Data needed for Sanken amplifier module

Some years ago, I purchased some Sanken SI-1030G hybrid amplifier modules from David Reid Electronics. I built the amps but never actually used them. Now I do have a use for them. When I moved house two years ago, I discarded a lot of my old electronics documents and calalogs and inadvertently threw away the data on the amp modules.

I've contacted David Reid but they're not able to help me out. I've visited the Sanken website in Japan. The product is listed but identified as discontinued and Sanken do not have a contact email address listed on their site.

I'm hoping that some SILICON CHIP readers may be able to help me out with any data they may have tucked away. I'm primarily after the DC power rail voltage for this particular amplifier. I think it was 44V.

I know the 1982 David Reid catalog (plus or minus a year) contained the data and that's the document I discarded.

Mal Land,
intelectsol@hotmail.com

Data logging of speeding vehicles We have speeding vehicles and noisy vehicles in our suburban back street. The biggest problem is convincing the police/transport department that we have a problem. Could I suggest an electronics project that might be able to detect a vehicle's speed and noise level with the capability of logging the data into a computer? I am sure many readers of SILICON CHIP probably have the same problem. Neil Bruce, via email.

LED circuit overkill

On page 27 of the October issue there is a very wild bit of circuitry for a triple-LED version of a torch. Perhaps I am missing something because I cannot see the necessity for all this. Recently, I modified a flanged torch globe base to accommodate high-intensity white LEDs of 3mm diameter. These cost only $3.95 each and the light is quite adequate for my purposes.

I located the LEDs so as to preserve the focus of the reflector as near as possible. The light is white and is blindingly bright when viewed from the front. The best part of this is that the current is only 25mA. So I expect the battery, (two AA cells) to last a very long time.

John Gillard,
Cleveland, Qld.

Comment: if you are powering white LEDs from two AA cells the brightness will be far below what can be obtained at around 3.5V. There is a huge difference. If you don't believe it, try using three AA cells and feed each LED via a 47W resistor. The step-up circuit on page 27 of the October issue has the advantage that you get constant high brightness even as the cells go quite flat, giving long battery life.

Ignition switched via accessory line I am writing in reference to "Cranking Difficulties with Austin A1300", on page 91 of the October 2002 issue. As a hint, it sounds as though he has the ignition project powered from the accessories line (which is switched off during starting). After all, he does state that "the engine will run once the ignition switch is released to the running position". Tim Griffiths, Waratah, NSW. Comment: Yes, we should have picked up on this - we have been through this with other readers many times before.

RF projects should be available

One of your letters in the October issue suggested that more projects along the lines of RF and amateur radio should be included. I would agree with that.

A large proportion of the circuits I design and build for fun are RF-related, mainly simple VHF FM receiver circuits with as few valves or transistors as possible. (These days the program content of AM stations makes receivers for that band rather useless, except as a novelty, in my opinion).

For example, I built a 6-transistor super-regenerative receiver for listening to FM stations 10 years ago. I have been using it on my daily train trip to work and back ever since. I have also recently designed and built a miniature valve FM receiver using only a 12AT7. It drives headphones to an almost uncomfortably loud level. Crystal sets can also be made to work on FM.

Another favourite FM reception technique is that of using a pulse counting detector. This allows a simple resistance-coupled IF strip operating at about 200kHz.

I have often considered submitting these types of designs for your Circuit Notebook section but don't get the impression valve circuits or receivers that aren't stereo with .001% distortion are what your magazine likes to promote.

As for further ideas for projects, I think a lot of the designs from ETI and EA from the 1970s and 1980s could be brought up to date and redone, using modern components as well as perhaps fixing the design faults a few of these projects had. One particular project of interest was done by ETI to control a soldering iron by measuring the resistance of the heating element. This meant that any old 240V soldering iron could be used with no mods. I'm interested in adapting this for electric blanket control.

To end on the topic of nanofarads, I can see the necessity for change and although I have never used that unit of capacitance for my own work, mentally converting nF to μF is second nature as I read the circuit diagram.

