Why do we use "radio station" and "TV channel"?

April 11, 2013 4:20 PM

I know that we have TV stations, actual buildings where the broadcast originates, and if you're not getting a clear signal on a radio frequency you might say "try another channel" on a walkie-talkie. But when it comes to the device in your home and you want to alter the signal coming in, you "change the channel" on the TV and you "change the station" on the radio. Why these terms for these devices?
posted by Pastor of Muppets to Society & Culture (9 answers total)

I chance the channel on the radio.
posted by Ideefixe at 4:29 PM on April 11, 2013

Well, with TV there are literally named channels (Channel N) which identifies which TV you're watching (within an area, of course). These actually correspond to frequencies, but people don't notice. With radio, there are a lot more "channels" and they aren't standard- there might be a station at 102.4FM in one city, and one at 102.8FM in another.

That, and there's so much more obvious syndication with TV. I don't really care what my local ABC affiliate station is, I just care which channel it's on.

For fun, I put the terms into Google's ngram viewer and you can see the Golden Age of radio with a big fat peak, which is cool.
posted by BungaDunga at 4:30 PM on April 11, 2013

Several television stations may share the same channel at different times of the day, which is at least why don't usually refer to them as "stations".
posted by 2bucksplus at 4:31 PM on April 11, 2013

So there are (were) government-defined channels for TV stations - if you see the definition for the old analog TV spectrum allocation in the US they're literally defined as channel 2, 3, 4, etc.

For radios while there is a spectrum allocation process we still define radio stations just by their broadcast frequency - 99.5, 101.3, etc. So there aren't specified channels. So we call them stations because we need to call them something and I guess "change the frequency" never caught on.
posted by GuyZero at 4:33 PM on April 11, 2013

We actually do say TV station when we use a station's call letters. Originally that meant the organization broadcasting from a single location. We say TV channel when we refer to the channel on the TV -- roughly the frequency that a given station has to itself.

WTBS is a "superstation" because it represents an original Atlanta station that now broadcasts countrywide.

If you took a TV from Boston to LA, there would still be a Channel 5 and a Channel 7, but different stations would broadcast in those channels.
posted by musofire at 4:37 PM on April 11, 2013

There are FM radio channels in the U.S. too but no one uses them.
posted by grouse at 4:37 PM on April 11, 2013 [1 favorite]

Best answer: Time for an old man to help clarify things, I think.

When I was a kid, 50 years ago, all consumer electronics was analog.

A radio had a tuning knob and an indicator dial which was labeled in KHz (AM band) or MHz (FM band). When you wanted to tune into a radio station, you had to remember what its assigned frequency was and tune to it, which is why stations announced their frequency regularly, to help teach it to you (1190 KEX!)

VHS televisions had a rotary knob, too, but it wasn't an analog tuner. It had little detents and could only go to a specific number of positions, 12 of them on the first TV we had. (No UHF; that came later.) The detent positions were labeled with channel numbers (2-13, for strange historical reason) and a given station would announce the channel it was on, to help you learn. (Channel 12, KPTV!)

So we got into the habit of referring to television broadcasters by their channel number. But referring to radio stations by their frequency would have been strange, so we called them by their call letters. (So, it was "KEX" but it was "Channel 12".) And since they didn't have channels, as such, we didn't call them that either.
posted by Chocolate Pickle at 5:53 PM on April 11, 2013 [5 favorites]

Radio signals (originally) were single frequencies. In the earliest days, very broad band and later, narrower AM signals (in 10 KHz steps in the USA), then mono FM (relatively broadband), then FM with a stereo subcarrier. Still, mostly just one dial selects one specific frequency.

TV channels transmit an AM video signal on one frequency and the associated sound intelligence on a related FM carrier frequency. Color data (in the old days, at least) went on yet another phase-modulated subcarrier 3.58 MHz off the video carrier. These trios of signals were specific to each 'channel' setting, and I suppose it was shorthand for explaining how this all worked to a population that mostly just wanted to turn the knob and watch Ed Sullivan.

The current method is more math than radio, very fascinating and a little arcane.
posted by FauxScot at 6:09 PM on April 11, 2013

There's a potted history here showing that the idea of "channels" came from the Radio Manufacturers Association (which was interested in making television, too, not as a turf thing) at the very birth of the FCC in 1933. Here, for instance: Television Channels Demanded. In short, the radio industry knew that the much greater bandwidth requirements of "visual radio" broadcasts, combined with much more straight-line signals due to wavelength, meant the necessity of reserving "channels" or essentially swathes of frequencies (said to be six times as much as a radio broadcast needs) so that there would be room on the air for all the stations that a metropolitan area might need.

While much of the early TV industry, in both form and structure, built on the radio industry, the two devices are quite different to end-users and it's not surprising that they developed different terminologies even for quite similar things. Other aspects came directly as we have seen from the implementing regulation.
posted by dhartung at 12:16 AM on April 13, 2013