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Re RCA Australia. At the time I had applied for two position in the electronics industry and both were in the television, and as both my applications had been
by hilbert42 3y ago
Re RCA Australia.
At the time I had applied for two position in the electronics industry and both were in the television, and as both my applications had been successful I had to decide which one to take. The other position was closer to home but I chose RCA because I thought I would gain more experience working there. This, I reckon, was one of the best decisions I've ever made, working for RCA turned out to be an extremely rewarding experience as it cemented much of the type of work that I would be involved in through a significant part of my career. From RCA I went on to work in the engineering side of television broadcasting, and much later in my career I was involved in setting standards for industrial television systems for use in surveillance applications for a well-known international organization. The requirements were such that standards had to incorporate both encryption and authentication (the stakes were high and authentication a critical aspect of the tech). I was also involved in the early days of FM broadcasting in Australia, this work not only involved FM engineering but also politics (convincing government to introduce a new broadcasting service wasn't easy and not for the fainthearted but the dedicated work of many individuals made it possible and Australia's FM service first commenced in December 1974—this being the 50th anniversary year). My background working with RCA helped equip me for this task.
RCA Australia manufactured a range of electronic products including domestic stuff such as Hi-Fi amplifiers but its primary focus was on professional broadcasting and telecommunications products of the type broadly classifiable as line, terminal and distribution equipment as used by telcos, broadcasting stations and program production companies. For example, audio line equipment such as sound distribution amplifiers (SDAs), video processing equipment—video clamping and video distribution amplifiers (VDAs) and the like. Other work included setting up and maintaining imported film equipment (for telecine), studio television cameras, broadcast quality monitors (all usually of RCA manufacture), RCA Australia even had manufactured high powered television broadcast antennae for local consumption (those were the days when no one gave a moment's thought to them being plated in bright cadmium).
One of the huge advantages of working for RCA Australia was that I got to work with a very broad range of electronics and related equipment. One of the statements that Sarnoff makes in the The Story Of Television with which I wholeheartedly agree is that television brings together a very broad range of technologies, to quote "...I marvel at their accomplishment [referring to RCA researchers] bringing into focus the principles of radio, optics, electronics, photography and chemistry so that they might all work together to make color television practical..." To give him credit where credit's due it's a damn good summary of the technologies involved in television engineering although I'd have added physics (given that a good understanding of fundamental physics is necessary to design, say, image orthicon and vidicon camera tubes or shadow-mask color picture tubes), also one had to have a good understanding of advanced color theory such as CIE 1931 color space parameters (a brief look at the RCA Electro-optics Handbook will attest to this https://www.amazon.com/RCA-Electro-Optics-Handbook-Author/dp/B000LCIXW4 https://www.amazon.com/RCA-Electro-Optics-Handbook-Author/dp...).
I think perhaps the best way to illustrate why I believe RCA Australia ought to rate in any detailed history of RCA is the high performance of its professional products. Let me cite an example. The VDA (video distribution amplifier) type TA-100B was a solid state video amplifier with both bridging and matching input options and five outputs. It offered adjustable gain together with a plug-in cable equalizer module (which could be changed for optimal performance depending on the type of coaxial cable used), it was made in very large quantities at the Artarmon plant in Sydney and was used by both the common-carrier telco and by television stations, primarily the national broadcaster the ABC (then known as the Australian Broadcasting Commission). I knew one of the principal engineers at the ABC, Neville Thiele, and he kindly sent me copies of manuals written by him on pulse-and-bar video testing. Neville was a brilliant engineer, he was just as at home when designing television IF amplifiers (which he did at EMI) or when designing loudspeaker enclosures. He was also a very nice and helpful fellow (and it was through RCA that I'd gotten to know him).
Even by today's standards, the baseband performance of the TA-100B video amplifier for PAL, NTSC etc. would be considered very good but for its time of 50+ years ago its performance was exceptional. It had a differential phase and gain performance on 10 MHz T pulse-and-bar, modulated saw-tooth and other test signals of less than 0.1% which was around the limit of measurement of the differential phase and gain test equipment used at that time (today, a top baseband VDA should reach around 0.03%).
