3V4. This capacitor can be switched to one of three positions and acts as a tone control. The 3V4 is the only valve which has bias applied to it and this is achieved using back bias resistor R14. The 1S5 obtains contact potential bias due to the high value of its grid resistor. By contrast, the RF stages have no standing bias. siliconchip.com.au Despite its rather grubby condition, this set was relatively easy to restore as all the original parts were still in place. The chassis was cleaned by first dusting it with a paintbrush and then using a kerosene-soaked rag and a kitchen scourer. This view shows the front of the chassis after restoration. The dial-drum is driven by a rubber tyre assembly. Note that V1 and V2 have AGC applied to them even with no signal being received. That’s due to the noise picked up on the antenna generating some AGC voltage. V3 has no AGC applied to it but will develop grid leak bias if the incoming signal is sufficiently great. One interesting little circuit quirk is the fitting of the radio frequency choke (RFC) CK1 in the filament supply line. This isolates the second IF amplifier from the converter and the first IF amplifier and makes the receiver more stable. As an experiment, I shorted out this RFC but found no evidence of any feedback anywhere across the broadcast band. Apparently, HMV wanted to make sure that there was no likelihood of instability in the IF amplifier stages. Dismantling & cleaning The radio was quite grubby when August 2006 113 This is the under-chassis view after restoration. The new components are hardly noticeable and this helps to keep the set looking original. The chassis is fitted with a roll-over frame and can be tipped into any position for servicing without damaging other parts. 114 Silicon Chip it came into my possession, having been stored for quite a few years after a nasty accident (more on that later). The back panel was held on by only one screw and this was removed, as were the three knobs at the front. That done, the two chassis retaining screws were removed and the chassis separated from the cabinet. The first thing I noticed was that the roll-over frame had four screws missing along the rear of the chassis. This problem was immediately fixed using some small self-tapping screws, after which the chassis was dusted using a paintbrush to remove any loose dirt. It was then rubbed down using kerosene and a kitchen scourer and a most of the muck came straight off. Admittedly, there was some corrosion where mice had been. Fortunately, their stay must have been brief, as little damage was caused. Having removed the grime, I oiled all the pulleys and bearings on the dial drive system, along with the various control shafts. That done, the dial-drive pointer guide was cleaned with a kerosene dipped rag and then oiled sparingly. siliconchip.com.au Fig.1: the circuit is a fairly conventional superhet design based on five miniature 7-pin valves: a 1R5 converter stage, two 1T4 IF stages, a 1S5 detector/ AVC/audio amplifier stage and a 3V4 audio output stage. The mechanics of the receiver were now working as they should, with one exception: the dial drive was a little “lumpy” in its action due to a flat spot on the drive rubber. It wasn’t bad enough to worry about, however. Next, the speaker grill was removed (it’s attached to the main part of the cabinet by four speed nuts), after which the cabinet (which splits into two halves) and knobs were given a good scrub in soapy water. Once dry, these parts were then polished using automotive cut and polish and this brought the cabinet up to as-new appearance. Overhauling the electronics With the cleaning done, it was then time to look at getting the receiver up and running. Inspection under the chassis showed an uncluttered layout, so overhauling the electronics was relatively easy. In fact, it would be nice if all receivers were as easy to service as this one. The four battery leads had seen better days, so I decided to replace them with new hook-up wire. There were no plugs on the battery leads so the circuit had to be carefully checked to determine where each wire went siliconchip.com.au – connecting the filaments to the HT lines would not have been nice! Having done that, I checked for a circuit between the filament positive rail and chassis. It should have measured just a few ohms but it was open circuit. It didn’t take long for the penny to drop – the previous owner had obviously connected the 90V HT line to the filaments and in a few milliseconds had blown the filaments in all five valves. As a result, I labelled the LT and HT leads appropriately to avoid making the same mistake in the future. Because of the previous owner’s carelessness, I had to replace all five valves. Of course, this was also the likely reason that the radio had been set aside in the first place. Fortunately, I have a good stock of new and secondhand valves, otherwise replacing them would have been an expensive exercise. In fact, two of mine were faulty as well, so I replaced seven valves in all to get the set operating. These battery valves have filaments that are rated at 50mA and are quite delicate. Even when all operating conditions are optimum, they have a shorter lives than their beefier mains-operated cousins. Before replacing the valves, I cleaned the sockets with Inox contact cleaner. I then connected my dry battery eliminator which supplies a variety of voltages to suit receivers like this one. The various connections were then triple-checked before applying power, to avoid wrecking the valve filaments again. With the fresh valves fitted and an outside antenna and earth attached, the receiver was up and running but its performance was poor. Most mains This close-up view shows the rubber tyre dial-drive system used on the B11A receiver. August 2006 115 This is the old B11A receiver