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August 25, 2010

During my college years, I worked in broadcast engineering at a television station, an FM radio station, and an AM radio station. For a time, I was also a Top-40 DJ in the era when there was more music than talk on AM radio. The limitations of amplitude modulated radio on 10 kHz channels meant low-fidelity in most cases. That, and the lack of a viable AM stereo technology, bumped music up to the FM band. Advanced radio technology finally enabled better fidelity and stereophonic sound on the AM band, but AM will continue to be dominated by talk radio.

Broadcasting technology has advanced very slowly over the years. The US Federal Communications Commission has been responsibly cautious in brokering the best and most economical listening and viewing experience for the public. This has forced it to delay some technologies and mandate others. Here's a short list of the FCC interventions that I remember.

Color Television - The FCC certified the NTSC color system, a color television system whose signals were compatible with monochrome receivers. Since hue was adjustable, NTSC was known to broadcast engineers as "Never The Same Color," but this was a good decision. All the older receivers still worked, quite unlike the recent switch to digital television. I'm a licensed broadcast engineer, and I wasn't able to digitally receive half the New York City stations that I received just fine in analog. That's even after designing and building a custom antenna (see photograph).

FM Stereo - Stereo was achieved by sending a subcarrier containing the (Left-Right) audio signal. This was combined with the main channel (Left+Right) signal to generate the Left and Right stereo signals. Since the main channel transmitted the (Left+Right), older receivers still produced a monophonic signal, and they didn't need to be replaced.

UHF Television - Television manufacturers preferred to produce sets without UHF tuners, so UHF television was going nowhere. With the passage of the All-Channel Receiver Act of 1961, the FCC mandated UHF capability on all television receivers. Alas, the set manufacturers took shortcuts, and the sensitivity of these UHF tuners was not comparable to their VHF counterparts. The FCC needed to impose a maximum 14 dB noise figure for UHF tuners, and further require "detent" tuning for UHF when it was used for VHF.

Cable Television - Cable television providers were required to air the signals of local broadcast stations. Surprisingly, the local stations at that time were more interested in increasing their numbers of viewers than trying to generate income from cable operators.

• Stereo Audio on Television - The FCC rejected stereo audio on television for many years, claiming the the impact of the medium was visual, not aural. This decision was actually a way to protect the nascent FM broadcasters, for whom stereo was their raison d'erte.

Digital FM Radio - Compatibility was maintained with older receivers, but there is more adjacent-channel interference. This has compromised my ability to detect meteors using a signal from a distant FM radio station.

Digital Television - This transition, in which analog sets became inoperable without a converter box, did not go well for me. I was forced to get a "cable" provider (fiberoptic cable in my case). Now, I rarely watch the New York City broadcast stations that I dutifully watched for thirty years prior. Bigger changes are set for the future, since video eyes are now migrating to the computer screen. According to a survey by the Pew Research Center, only forty-two percent of Americans say that TV sets are essential.[3]

A 600 MHz helical antenna with 15 dBi gain

A 600 MHz helical antenna with 15 dBi gain.

Radio broadcasting is now quite well developed, and I have a plethora of stations from which to choose superb audio signals at home and in my car. Instead, what I usually choose to do is play a CD in my car, and internet radio at home.[1] My son's entertainment source for his car is an iPod. Broadcast radio is losing its audience to the newer technologies. In what sounds like a modern version of the UHF tuner wars, various interest groups are presently lobbying Congress to enact a law that requires every portable device, including cellphones and PDAs, to include an FM radio.[2] The National Association of Broadcasters, quite naturally, supports such legislation; but the Consumer Electronics Association, whose members would need to stuff this extra functionality into their tiny devices, does not. Of course, an appeal to public safety sounds much better than a grab for market share:
"We would argue that having radio capability on cell phones and other mobile devices would be a great thing, particularly from a public safety perspective. There are few if any technologies that match the reliability of broadcast radio in terms of getting lifeline information to the masses."[2]
Everyone seems to be grabbing for what little money remains in the music business, and this particular item is just one of many that's confronting the broadcast industry.[4] How simple were the good-old-days of "Top-40, News, Weather and Sports."


  1. My tastes are somewhat eclectic. I usually listen to listen to Radio 8FM - Brabants Beste Muziekmix (Netherlands), Happyday Newage Radio (South Korea) and Technobase.FM (Germany).
  2. Nate Anderson, "Radio, RIAA: mandatory FM radio in cell phones is the future," Ars Technica, August 16, 2010.
  3. Pew Research Center, "Landlines, TV sets no longer essential, study says," Pittsburgh Post-Gazette, August 23, 2010.
  4. "Broadcasters: Act now to defeat a proposed tax that could kill local radio as we know it," The National Association of Broadcasters' noperformancetax.org web site.

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Linked Keywords: Top-40; stereophonic sound; Federal Communications Commission; Color Television; FM Stereo; UHF Television; All-Channel Receiver Act; noise figure; detent; Cable Television; NTSC; General Radiotelephone Operator License; helical antenna; Digital FM Radio; meteor detection; Digital Television; fiberoptic cable; internet radio; iPod; National Association of Broadcasters; Consumer Electronics Association; Radio 8FM; Happyday Newage Radio; Technobase.FM; Top-40, News, Weather and Sports.