Radio stations have never used arbitrarily-chosen channel numbers. FM goes by frequency, and AM by amplitude, plain and simple. But this thread isn’t about radio, it’s about television.
Analog television (at least in the US) has always assigned specific channel numbers to the frequency ranges. Sometimes they aren’t even in contiguous group, but the average person doesn’t need to know that. The important thing is that my tv set has a range of channel numbers that it can receive, and for each channel, the receiver knows what frequency to look at. Sometimes, especially in the pre-cable-tv days, and in non-metro areas, there could be many channels on which nothing is being broadcast, but the tv set didn’t care. It still knew which frequency is assigned to Channel 7, and it tunes to it, whether something’s being broadcast or not.
But in recent years, I’ve noticed a change. It seems that for many digital tv companies, the channel numbers are not simple integers any more. My mother’s cable system uses channel numbers like 14-1, 14-2, 15-1, 15-2, and so on. You can see an example of what I mean here. What is the point of this? Why not just number them with consecutive integers? Is there a significance that I don’t see?
[RANT] I have to admit, I’m not just curious. I don’t like this arrangement, because it means extra buttons to press on the remote control. They had to make a new “hyphen” button just for this! I think it might also make it harder to learn which station has which number. There must be some benefit to this craziness, and I want to know what it is. [/RANT]