John Hunter,
via email.

Comment: as far as valve circuits are concerned, it is true that we have a policy not to publish - after all, the magazine's title is "SILICON CHIP". However, we have nothing against RF or receiver circuits and we have a simple VHF FM/AM receiver featuring slope detection in this issue. If you have circuits of interest, please send them in.

Test equipment manuals wanted

Could you please ask your readers if (a) a circuit and manual could be bought or copied for a BWD 845 storage scope; (b) my old faithful BWD 509 had an accident and needs another tube, 5UPI(f); and (c) I also need a manual for a Topward 7046, 40MHz scope.

Graeme Muir,
PO Box 15,
South Morang, Vic 3752.
Phone (03) 9436 9100.

Keen reader endorsement

We've really enjoyed getting SILICON CHIP delivered regularly. While we've been buying it for years, it was disappointing the times it had already been sold from the newsstand or we just couldn't find a newsagency who carried it. We're a bit more settled now and will be renewing our subscription regularly.

You put out a thoroughly engrossing magazine and our back issues are as useful as the current ones. We've just built an infrared PC transceiver from the December 2001 issue after adding a little laptop to the PC menagerie. It's just the ticket for transferring files to and from the newcomer.

We particularly like the straightforward nature of SILICON CHIP, your readable articles, intelligent letters, pertinent ads (we both enjoy reading the ads and finding stuff to order), and your response to any issues raised.

Thanks for a terrific read each month.

Stuart Mullan & Eden Clarke,
Fingal, Tas.

Qualified reader endorsement I read with joy the letter from Mr Wilson in the October 2002 issue and I agree with him fully. I will be frank. I subscribe to your magazine because it is the only one left in electronics not because I enjoy all of it. I subscribed to EA for many years and I was a contributor to it about 1988. Under Jim Rowe, it was a very good magazine until it self destructed when it changed format. I miss the Radio magazine with its very interesting articles on all aspects of communication. A few months ago NOAA launched a new weather satellite which is giving wonderful pictures in the visual and infrared bands. It passes overhead every morning where I live west of Brisbane and I get coverage from Tasmania up to beyond New Guinea. On 12th September, 2002, India successfully launched its first geostationary weather satellite. We need a magazine that keeps us up to date with satellites. And scanners: I have an AR1500 scanner which goes up to 1.2GHz. I monitor the command centre for the fire service in SE Queensland. I monitor charter air services and the Ipswich Police and surrounds, including my town. Radio-mag used to give what they called "hot frequencies" for scanner users. We need some of that. I am isolated here but communicate using Packet with Ipswich via a Digipeater on a hill. There, there is a TeleText service bulletin board which I can use and also collect messages from a Digital club I belong to in Brisbane but never have visited. I want an electronics magazine that gives me "information" about what is happening in that world; news about space, satellites - commercial and amateur; what is going on in the radio world. What weird or funny stations are broadcasting and what they broadcast. What frequencies are the ambulances, rescue helicopters, etc using? Finally, a comment on the Publisher's Letter. I do wish you would use your Editorial to talk about electronics. The one in October is bad. You rave, and I mean rave, on about what a wonderful world it is now. I preferred the one 30 years ago. Now please do something about the extra articles as it is the only magazine that represents us, the technical readers hungry for news. I enjoy some of the magazine very much. Doug Thwaites, Esk, Qld.

Amateur radio articles not wanted

Having forgotten to respond to the letter from G. J. Wilson in the October 2002 issue, I was reminded by the letter of support from P. Dawson in the November 2002 issue.

Please don't change the magazine's format to include Amateur Radio articles. While I have an interest in RF engineering and projects like remote controls, 2.4GHz wireless, wireless video/audio, mobile phones, AM/FM radio trainers, model R/C, VHF/UHF & satellite TV, and VHF 433MHz portables, I'd rather not see articles on Shortwave, DX-ing, RFDS, NDB, marine and HF frequencies etc, in SILICON CHIP.