I recall seeing a test setup where a TA-100B launched a high speed 10 MHz T pulse-and-bar test signal from the equipment test bench at the Artarmon plant into the telco's coaxial feed which was received by Sydney's Test Room (the telco's main switching hub), which was about 10 miles away, the test signal was then rerouted to Melbourne via the then new intercity coaxial cable—a distance of about 545 miles (877kms), in Melbourne's Test Room it was then looped and rerouted back to Sydney's Test Room via the coax thence back to us at Artarmon—a total distance of well over 1000 miles. (Incidentally, back then the only telco in Australia was the Government's Postmaster General's Department which was responsible for all communications (telephone lines, spectrum management etc.))
I have a figure in my head for the number of VDAs used in the loop but I cannot guarantee its accuracy so I won't mention it but it was many hundreds. The outgoing feed and the received loop signal were fed into a Tektronix 465 dual channel oscilloscope on the test bench (which incidentally used RCA-designed Nuvistors in its input amplifiers), the two signals were then superimposed over each other using delayed sweep. What I saw almost defied belief, the T pulses when expanded and superimposed over each other appeared almost as one single trace albeit with a slightly fussy appearance caused by noise (the noise only increased the trace thickness by about half as much again (perhaps it was a just a whisker more—I wish I'd had a photo of the 465's screen that would have documented the event). Keep in mind the pulse-and-bar test signal wasn't the lower performance 5 MHz 2T pulse but the full T/10 MHz one. As far as I am aware, this exceptional performance was never published in journals and I only wish I had more information about the test (I wasn't responsible for setting up the test, after all back then I was the youngest and most inexperienced member of the prototype lab team).
Incidentally, the TA-100B VDA was designed by an engineer who left to work in the US just before I joined RCA but the chief engineer to whom I reported was quite brilliant especially in the area of filter design. BTW, the TA-100B used a very low impedance totem pole-type output stage which fed into an array of 75-ohm resistors to define its output impedance, this was quite novel for the time. I could say much more about this device and the work of the prototype lab [1] in general but unfortunately there's not the time nor space.
One final point, I was informed that after RCA Australia closed that RCA Switzerland continued to make the TA-100B. Sometime later a Canadian company whose name I've temporarily forgotten made a copy of the VDA (I've no idea whether it was made under license or just reverse-engineered). About a decade later I was visiting AVE (Australian video Engineering), a manufacturer based in Sydney that began operation after RCA Australia had closed, and the company's chief engineer showed me their VDA together with a copy of its circuit diagram, they also informed me that they'd based their design on one that originated in Canada. I instantly recognized it for what it was—an almost identical copy of RCA's original TA-100B albeit with a different circuit board design and mechanical construction! He was somewhat taken aback that I already knew so much about its operation and of its background. Right, the design that originated in the RCA prototype lab in Sydney had returned home after traveling full circle.
Finally, I can only repeat that I was very privileged to work at RCA Australia but it was just sheer good luck and happenstance that I landed the job when I did.
It would be good if anyone knows more about the history of RCA Australia and of say the test results of the equipment that was designed there, and or engineering details of the Sydney-Melbourne coaxial cable. I again failed to ask my former boss for these details before he died, that now is a matter of great regret. Incidentally, I still possess a handbook for the TA-100B, it includes a description of its operation together with a circuit diagram and complete parts list.
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[1] There was one important aspect about RCA's prototype lab that I forgot to mention. Its windows looked out and across the nearby railway line directly towards Channel 9's television tower. From the windows we had an excellent view of the antenna's radiating panels which meant the RF levels from the TV channel were exceptionally strong within the lab. Thus, breadboard and bird's nest type mock-ups of prototypes suffered considerable interference to the extent of it being common to see directly-demodulated TV video complete with TV sync block appearing within these circuits.
This was both a curse and a blessing. We became quite expert at suppressing and or eliminating the RF interference altogether from our designs. Ferrite beads and various other RF suppression methods came to the rescue. Our lab environment not only forced us to harden our designs against the direct injection of RF but also we paid particular attention to mains-borne interference including mains hum. It was commonplace to see ferrite beads on transistor leads and such, the beads also eliminated high frequency parasitics that were occasionally troublesome. In essence, the lab's poor and inadequate RF environment forced RCA Australia to build better products.