before restoration. It was covered in dust and grime, having been stored in a garage for many years. receivers don’t require a separate earth to achieve good performance as they are “earthed” capacitively via the mains. By contrast, a dry-battery set does not have this “capacitive” earth and therefore requires an earth for best performance. A few quick checks revealed that the set was drawing normal current and the voltage readings on all valves were within specification with one exception – the voltage on the screen of the second IF valve was noticeably higher than it should have been. This valve didn’t appear to be drawing any current, so another 1T4 was fitted and then the set didn’t work at all! The reason wasn’t hard to find – its filament was open circuit. Fortunately, I had another 1T4 and fitting that made all the difference to the performance. The set was now performing quite well, although the front-end alignment was out, with stations not quite where they should appear on the dial. Alignment The alignment procedure for this set is quite straightforward. My first step was to set the receiver to the 621kHz mark on the dial, which is marked as station 3AR (now 3RN). That done, the oscillator coil slug was adjusted until 3RN came in. 116 Silicon Chip Next, I tuned to the position for 3AK (1500kHz) at the other end of the dial and set my signal generator to run at 1500kHz with tone modulation. The generator’s output was loosely coupled to the aerial lead (ie, placed near it) and I then adjusted the oscillator trimmer on the tuning gang until I heard the tone from the speaker. That done, I rechecked the oscillator coil adjustment at the low-frequency end and then at the high-frequency end again, as these two adjustments interact with each other. I then tuned to a nearby relatively weak station at the high-frequency end of the dial and peaked the antenna trimmer. Having completed the front-end alignment, it was time to align the IF stages. This should also be done with the set tuned to a weak station. However, I found that the IF transformers were all correctly aligned, so no work was required here. This didn’t surprise me, as the set appears to have had very little work done on it under the chassis. Finally, the various adjustments were all sealed using a dab of nail polish on the trimmers and re-melted wax (using a soldering iron) on the adjustment slugs. Capacitor checks Some readers may be wondering why my standard practice of checking all critical capacitors before switching on was skipped on this occasion. The reason is that because the voltages are relatively low in this battery-operated set, a few liberties were taken. However, once the set was working, I decided to take a closer look. Normally, I would replace audio coupler C24 and the two AGC bypass capacitors (C3 & C11). In this set, however, the audio coupler is a mica capacitor and had minimal leakage, so it wasn’t worth replacing. And if the two AGC bypasses have high leakage, it won’t harm the set – it just won’t work as well and will probably overload on strong signals. I checked the voltage on the grid of the 3V4 with a digital multimeter and it was normal. I then tuned the set to a strong station and measured -5V at the detector and only -2.5V on the AGC line. As a result, I replaced the two AGC bypasses and the voltage on the detector dropped to -3.5V (the voltage across the two AGC bypasses was also -3.5V). The AGC system was now working as it should and the audio output level was nearly the same on both strong and weak stations. Next, I checked the paper capacitors on the HT line and replaced any that had excessive leakage (as measured on my high-voltage insulation tester). I also checked the HT filter electrolytic capacitor (C22) and found that it had dropped to just 1mF. This was replaced with a 22mF 160V electrolytic, as I didn’t have the correct value (8mF). The receiver was now performing quite well and proved to be remarkably quiet with no signal coming in. It will operate quite successfully with the HT voltage as low as 45V. We often look at such simple sets and think that they cannot be good performers. However, as shown by this set, that assumption is often wrong. Summary The HMV B11A really is a surprise packet. It’s a rather unassuming little set but gives a very good account of itself. It is quite sensitive, has adequate volume and will work satisfactorily with nearly exhausted dry batteries. The design is straightforward and access for servicing is good. HMV receivers of this era have always impressed me and this one is no exception. It is a worthwhile addition SC to any radio buff’s collection. siliconchip.com.au Salvage It! BY JULIAN EDGAR The good bits inside flatbed scanners! It’s not hard to obtain a computer flatbed scanner for nothing – they’re a frequent discard that can be found at garage sales, kerbside rubbish collections and the tip. But what use can be made of the parts inside? Despite first appearances, quite a lot. Pulling a scanner apart is easy: most models just clip together and can be separated by the judicious use of a screwdriver. Inside you’ll find a moving carriage on which the cold cathode fluorescent lamp (CCFL), focusing lens and charge coupled device (CCD) image sensor are mounted. In addition, the carriage contains two or three mirrors to reflect the image to the lens. The carriage is driven by a geareddown stepper motor that operates a toothed belt. There’s usually also a position sensor to detect when the carriage is in its “start” position and, of course, the necessary image processing circuitry. So getting the bits is easy – but what can you do with them? The CCFL The Cold Cathode Fluorescent Light (CCFL) is run by a high voltage (HV) power supply which produces several hundred volts. Warning – it’s high enough to give you a nasty shock Many scanners