Unfortunately it's also a spectacularly perishable food, and just a day or two in your refrigerator -- or an unplanned stop on your way home from the store -- can spoil your meal. You can often detect bad fish easily by smell or touch, but that's not always the case.nfortunately it's also a spectacularly perishable food, and just a day or two in your refrigerator -- or an unplanned stop on your way home from the store -- can spoil your meal. You can often detect bad fish easily by smell or touch, but that's not always the case.
In analog frequency modulation, such as FM radio broadcasting of an audio signal representing voice or music, the instantaneous frequency deviation, the difference between the frequency of the carrier and its center frequency, is proportional to the modulating signal.
For example [2], in North America, the maximum frequency deviation, â f, is 75 kHz for commercial FM broadcasting. If the maximum message frequency is equal to 15 kHz for audio, then Î²= kHz kHz =75 15 5, and the FM bandwidth is BW FM = + 2(5 1)15 kHz =180 kHz.This is close to the allotted 200 kHz channel bandwidth.he FCC has set modulation limits of 100% modulation (an instantaneous frequency deviation of 75 kHz corresponds to a 100 percent modulation) for stereophonic transmission and up to 110. percent modulation for SCA multiplex subcarriers under certain conditions [5].