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.
Parameter fm is the frequency of the modulating signal, Î´max is the maximum deviation, and m is the corresponding modulation index. If a range of frequencies is used to modulate the carrier, the maximum modulating frequency and its corresponding modulation index are used.Commercial FM broadcasting uses a maximum deviation of 75 KHz and a maximum modulating frequency of 15 KHz.arameter fm is the frequency of the modulating signal, Î´max is the maximum deviation, and m is the corresponding modulation index. If a range of frequencies is used to modulate the carrier, the maximum modulating frequency and its corresponding modulation index are used.