use small stepper motors integrated into a reduction gear train. These make excellent hand-cranked generators (complete with a ~1:16 step-up ratio) or they can be used conventionally in a host of projects. siliconchip.com.au or burn your skin! In fact, given the right circumstances, a shock could be fatal. Salvaging this part of the system is very easy – in most scanners, the HV power supply is mounted close to the CCFL on the carriage or alternatively, is mounted remotely and is connected to the CCFL via some HV wires. The HV power supply is a separate circuit board and contains a transformer, inductor, a few capacitors and some transistors. The power supply is fed by either two or three wires. When there is a pair, you’ll normally find that they are red and black – red for positive, black for negative. Observing the polarity, connect a variable voltage power supply to these wires and slowly wind up the voltage. The CCFL will first light at anywhere from 4.5–21V but note that the HV power supply itself delivers several hundred volts to the lamp. If the original input voltage is unknown, don’t go up any more than a few volts over the “light-up” voltage of the CCFL. A 3-wire power supply also includes a “control” input (in addition to the red and black wires). If power is applied via the red and black wires, supplying this control input with a small voltage (eg, 1V) will cause the CCFL to light. CCFLs have some major advantages over other lighting sources. First, the tubes are extremely thin – 2.5mm is common. Second, they provide a diffuse light, usually with good colour rendition. And third, they are quite bright but at the same time remain cool! However, you must remember that the tubes are also fragile – where possible, they should be supported in exactly the same way as they were in the scanner carriage. Remember also that the power supply should be housed in a plastic case and the lamp August 2006 117 All flatbed scanners contain a Cold Cathode Fluorescent Light (CCFL) and its accompanying high-voltage power supply. It’s very easy to make these work separately from the scanner, to provide a free (or very low-cost) 2-3W fluorescent tube that can be powered by low-voltage DC! connections must be well insulated and away from probing fingers. Scanner CCFLs are typically rated at 2-3W and are ideal for use in model railway layouts (where they can provide concealed factory and station lighting), for low voltage lighting (eg, in a caravan or solar home) and for instrument and gauge lighting. Front Housing The front of the scanner consists of a flat sheet of high-quality glass mounted in a plastic housing. And that’s it – most times, the electronics, carriage and motor are all in the bottom half of the scanner. So what use is this top half? Well, it isn’t an electronic application but if the housing is placed over a shallow tray that’s been filled with soil, you get an ideal device for germinating seeds. Want some other uses? The front housing can also be used to protect solar cells that aren’t already under glass, or you can make a picture frame that matches the glass size. When I was a kid, I made a solar pie warmer that used a front glass sheet very similar in size to a typical flat bed scanner’s glass panel – so there’s another use. In short, wherever you need a precut, zero cost small sheet of good quality glass, here it is! Why on earth would you throw it away? Stepper Motor Scanners use stepper motors that are attached to compact reduction gears. Unlike many discarded consumer goods from which you can obtain steppers, the scanner stepper and its gear train often comprise a standalone, easily removable assembly. So if you want a small stepper (they’re typically 25–35mm in diameter) that’s integrated with a ~16:1 reduction drive and forms an assembly that’s only about Rat It Before You Chuck It! Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can 118 Silicon Chip easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you have a use for the highquality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! 70 x 50 x 40mm, reach for the nearest discarded scanner. To drive these motors, you’ll need a stepper motor control circuit. Of course, the scanner already incorporated this but it’s easiest to use new circuitry to achieve the control you want – eg, the Stepper Motor Controller kit described in the May 2002 issue of SILICON CHIP. Alternatively, you can apply physical effort to rotate the output shaft and so generate power! The 16:1 reduction ratio then becomes a 1:16 step-up ratio. By adding a crank handle to the output cog (this is easy because this cog originally needed clearance to drive the belt and so always stands proud), you can take advantage of the gear train to turn the stepper motor at an easilyachievable 1500 RPM! The resulting power produced is enough to charge a battery or run a white LED. For more on using stepper motors as alternators, see “Our Fantastic HumanPowered LED Torches” in the February 2004 issue of SILICON CHIP. The benefit of taking this approach over using a larger, direct-driven stepper is that a very compact generator or hand-cranked torch can be built. The disadvantage is that the plastic gear train may have a short life. Miscellaneous Don’t forget the other bits and pieces inside the scanner. I always salvage the chrome-plated steel bar on which the carriage rides (and it runs in bronze bushes, no less!). These bars are typisiliconchip.com.au contain a variety of pre-focusing lenses – and curved mirrors – but it’s the lens closest to the image sensor that’s the “good ‘un”. Often only about 8mm dia meter by 10mm long, these typically have a focal length of just of 15mm and make for extremely effective close-up hand lenses. They’re not super bright but they’re of excellent quality and provide huge magnification. They’re just the thing