FM Broadcast Radio Frequency Deviation
From Free Knowledge Base- The DUCK Project: information for everyone
The FM broadcasting range, which in the United States is between 87.5 and 108 MHz, uses a typical channel which spans from 100 kHz to 200 kHz, with a maximum frequency deviation of 75 kHz. This deviation of 75kHz can be both negative as well as positive.
- +/- 75kHz (Maximum Deviation)
The most basic FM broadcast transmission has the carrier present at 30 Hz, and the modulating frequency is 5 Hz. With a modulation index of 3 the peak frequency deviation about 15 Hz suggesting that the frequency will vary between 15 and 45 Hz.
Simplified: deviation is the actual modulation (volume) level, whereas bandwidth the the amount of space needed for the full FM transmission.
