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THE WAY I SEE IT By NEVILLE WILLIAMS Look out TV servicemen: VCRs are now disposable! With SILICON CHIP now celebrating its first birthday, it's appropriate to follow up on several matters raised in earlier issues. For example, to reinforce my remarks about "throwaway" technology (June 1988), a reader from Waniassa, ACT, points out that in the USA even VCRs may now cost as much to repair as to replace! As readers may recall, the subject was raised under the heading "For all practical purposes, Mr Fixit has had his day!" In commenting on the article, the correspondent (I.J.) professes a similar pet aversion to plastic assembly pillars moulded into equipment cases. "They can be a real nuisance", he says, "especially when the head of the screw is recessed deeply into its half of the appliance body. I've had to buy extra long Phillips drivers to access the screws in some units". Adding to the list of home appliances which we nominated as being virtual throwaway items, he has: • A garbage disposal unit with a burnt-out armature; • A fan heater with worn bearings; • A fan heater with an overzealous cut-out; • A fan with a stripped gear. But you can be lucky sometimes. He continues: I did have a win recently, involving a food mixer belonging to a member of the family. It used 'triwing' screws that resemble a Phillips head but having three slots instead 28 SILICON CHIP of four. By sheer good luck, a local tool dealer had a suitable screwdriver in stock and I was able to access and fix the fault. By the same token, I would dearly like to know where I could get a screwdriver to suit our 10-year-old Sunbeam mixer. It uses screws with three slots which start at 120° intervals around the circumference, aimed at the centre. The depth varies, however, being greatest at the circumference and diminishing to zero in the middle. What a fiendish combination! Incidentally, a couple of other readers have mentioned the possibility of picking up patented drivers at specialist tool shops although more frequently as the result of good fortune rather than good management. Domestic VCRs 1.J.'s information about domestic VCRs comes from the April 1988 issue of SPECTRUM magazine, official publication of the American IEEE (The Institute of Electrical and Electronics Engineers Inc). It reports that, in response to numerous complaints about consumer video equipment failure and the high cost of repairs, SPECTRUM staff recently investigated the situation. All suppliers contacted insisted that their products were inherently reliable but they would not release statistics to support these claims. SPECTRUM says, however, that an EIA (Electronic Industries Association) survey in 1986 showed that 7 % of VCRs required service within the first year and 43 % within the initial five years of operation. On this most recent occasion, those service organisations that were willing to cooperate indicated that VCRs are inherently less reliable than TV receivers because of their reliance on mechanical functions. The majority of present day service calls, in the American scene, involve dirty heads, electrical storm damage or jammed tapes the latter aggravated by "tight designs" which will not tolerate mishandling or misalignment. Again, economy models selling for around $200 often rely on belts and pulleys for tape traverse and, in consequence, suffer more mechanical failures than dearer models using direct-drive motors. When a microprocessor fails, the cost of replacement is likely to exceed $100, or half the original purchase price of an economy model. That is bad enough but the real crunch comes with motor and head replacements which may run to around $200. That puts economy models firmly into the "disposable" category - not worth fixing. In the same article (June 1988, The Ford Car as a Wireless Transmitter Having talked about EMC (electromagnetic compatibility) in the October issue, I was fascinated recently to come across the following item item in Vol.1, No.2 of "The Australasian Wireless Review" published in February 1923: "The Ford car as a wireless transmitter: Many and varied are the stories at present being told about the Ford car. From clubman to comedian, the name of Henry Ford is considered fair game. " But the statement that the Ford car is a transmitter of wireless waves, which are detected by sensitive valve receiving apparatus, is not in jest. It is cold fact. "The magneto of the Ford is of peculiar construction, corresponding very nearly to the high frequency dynamo employed by wireless stations for the radiation of messages. page 8) under the heading "The safety aspect", I commented on the legal aspect presented by home handymen and professional oddjobbers. They have long been able to dismantle and repair most home appliances economically, in many cases using replacement flex,, plugs, sockets and other parts available over the counter in local hardware stores. Because the practice has been so widespread, and not easily addressed by industry regulations, it has been accepted on the basis that most handymen, effecting such repairs, will do so intelligently. More specifically, and I quote, that they ''will not compromise the specifications on which the device was granted type approval in the first place". I suggested, however, that if this legal "grey" area was to be progressively eroded by throwaway technology, it might be outlawed by regulations spelling out exactly "who has the legal right to repair what, in