for inspecting solder joints or checking just how dull the ends of those supposedly sharp multimeter probes are! Finally, most scanners are powered by plugpacks and many people throw these away at the same time as they’re getting rid of the scanner. It’s worth keeping – you can never have too many different plugpacks on the shelf. Conclusion Here’s a use out of left field. A scanner cover makes the ideal top half for a small seed germinator. Alternatively, the glass can be used to cover solar cells, in small solar projects or even in a picture frame! cally 8mm in diameter and if you have a metal turning lathe and/or a set of thread-cutting dies, are excellent raw material for all sorts of projects. You’ll also find front-faced mirrors (that is, the reflected light doesn’t have to pass through the glass) and Halleffect position sensors. I’ve nearly forgotten one of the gems – the final focusing lens. Scanners Not interested in free low-voltage fluorescent lighting? Or seed germination boxes? Or geared stepper motors? Or hand-cranked generators? Or a compact, high-magnification hand lens? Or salvaging another plugpack without cost? That’s OK – just be sure you give any old scanners that you have to someone SC who can make use of them! From the publishers of SILICON CHIP PERFORMANCE ELECTRONICS FOR CARS NOT A REPRINT: More than 160 pages of new and exciting projects never published before – all designed to get top performance from your car. FASCINATING ARTICLES: 7 chapters explaining your car – engine management, car electronics systems, etc ADVANCED PROJECTS: You’ll build controllers for turbo boost, nitrous, fuel injection and much more! We explain the why as well as the how to! Available direct from the Publisher ($22.50 inc postage): Silicon Chip Publications, PO Box 139, Collaroy NSW 2097. Ph (02) 9939 3295; Fax (02) 9939 2648; email silchip<at>siliconchip.com.au or via our website: www.siliconchip.com.au siliconchip.com.au August 2006 119 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ASK SILICON CHIP Got a technical problem? Can’t understand a piece of jargon or some technical principle? Drop us a line and we’ll answer your question. Write to: Ask Silicon Chip, PO Box 139, Collaroy Beach, NSW 2097; or send an email to silchip<at>siliconchip.com.au TV signal transfer problem Are you aware of a device that can transmit TV RF signals room to room without coax cables or a VCR; ie, incoming RF from aerial to remote TV, not using A/V transmitters? I have an application where it would make life a lot easier. Perhaps you could advise? (I. M., via email). • One possible approach may be to adapt the portable masthead antenna described in the August 1996 issue. It will handle UHF and VHF signals. You would need to connect its output to a dipole antenna. connect it to my PC logging multimeter and want to know which pin I can get an analog voltage equivalent to EMF reading? (G. J., via email). • There is no convenient place to connect a data logger since the DC signal is a high impedance that is suitable for the ICL7106 but not a data logger. To enable a Data logger connection, you would need to add a 10kW resistor to the cathode side of diode D1 (this diode connects to the pin 6 output of IC2, an OP77). Then connect a 10mF capacitor to the end of this resistor to ground (plus side to the resistor). The data logger can connect to the capacitor terminals. Data logger connection for magnetic field meter Light dimmer has reduced brightness A few years ago I bought a Magnetic Field Meter, as featured in the October 1991 issue. It has an LCD panel meter and a 3-way rotary range switch and runs from a 9V battery. I now want to I recently assembled one of your projects titled “Touch/Infrared Light Dimmer” back in January & February 2002. It passed the low-voltage test using the small bulb as suggested in 10-Level Tank Gauge Wanted I recently wanted a water tank gauge and searched high and low for an economical commercial unit. My search unearthed the “Water Level Indicator” in the April 2002 issue of SILICON CHIP. Its only shortcoming was the 20% increment spacing. In my tank’s case, this represents about 7400 litres and I would prefer more accurate readings. It was noted that the LM3914 had 10 comparator outputs and I toyed with the idea of obtaining this kit and modifying it to accommodate 10 LEDs. However, I recognised the “Multi-Voltage Monitor” in the May 2006 issue as a similar project and I think I have my answer. If I construct this monitor, is there any reason why I couldn’t add the power supply, the “critical level” indication (if required) and a sensor 122 Silicon Chip array to convert this kit to the level indicator I desire? I see my main hurdle as the component selection for the sensors, where I now will have 11 sensor inputs as opposed to the original six. How do I calculate the resistor values please? As well as providing me with this answer perhaps you will consider a “Mark II” version of the Tank Level Indicator as I’m sure there are a lot of punters out there that would appreciate this luxury, especially now that there has been a droughtinduced tank population explosion in Australia. (P. W., via email). • The calculations for the resistors are quite tedious, particularly for 11 values. An easier method is to start out with trimpots and adjust these so the LEDs show correctly for each tank level. the article. And yes, I did change the .001mF capacitor back to 0.1mF but once I installed it, the unit can only reach ~25% brightness level. I suspect maybe the phase is too late, as shown on one of the scope shots published in the January issue. What should I do to troubleshoot this? By the way, I changed the 4MHz PIC16F84 to a 10MHz device and reprogrammed it with the hex file from your site. Did I miss something here? (H. H., via email). • The correct phase control