Friday, July 29, 2016
VOLUME -26 NUMBER 5
Publication Date: 05/1/2011
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ARCHIVE >  May 2011 Issue >  Tech-Op-Ed > 

Everything Old Is New Again
Walter Salm, Editor
It was just past the mid-point of the last century — the fall of 1951 — and I was a freshman physics major at Schenectady, New York's Union College. I dutifully reported for drill instruction and courses in air navigation in the college's Air Force ROTC program — important since there was a war going on in Korea. The college also had a wonderful little AM radio station called WRUC (Radio Union College) in the Student Activities Building, and I was an ardent supporter and volunteer engineer, putting in many hours a week in the control room.

There were two large professional two-speed turntables (33-1/3 and 78 rpm) with nicely balanced pickup arms and turnover magnetic cartridges. Leroy Anderson's short orchestral piece "Blue Tango" was newly minted and topped the charts for an incredibly long period of time, played by Hugo Winterhalter and his orchestra. It was so popular for such a long time that we wore out at least a half-dozen copies of this recording, which were supplied gratis as promo copies with white labels on 78 rpm vinyl disks. After prolonged use, the vinyl would get badly warped, and the oh-so-precisely balanced pickup arm would eventually stop tracking and would skip grooves. All single promos were still issued on 78s; too few radio stations had professional quality turntables that provided the popular 45 rpm speed. LPs (33s) were generally reserved for classical music, complete Broadway Shows, and newly popular "albums". We also had a large library of "transcription" recordings — huge 16-in. diameter 33s that used 0.003-in. grooves — the same as 78s. These trannies played for a whopping 15 minutes per side, so we could run a U.S. government-created 30 minute program with just one break halfway through for announcements and commercials.

There was no automation. As a control-room engineer, it was my job to monitor the VU (Volume Unit) meters, keeping a hand loosely on the king-sized volume-control knob on a very intimidating-looking control panel. The next disk had to be cued up on the other turntable, ready to spin after a brief announcement from a golden-voiced announcer in the tiny announce booth.

We did some "live" shows as well, debates, discussions, and even some concerts from the relatively large "Studio B", viewable through the double glass from the master control room. This was up two steps and through a usually locked door, and housed the transmitter, and the awesome presence of a marvelous instrument of new technology called a tape recorder. The costly Magnecord benchtop machine was off-limits to all but top station engineering management personnel. To save wear and tear on costly acetate tape (before Mylar tape), we used paper tape for practice sessions and instruction, and being paper-based, it broke frequently. There was also a disk recording turntable, which we would use to record various musical themes that were played every night to usher in various program segments. The classical hour intro was the overture to Wagner's Die Meistersinger von Nuremburg, and we went through several home-brew recordings of this while I was there.

Much of the equipment in the station had been paid for by a local company called General Electric, which was always looking to employ engineering grads from the college. It was an excellent public relations investment on their part. I ended up working for them during the 1952 Summer "Vacation" at the company?s guided missile test station.

A fascinating aspect of the station's technology was its method of transmission. It did not go out over the airwaves as such, but used something called "Carrier Current". The station's AM signal was carried on the electric power lines all over the campus, and these power lines radiated the AM signal for a distance of up to 200 yards, which was, I believe, the maximum amount permitted by the FCC. Every once in a while, one of the engineers would get a little feisty and crank up the transmitter power, hoping to increase our coverage off-campus. I think they hoped to cover the entire city of Schenectady.

One day, a fellow student burst into the station and exclaimed that he just saw a truck with a funny-looking antenna on the top and the letters "FCC" on the side panels. Within a few seconds, the station's broadcast power output dropped dramatically. Such was the nervous way carrier current was used 60 years ago.

More recent uses of carrier current have included home remote-control centers, turning appliances and lights on and off remotely — usually operated from some kind microprocessor chip, often tied to a personal computer. All this leads up to a new, high-frequency type of carrier-current-like application — the "smart" electric power grid that is now nearing reality. NIST has been working to solidify standards and regulations that will allow this to happen (see Page 1), which in turn will lead to the installation of 50 million new "smart" electric meters at consumer sites (homes and businesses) throughout the US. Some are already in place while millions are on order. This is certainly a boost for the power meter manufacturing industry. Now the big question is, are they being made in USA or somewhere else? Stay tuned.  

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