respect to anything plugged into the power mains". Anything? Yes, anything. Start framing regulations about house- "The coils might be considered the equivalent of the high tension transformers and the sparking plugs as the equivalent of the wireless spark transmitter. The sharp click of the ignition sparks are clearly audible in a wireless receiver's telephones, when a Ford car is some hundreds of yards away. "It is even possible to detect a misfiring cylinder by this means, without ever having seen the car. "It has always been understood that the Ford possessed certain advantages enjoyed by no other make but that it numbers among its accomplishments that of a wireless transmitting station, as well as a means of conveyance, seems to be the strangest story of all" . From the same source, and still on the subject of wireless history, I include a "Tip for Fans" which may interest the many readers who hold appliances and you run headlong into the question of whether your average electronic serviceman can be permitted to touch the mains circuitry in a radio or TV set, or any other piece of electronic equipment. Think it through and you'll find yourself peering into a real "can of worms". Possible legal implications I drew attention also to the rising tide of litigation "where individuals can find themselves financially accountable for any harm caused by activities which are arguably negligent or illegal". There's much more to it than mere administration. One reader, who wishes to remain anonymous, obviously did think through some of the wider implications of what had been said. He suggests that knee-jerk regulations could disadvantage people other than just the "intelligent handymen and odd-jobbers" that I'd originally had in mind. If the right to repair mains operated equipment was to be limited to licensed electricians and others with specified trade cer- seem to be dabbling in old-time wireless/radio technology. I've never come across the idea before and I'm not very optimistic about its effectiveness but, to somebody, it must have seemed like a good idea at the time 1923. Using firm cardboard or fibreboard, the idea was to make up a tube such that a pair of headphones could be wedged and. sealed firmly against the ends, held in place by their own headband or maybe a separate rubber band. This done, a small flared horn was constructed, which was then wedged and glued into a matching hole in the side of the tube. This was a tip for optimistic fans , 1923 style . How to transform a pair of headphones into a (not very) loudspeaker. It must have sounded dreadful. tificates, it might also disadvantage graduate electrical engineers. In his own case, he said, official trade level qualifications could involve extra tuition and a test covering wiring rules, plus at least twelve month ' s p ractical experience in electrician's work. Even that would not necessarily meet-the requirements in all states. Rather bitterly, he suggests (and I abbreviate): "There is a feeling I have known about, ever since I graduated, that 'engineer type ' electricians are regarded as being inferior to those who did a normal apprenticeship; that while the system allowed for those other than apprentices to get their licence, it did so only under sufference. Were engineer type electricians seen as ri v als in the professional sense, or in terms of job displacement - taking work from ordinary electricians?" One must concede that, in respect to everyday electrical contracting, electricians have to learn and employ a range of very practical non-engineering skills, if their work is to be acceptable to both supply authorities and consumers. NOVEMBER 1988 29 THEWAYISEEIT-CTD But it would be curious indeed if regulations were ever to be framed and interpreted in a way which would prevent electrical engineering graduates from repairing any form of mains powered equipment with which they might become involved. Fly/ride/drive by wire In the October issue, under the above heading, I raised the question as to whether new high-tech aircraft and road vehicles, controlled by computerised electronics, could be at risk from electromagnetic radiation. Scarcely had the article been committed to publication (in August) than ABC TV put to air a segment of QUANTUM detailing continuing research by NASA into the physics of lightning. The research had been triggered by a frightening experience on November 4, 1969 on the occasion of a manned mission to the Moon. Thirty-six seconds into the launch and at a height of 2000 metres, the huge Apollo rocket was struck by lightning and all -communication was cut. Sixteen seconds later, there was a second strike which reportedly tripped every circuit breaker and interrupted the guidance system. A major catastrophe was avoided only by on-board software checking facilities. If 1969 reads like ancient electronic history, lightning struck again on March 26, 1987 when an Atlas Centaur rocket was being launched from the Kennedy Space Center. It was carrying a communications satellite. Seconds after take-off, lightning scrambled the Atlas Centaur's electronics, forcing the controllers to destroy the . $160-million vehicle and its payload. The irony was that the launch controllers had just previously elected to ignore a warning about the charged state of the atmosphere. NASA's lightning research program is headed up by Prof. E. Philip Krider, at Mosquito Flat, about 1km from the launch pad. Krider's team use small rockets to drag a fine wire aloft when