is dependent on the correct detection of the mains waveform zero crossing. So the 680kW resistors and the 10nF (.01mF) capacitor at pin 6 of IC1 must be correct. Check them out. The 10MHz version of the PIC should be used and in fact is what we specified in the parts list. Use either the 10MHz or 20MHz versions. A 4MHz PIC cannot be used as we are running the PIC at 10MHz using crystal X1. Curious non-linearity in amplifier module I recently built two audio amplifiers using Altronics kits but replaced the LM3876T with a LM3886TF and dropped the rails to ±28V as suggested by you for a 4-ohm load. Both outputs are linear up to about ±9.5V peak-to-peak on sinewave but at this point the tops of the sinewaves clip. With increased drive, the bottoms of the sinewaves clip at about -22V which, for a symmetrical waveform, would correspond to 60 watts output. The linear gain was measured at 19 as expected. Have you any idea what may be wrong? Presumably, something must have happened to each LM3886. (R. E., via email). • This is an interesting problem which could cause anyone to tear their hair out. The likely cause is that you do not have both the supply pins (1 & 5) properly connected to the +28V rail. siliconchip.com.au Queries On 3-Phase Motor Controller Our electric cooperative serves a large sewer-lift station that utilises a solid state GE soft start on a 300 HP 3-phase 480V motor. We supply the station from a 480/277V transformer. They began experiencing problems while starting the motor from day one. I used a Metrosonics PA-9 PQ Analyser to capture the motor start sequence, including voltage and current waveforms both at the transformer and at the output of the soft starter. This particular soft starter achiev es a reduced voltage level for motor starting by utilising solid-state switching devices to turn the voltage applied to the motor off and back on at various points along the voltage waveform. After looking at the voltage waveforms coming from the soft starter (measuring Modifying the SLA float charger I have purchased several 12V SLA float chargers as described in the March 2003 issue. Rather than use an AC supply, I would like to be able to use a DC supply, as I have a large regulated supply that will at the same time be powering Nicad/NiMH battery chargers. What would be the best way of modifying the circuit? Can I complete the kit as normal and just feed the DC in on the correct rails or omit the rectifier part of the circuit? (G. I., via email). • You can build the circuit as it is shown and power the charger from DC. The supply voltage needs to be at least 15V. Alternatively remove diodes D4, D6, D7 & D8 and place a link in the D6 position. You can then use a minimum of 14.5V DC for the input supply. Bigger transformer for preamplifier I’m completing my third pair of SC480 50W amplifier modules. They will mate up with the Studio Series Preamplifier and the Studio Series Remote Control. I have a toroidal transformer on hand that I would like to put into service for the power supply siliconchip.com.au the phase-to-ground potential), I noticed that the waveform showed the voltage dropping below the zero level during the “off” time for both the positive half cycle and negative half cycle. Keeping in mind that the motor was connected in a delta configuration (phase-to-phase) to the soft starter and my measurements were phase-to-ground, do those zero crossings really mean anything? I have heard that a solid-state switching device exhibiting zero crossings on the output when connected to a sinusoidal source is a good indication that it is bad. Any information you can supply would be greatly appreciated. R. C., via email). • We are not at all familiar with the system you describe but we can make a number of comments. First, but it is 18V + 18V (at 50VA) and not 15V + 15V as specified. Although the difference seems slight, would it cause any problems, such as overheating regulators? (J. H., Falmouth, Tas). • Unfortunately, an 18V transformer is unsuitable for two reasons. First, the higher voltage will indeed cause excessive power dissipation in the voltage regulators, particularly when the headphone amplifier is installed. In addition, the rectified output voltage will exceed the voltage rating of the 2200mF 25V filter capacitors. Higher voltage (35V) capacitors will fix this problem but there may be problems fitting some physically larger variants on the board. Problem with telephone dialler I have a problem with the Telephone Dialler (April 2003) which I cannot figure out. When setting up and testing, it works fine and dials my mobile perfectly. However when I disconnect the dialler from my PC and turn off power and then hook up to modem and turn power on again, the LED flashes slowly (trying to get communication with Modem). It doesn’t matter what I do, I cannot get the dialler to go into scan mode (LED flashing faster). if the controller only varies the voltage and not the frequency to achieve soft starting then the only way it can do it is by phase-controlled switching, probably using Triacs or SCRs. Second, while Triacs or SCRs turn off when the current reduces to zero or goes slightly negative, the voltage can still swing quite a lot negative as the motor is commutated off. If the commutation from cycle to cycle is erratic, it could mean that the snubber networks across the SCRs/Triacs are not correct for the load. Of course, if the controller varies the frequency as well as the voltage, then none of the above applies because the electronics will use IGBTs. In any case, it sounds as though you need an experienced technician to check it out. To get the dialler to work, I have to disconnect the modem and hook up dialler back to the PC again. I then type (0) to simulate that the dialler has found the modem. Then WITHOUT disconnecting power to dialler, I just