Why do FM radio stations have a decimal in its frequency?

Answer 1

The whole commercial AM radio broadcast band runs from 0.55 to 1.7 Megahertz,

and the channels are spaced every 0.01 megahertz through the band. For the

listener's convenience, they decided way back at the beginning to multiply all the

numbers by 1,000 and talk about them without the decimal. So the AM radio dial

is marked from 550 to 1700, and there is a channel every 10.

The commercial FM radio broadcast band runs from 88 to 108 Megahertz ... about

9.5 times as much total space as the whole AM band. The FM channels are spaced

every 0.2 megahertz throughout the band ... 20 times as far apart as AM signals.

The channels are wider because the transmitted FM signal is wider, and can carry

more 'information' on it than an AM signal can. The FM numbers are simply more

convenient, easier numbers to remember than the AM numbers, so there was

never any reason to eliminate the decimal, and they're expressed directly in

megahertz.

To eliminate the decimal, you'd need numbers from 879 to 1079 on the dial,

with all the stations planted on odd numbers.

Or you could just chop off everything after the decimal point and throw it

away. The numbers would be easy to remember, but there could be as many

as 5 different stations all with the same number!