the atmosphere is known to be lightning-prone. At a height of a few hundred metres the fine wire then provides a path along which lightning tends to track. By thus initiating lightning strikes more or less to order, it becomes possible to monitor them much more frequently and accurately than would otherwise be the case. Lightning figures facts and According to Krider, the instantaneous temperature created by lightning can be five times hotter than the surface of the Sun. The speed of a lightning strike is 20 to 30 times greater than had previously been believed, while the instantaneous energy level involved approximates the total nominal power consumption of the City of New York or the whole of Australia. A major objective of the NASA research team has been to develop instrumentation that can measure atmospheric charges and gradients from ground level and thereby avoid especially hazardous launch conditions. But according to QUANTUM, they are also concerned with identifying measures which could render electronic components less vulnerable in the first place - especially in The Space Shuttle - operational again but space junk poses a growing danger. situations where the use of composite materials instead of metal drastically reduces shielding. As if to emphasise that the research was of more than academic interest, Professor Krider made a point that, on average, every substantial aircraft flying the American skies is struck by lightning once a year! It certainly reinforced the oddball scenario suggested in the October issue: • Solid-state scientists working Research into the effects of lightning is of more than academic interest. On average, every substantial aircraft f1.ying the American skies is struck by lightning once every year! 30 SILICON CHIP diligently to produce increasingly complex chips using vanishly small (and delicate?) devices and tracks. • Aviation electronics experts devising comprehensive control systems relying ever more profoundly on those same chips - and electrical wiring. • Aircraft designers resorting more and more to composite structural materials, in some cases because of their strength/weight ratio, in others because they are less visible to radar. • NASA scientists hard at work trying to minimise the apparent vulnerability of on-board circuitry, especially in the face of reduced shielding by composite materials! Surely, there's more than a suggestion here of technologists putting the cart before the horse! And if that isn't sufficient to reflect upon or to debate over morning coffee, try this one. In that same October article, I drew attention to the fact that, over the past 70-odd years, we've come to rely more and more on the electromagnetic spectrum. But over that same period, we've managed to clutter it with a huge array of deliberate but dubious signals, plus countless avoidable sources of interference. We seem to have learned little about prejudicing a future resource. Also depicted on television recently was a representation of the globe, encircled by a huge assortment of space junk. According to the accompanying commentary, there are something like 10,000 pieces of identifiable junk currently circling the Earth, each piece a potential hazard to communications satellites and other space activities. At orbital speeds, said the commentator, even a particle as small as a flake of paint could prove fatal to a human being in a space suit a new slant on Russian (or other) roulette! In their passion to be the first with the latest, I do wonder how many space researchers, over the years, have paused to think that useable space is a finite resource. "Shoot first", runs the old saying, "and ask questions later". How neatly it summarises the birth of the space age! ~ SPECTACULAR ELEASE vifa NEWSA-100 SPEAKER KIT Since the introduction of VIFA speaker kits in Australia in 1985, thousands of speakers have been built with superb results. VIFA is now proud to release four new speaker kits ranging from a mere $399 to $1199 per pair including cabinets. Never before have speaker kits been so popular in Australia than after the heavy devaluation of the dollar. Similar fully imported quality loudspeakers are today typically 2-2½ times more expensive. And these speakers may very well be using Danish VIFA drivers anyway, as VIFA supply more than 50 of the world's most respected loudspeaker manufacturers with drivers. But why the big savings? Because fully imported speakers suffer from 25% import duty, 20-30% freight, 30% sales tax and 28% handling charges (typically). So if you would rather put your money into better quality than in other people's pockets, VIFA speaker kits are the only way to go. Are they difficult to build? No, the kits are supplied with all parts needed including fully built crossovers and pre-cut flatpack cabinets ready to assemble. No soldering or carpentry skills are needed, just a Phillips head screwdriver, some simple hand tools and a few hours of your leisure time. Are they as good as people say? Read the reviews, listen and compare with any other speakers twice the price or more. Need we say anymore? VIFA for the quality conscious audiophile. For full details please contact Sole Australian Distributor: SCAN AUDIO Pty. Ltd. P.O. Box 242, Hawthorn 3122. 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VDC OR Cut out and post this coupon to I Name (Please print) Post Office Box 740 I Address values: I . . . VDC __B_ro_o_k_~_1_e_, _N_.s_._w_._2_1_o_o_ _ _ L-~~~~~-~~~~J NOVEMBER 1988 31