pull out serial cable plug it into modem then it works fine UNTIL you turn the power off which leads me back to square one. Why is it doing this every time I turn the phone dialler off? My guess was the configuration of modem but all the commands in article work fine. The modem understands everything. My Modem is a Dynalink 1456VQE. I am using the serial cable the modem came with for hooking up to the dialler. One more interesting thing I don’t understand is when the dialler is hooked up to the modem through its own serial cable, the SD and RD lights on the modem flash every time the LED on the dialler flashes while it’s looking for the modem. However when I make my own serial cable (not XOVER): pins 2-2, 3-3, 5-5, then the SD and RD lights on the modem do not flash. Is this a Dialler to Modem Communication problem? • The alarm dialler uses the AT command set in terse mode. That is, the response from the modem must be in single digit numbers not in words. For example OK is a 0 (zero). When August 2006 123 4-Digit Tacho Has Microcontroller Fault I hope you can assist me with the 4-Digit Tacho described in the April 2000 issue. I made it up and it appeared to be working OK but in trying to set up the calibrations I have run into trouble. When it was first turned on, I set it for a 4-cylinder motor and it seemed to be working. I then tried a couple of the other adjustments and now I cannot seem to get back to basics again; eg, I now want to set it for 8-cylinder operation. How can I reset the micro to the the alarm dialler is first turned on it sends out AT and waits for a zero response. As you have noted this can be simulated by typing zero on the PC when you are directly connected. Only when the alarm dialler gets the zero will the LED flash quickly and go into scan mode. As you have discovered, you can fool the dialler by sending it a zero 0 00 $10 I Z E P R OL! PO defaults and start from scratch? For instance, now when I turn it on I get --00 on the display and all LEDS lit and after a while it reverts to 000 with no LEDs. Any help would be appreciated. (G. B., via email). • If you cannot change the settings with the up or down switches, then perhaps the PIC needs to be reprogrammed. You should be able to change the “0” to any number between 1 and 12. If not, return the PIC to your kit supplier for reprogramming. from the PC and if you keep it powered you can then plug it back into the modem and it will work as expected. So the problem you are experiencing is that the alarm dialler is not seeing a zero when it sends an AT request. There are probably only two causes: (1) the modem is not programmed to respond in terse mode. Try connecting your PC directly to the modem and entering AT. If you get OK, then the modem is not configured correctly. (2) there may be a cable problem. The alarm dialler uses a 9-pin connector, whereas most modems use a 25-pin connector. The important thing to note is that the send and receive pins are reversed between 9 and 25-pin connectors. So you can’t simply connect pins 2 to 2 and 3 to 3. You need to have them reversed. If the cable is not correct then you will not be able to communicate. When a device is talking to a modem the SD (send data) and RD (receive data) LEDs normally flash. This is because the characters sent into the modem are echoed back to the device. If you don’t see any LEDs flash then the cable is wired incorrectly. High-voltage meter wanted Do you have a circuit for a highvoltage voltmeter that can measure up to 5kV? I need to know the voltage from a voltage multiplier that I am working on. The maximum voltage that I would like is about 3kV, so a full-scale meter 2006 SILICON CHIP Excellence in Education Technology Awards NOW OPEN SILICON CHIP magazine aims to promote the education, development and application of electronic technology in all fields throughout Australia. As part of that aim, we are announcing the SILICON CHIP Excellence in Education Technology awards, with a prize pool of $10,000. Separate awards will be made to students of secondary schools throughout Australia and to students of universities and TAFE colleges throughout Australia. AWARD FOR EXCELLENCE The secondary school awards will have three categories: (a) Best final year assignment of an individual student involving electronics technology (b) An award to the school sponsoring the winning individual student (c) Best school project involving electronics technology The university and TAFE college awards will have three categories: (a) Best project from a student as part completion of a degree, diploma or certificate in electronics or a related field (ie, mechatronics) (b) Best research project from a post-graduate student working in an area of applied electronics (c) An award to the university faculty or school sponsoring the best research project. Entries and judging The awards will be judged by the editorial staff of SILICON CHIP, convened as a judges panel. The decisions of the judges will be final. Entries for the 2006 awards are now open, with final submissions to be made by September 30th, 2006. All submissions will be confidential, until the winners are announced, in the December 2006 issue of SILICON CHIP. Each award will take the form of a cash prize and a commemorative plaque. All enquiries about these awards should be directed to the editor via email to: awards<at>siliconchip.com.au 124 Silicon Chip siliconchip.com.au readout of 3kV would be good. (R. B., via email). • We have not produced a high-voltage meter. However, in May 1999, we published three electric fence testers which could do the job. Alternatively, you could use the resistive divider string in one of them as a voltage divider to be used with a conventional digital multimeter. Mesmeriser clock has faulty LEDs I have built the Mesmeriser Clock featured in your June 2005 issue and I