History Wednesday: Frequency Manipulation

Today I took my daughter swimming at the condo association pool next to the Command Center. Being an exceptionally nice day in Boise, some of the neighborhood kids were already there. One of them had her iPhone or whatever plugged into a speaker, playing her list of jammin’ MP3s. This experience proved to be exactly as excruciating as it sounds.


You’d better “Beliebe” it.

Replace Justin Bieber with, say, Wham! and the iPhone with that noted paragon of past 2T culture, Z-103, and you’d have a scene very reminiscent of the Putt n’ Plunge during the mid-80s. Of course, my mind working the way it does I thought to myself, “Hey, it could have been Z-43.”

No, I’m not making an obscure Ed Wood reference here.

Now, as you young’uns may know, digital music was preceded by radio. There’s the older AM band, which popularized broadcast music before it became the realm of news, talk radio and other forms of wholesale buffalo slaughter. There’s also the FM band, which I understand still broadcasts something resembling music from time to time. Since I’m not a Belieber, I wouldn’t know about these things anymore.

These formats have coexisted peacefully for decades. It wasn’t always that way, which should come to the surprise of absolutely no one.

Anyway, AM radio first became a really big deal after World War I. While impressive in terms of such things as signal range, AM has some profound drawbacks. It’s prone to static. It can only transmit a limited range of sounds, and broadcasting AM in stereo is problematic at best. This is all fine and good when dealing with the spoken word. But for playing Hemispheres? Not so much.


In other words, even if Auto-Tune could help Rush Limbaugh, it wouldn’t.

In the 1930s an electrical engineer named Edwin Armstrong developed a solution to all this: FM radio. Although FM doesn’t have the range of AM, it broadcasts a much cleaner and richer sound. The FCC formally recognized FM radio in 1940 by assigning it its own place on the electromagnetic spectrum, 42 to 50 MHz. The first commercial FM station went on the air the following year.

I’m trying not to bore you with the science involved, but this is extremely important. Just bear with me here.

Now this was all fine and dandy, but it didn’t sit well with everyone. David Sarnoff, head of a little company called the Radio Corporation of America – or RCA – was one such detractor. By 1940 RCA was heavily invested in AM radio as well as pushing another newfangled medium of their own, television. However, for a variety of reasons RCA was well behind the curve on FM.

As it turns out old school VHF television broadcasts on similar frequencies as FM radio. Claiming FM would interfere with television transmission in 1945 Sarnoff convinced the FCC to move FM up the spectrum a bit, specifically up to 88.1 to 105.9 MHz. Some years later the FCC bumped the range up to 108 MHz.


Magnanimously paving the way for decades of interference-free Gilligan’s Island broadcasts.

So what? Well, there’s a small problem with this. First, shortly after the FCC moved FM radio it gave most of its original block on the spectrum to television’s Channel 1. Of course, if you live in the U.S., there is no Channel 1, not on TV anyway. For all practical purposes there never has been. Channel 2 – which I bet you are familiar with – has broadcast between 54 and 60 MHz since 1946, well above the original FM range. The other VHF channels occupy higher frequencies than that. The entire concept of a “Channel 1” was scrapped in 1948. Since then the original FM frequencies have been used primarily by police and fire departments.

In other words, apart from a handful of early experimental TV stations, there never was an FM/VHF conflict to begin with.

Even so, the FCC ruling effectively made every single piece of FM equipment used prior to 1945, from station transmitters all the way to FM radios themselves, instantly obsolete. Needless to say, Armstrong’s fledgling radio empire was destroyed overnight. Sarnoff even temporarily convinced the courts that RCA, not Armstrong, invented FM radio.

Despite its advantages, it would be another 20 years before FM seriously challenged AM on the American radio dial. Armstrong committed suicide in 1954 before he was exonerated.

So it could be said the reason Z-43 never existed was nothing more than good, old fashioned corporate greed. Fortunately we live in more enlightened times today.


No way we’d let this sort of thing happen again.
Image credit: Terence McCormack

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