The very occasional article on Ham Radio would be more than enough. I believe there are other mags that cater for Ham Radio, although they may not be Australian. As you can tell from my lack of knowledge on those mags, I am not interested enough to spend much time browsing them in the newsagent, hence I don't want to see their content in SILICON CHIP.

EA was at least along the same lines as SILICON CHIP, apart from the latter years, and while I used to buy the odd EA if it looked interesting, I subscribed to SC, because it was always interesting, even if I didn't build anything from the issue.

David Boyes,
via email.

Solar panels have low output

Ben Haszard's letter (SILICON CHIP, November 2002) ignores a fundamental point. In my opinion, the best legacy we can leave to future generations is a society which encourages an inquiring mind and the development of individuals to their full potential and NOT "non-renewable natural" resources. To this end, SILICON CHIP performs a useful function in our society by disseminating technological innovations and publishing projects which encourage skill development.

As to Ross Tester's article about solar power, I decided to conduct some "real world" experiments using an Amp-Hour meter in a 12V set up. The power delivered by two 48W solar cells was so low (well below specs) that I need to rethink my experimental set up. So, Ross' analysis seems to be optimistic and the real cost/benefit may well be significantly below his numbers.

Frank Winter Ph.D.,
via email.

ETI480 amplifier not a bad design I am pleased to see that you have now got the copyright to all the ETI and EA articles. Have you been able to get the copyright for AEM? It had a few good projects also. I now wish to take issue with your comments on the ETI480 on page 31 of the October 2002 issue. About 20 years ago the then IREE Brisbane Audio Group embarked on a project of 2-way satellite speakers coupled with a powered subwoofer and electronic crossover. After some analysis by some technically expert members we settled on the ETI480 as it was available, cheap, had adequate specs, was reasonably easy to build and had "been around for a while". My guess is that it was/is one of the longest enduring designs in kit form produced by a magazine in the last 25 or so years. As a group activity we built many of these amplifiers. We had no trouble with any of them and I believe they are all still going, otherwise I feel I would have been contacted for assistance. We are totally bemused by your comments. In fact, reading your piece about the ETI480 in October and your own statement that you now own the copyright to the articles, it seemed like a case of taking a belated opportunity to criticise a design by someone else which just happened to be very successful in the "kit marketplace". You could have done that before October 2002 in a constructive manner and saved much angst by the students as well as using this as a springboard to an alternative design by SILICON CHIP. I understand that the ETI480 has some technical shortcomings (don't they all?) but I am hopeful that you are not going to demean yourselves by using SILICON CHIP as a forum to take a lot of cheap shots at other designs by now non-existent magazines. Keep up the good work guys and don't change the format. Ranald Grant, Brisbane, Qld. Comment: the short article in the October issue about the ETI480 may have seemed like a cheap shot and a belated one at that but the truth is somewhat different. First, concerning your point that we could have attacked the amplifier years ago, it was not our policy to publicly denigrate the opposition magazines or their designs. However, behind the scenes in years past we have made the kitset suppliers aware of our concerns with regard to this amplifier. Their response has generally been along the same lines as yours: the amplifier is cheap, has adequate specs and is very popular. It is this very popularity which has been very hard to counteract. And even though many people have got this amplifier module to run satisfactorily (ie, not blow up or evidently oscillate!), many more have had trouble with it.

In appreciation of SILICON CHIP

Yesterday afternoon I was having a quiet half-hour with October's edition of your magazine, reading and fathoming how each section of John Clarke's Speed Controller worked.

I came to electronics towards the end of the usual working life span and so find it all new with a fair bit of "black magic" involved. It occurred to me how much pleasure I was getting from the article, much like some people get doing crossword puzzles.

It also occurred to me that perhaps your group were not often made aware of the pleasure that readers experience reading SILICON CHIP. Thank you.

Name & address supplied but withheld at writer's request.