have a problem. The “seconds” circuit is working great, doing everything it should. My problem is in the four digits. There are quite a few LEDs that don’t come on at all. In fact, 26 LEDs don’t come on. I have checked my work over and over and even replaced U6 which is responsible for the digits. I would appreciate it if you could point me in the right direction on what I should be checking. (J. T., Renmark, SA). • The fact that the circle LEDs all work indicates that the column drivers (Q1-Q5) are working OK. We must therefore assume that the problem is related to the row drivers (U6). How you now proceed depends on what test equipment that you have available. First, disconnect power and measure the resistance between each output of U6 (pins 10-16) and ground. It’s possible that one output is shorted to ground somewhere on the PC board and the chip is being destroyed. Next, use your meter to do a continuity check between pin 8 of U6 and ground. Perhaps the IC socket is faulty and the ground pin is open circuit. If you have an oscilloscope or logic probe, power up and trace the signal lines back from the non-operational LEDs. You should immediately be able to see where the problem lies. We’d also suggest removing the PIC from its socket and checking for bent pins or damaged contacts in the socket. Using microwave transformers in a welder I am looking to buy an inverter “stick” welder but they are quite expensive compared to a traditional transformer type. I have come across an article on the web at http://www.dansworkshop. com/Homebuilt%20arc%20welder. shtml and I wonder whether you could comment on its design, safety, etc. Is this a possible project for the “Salvage It” column as it could save several microwave ovens from being entirely scrapped. (R. C., via email). • At first sight, building a welder from recycled microwave oven transformers is an attractive idea – it saves all those transformers. However, as pointed out in the link you sent, the transformer secondaries must be removed and rewound and then quite a lot of other stuff added to get a workable unit. By the time you buy all the necessary bits, you could easily end up paying more than $100 to get a unit which is pretty much a Heath Robinson affair. By contrast, you can pick up welders very cheaply on eBay and elsewhere and they would be safe and work well. Even apart from the dubious value, we would be reluctant to advocate people rewinding microwave transformers. Inevitably, someone would energise the unmodified transformer Notes & Errata RFID Security Module, June 2004: on the overly diagrams (Figs. 2 & 3), diode D3 should be labelled D2 and vice versa. and that is an exceedingly dangerous act. Transistor equivalents for PN100 and PN200 Could you possibly tell me some equivalents for the PN100 and PN200 transistors used in the Slave Flash Trigger, in the July 2003 issue? I live in the UK and can’t find PN100 and PN200 here. (E. J., via email). • Both the PN100 (NPN) and PN200 (PNP) are low-cost general-purpose bipolar transistors in the TO-92 plastic package, sold here as “multireplacement” types. They both have a Vcbo rating of 45V, a maximum Ic rating of 500mA, and an hfe (beta current gain) range of 80-600 at 10mA collector current. Here are some of the common devices listed as electrical equivalents but note that some of them may not be suitable for all applications. Some also have different lead connections, so you’ll need to check this as well: PN100 - 2N2222, PN2222, PN3565, 2N3704, 2N3904, BC337, BC547. PN200 - PN2907, 2N2907, 2N3906, BC327, BC557, 2N3702. For reference, the pin connections for the PN100 and PN200 are both CB-E when viewing the transistors from below, with the ‘flat’ side downwards SC and reading from left to right. WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act 1974 or as subsequently amended and to any governmental regulations which are applicable. siliconchip.com.au August 2006 125 MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $27.00 (incl. GST) for up to 20 words plus 80 cents for each additional word. Display ads: $49.50 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your credit card details, or fax (02) 9939 2648, or post to Silicon Chip Classifieds, PO Box 139, Collaroy, NSW, Australia 2097. _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $__________ or please debit my o Bankcard o Visa Card o Master Card Card No. Signature__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ 126 Silicon Chip FOR SALE More control solutions for you! NEW iUSBDaq Data Acquisition Module: features 8 12-bit analog inputs, 16 digital I/O, 2 PWM outputs, 1 high speed counter. High sampling rates. Free software, Labview driver and dll component. N1500LC Load Cell Panel Meter: New Low Cost, Great Accuracy, Fully programmable Indicator with 4-20mA and 2 relay outputs. USB to RS422/RS485 converter: with 1500V Isolation, RTS or Auto Data Flow control. Heaps of other features. Electronic Thermostats: with digital temperature displays, 2 control relays, can be used in heating and cooling. NTC thermistor or J TC or Pt100 sensors. Temperature and Humidity Sensors: Great accuracy, 4-20mA output. Wall and Duct mounting available. Signal Conditioners non isolated and isolated: convert thermocouples, RTDs to 4-20mA or 0-10V Fully programmable. Stepper Motors: we have a selection of Stepper motors for hobby and high torque CNC applications. DC Motors for both hobby and high torque applications. DC, Stepper and Servo Motor controller kits. Counter and Timers: 7-digit and 10year battery operated. Multi Function Timer and Cyclic Timer/ Pulse Generator Serial and Parallel Port relay controller cards. Pump and Trip Alarm controller card. Duty-Standby operation. PIC MicroProgrammers: serial and USB port operated. 2, 4 & 8 Relay Cards: suitable for TTL and Open Collector Outputs. Switch Mode, Battery Chargers and DC-DC converters. Full details and credit card ordering available at www.oceancontrols.com. au. Helping to put you in control. WEATHER STATIONS: windspeed & direction, inside temperature, outside temsiliconchip.com.au SPK360 3/5/06 1:10 PM Page 1 Adjacent Channel Filters 20 years experience! 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Quest AV® VGA Splitter VGS2 HQ VGA Cables AWP1 A-V Wallplate Come to the specialists... ® Quest Electronics® Pty Limited abn 83 003 501 282 t/a Questronix Products, Specials & Pricelist at www.questronix.com.au fax (02) 4341 2795 phone (02) 4343 1970 email: questav<at>questronix.com.au ELNEC IC PROGRAMMERS High quality Realistic prices Free software updates Large range of adaptors Windows 95/98/Me/NT/2k/XP CLEVERSCOPE USB OSCILLOSCOPES 2 x 100MSa/s 10bit inputs + trigger 100MHz bandwidth 8 x digital inputs 4M samples/input Sig-gen + spectrum analyser Windows 98/Me/NT/2k/XP IMAGECRAFT C COMPILERS perature and windchill. Records highs and lows with time and date as they occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch: phone (03) 9761 7040; fax (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Victoria 3137. ABN 63 006 399 480. www.davisinstruments.com.au PCBs MADE, ONE OR MANY. Any siliconchip.com.au Best high end DIY audio kits on the planet! www.aksaonline.com format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au RCS RADIO/DESIGN is at 41 Arlewis St, Chester Hill 2162, NSW Australia and has all the published PC boards from SC, EA, ETI, HE, AEM & others. Ph (02) 9738 0330. sales<at>rcsradio. com.au, www.rcsradio.com.au ANSI C compilers, Windows IDE AVR, TMS430, ARM7/ARM9 68HC08, 68HC11, 68HC12 GRANTRONICS PTY LTD www.grantronics.com.au QUALITY LED TORCHES, 1-watt: Fenix L0P & L1P, CIVICTOR V1 use a single AAA or AA cell. 3-watt: Fenix L1T & L2T with 1 or 2 AA cells. Fenix P1/Nuwai QIII & TM-301X-3 use 1 or 2 CR123A cells. The AIT Nightstar uses no batteries at all! www.torchworld.com.au/sc/ LEDS: SUPERBRIGHTS from just 25 cents each. Flexible LED light strip available off the roll in white and RGB. August 2006 127 Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. RFMA Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Advertising Index Altronics............................. 57,86-89 Amateur Scientist CDs............... IBC Aspen Amplifiers........................ 127 Av-Comm................................... 127 Dick Smith Electronics............ 34-39 Davis Instruments...................... 126 Dominion Electronics................... 99 Elan Audio.................................... 14 Furzy Electronics........................ 127 RF Modules Australia Low Power Wireless Connectivity Specialists VHF TX1 / RX1 Transmitter & Receiver TX1 $35+GST. RX1 $65+GST In stock NOW! Range: 5km+ TX1 I: 9.5mA RX1 I: 12mA Data rate: upto 10Kbps TX1H - 100mW now available Applications Rural Utilities Industrial Commercial Emergency Services Government UHF TX2 / RX2 Grantronics................................. 127 Harbuch Electronics..................... 69 Instant PCBs............................ 1127 Jaycar ....................... IFC,61-68,128 Transmitter & Receiver TX2 $19+GST. RX2 $39+GST In stock NOW! Range: 300m TX2 I: 10mA RX2 I: 13mA Data rate: upto 40Kbps TX2A/RX2A also available RADIOMETRIX: Low Power, License Exempt Radio Modules JED Microprocessors..................... 5 Laceys TV.................................. 127 Len Wallis Audio........................... 15 Microbric...................................... 57 MicroZed Computers.................... 71 RF Modules Australia, PO Box 1957, Launceston, TAS, 7250. Ocean Controls.......................... 126 Ph: 03-6331-6789. Email: sales<at>rfmodules.com.au. Web: rfmodules.com.au Quest Electronics....................... 127 Radio Parts.............................. OBC 12 volt LED lightbars, great for solar/ camping. Nixie clock kit $150. Giant LED clock kit coming soon – 265mm high digits! www.ledsales.com.au FLANAGAN TRANSFORMERS Australian manufacturer of: • Transformers 1P / 3P • DC power supplies • Custom battery chargers Phone (02) 9824 1095 www.flanagan.com.au ezChassis PRE-PUNCHED CABINETS for DIY amplifiers. Three heights, variants for valve and transistor amplifiers. Supplied with labels, screws and feet. Also heatsinks, handles and sockets. www.designbuildlisten.com RCS Radio................................. 127 POWER LEDs, Super Flux LEDs, 12VDC LED modules & blank PCBs. Quantity discounts. www.luxtronics. com.au RF Modules........................... 59,128 Just fill in & mail the handy order form in this issue; or fax (02) 9939 2648; or phone (02) 9939 3295 & quote your credit card number. 128 Silicon Chip Silicon Chip Bookshop........ 120-121 Silicon Chip Subscriptions........... 55 NEVILLE WALKER KIT ASSEMBLY & REPAIR: • Australia wide service • Small production runs • Specialist “one-off” applications Phone Neville Walker (07) 3857 2752 Email: flashdog<at>optusnet.com.au H Each binder holds up to 12 issues H SILICON CHIP logo printed on spine & cover Price: $A12.95 plus $A7.00 p&p per order. Available in Australia only. Buy five and get them postage free. Silicon Chip Binders................... 128 SC Perform. Elect. For Cars....... 119 KIT ASSEMBLY Silicon Chip Binders RS Components........................... 29 Silicon Chip Technology Awards. 124 Siomar Batteries............................ 3 Speakerbits................................ 127 Taig Machinery........................... 127 The Loudspeaker Kit.................... 33 Tribotix.......................................... 71 REAL VALUE AT Wavecom..................................... 51 P Worldwide Elect. Components....... 7 $12.95 PLUS P & WES Components........................ 11 PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. siliconchip.com.au