How does a transmitter work?
There are many types of transmitters. Thesimplest is the
Amplitude Modulated (AM) transmitter. This is an oscillator that
cycles at a predetermined frequency. This oscillator puts out a
level of energy that is varied by the sounds that you desire to
transmit. This variance is done from 100% of the signal to 0%. The
output then is two frequencies combined one at the stations
frequency and one at the frequency of the sound transmitted. The
receiver throws away the transmission frequency and amplifies the
frequency of the sound.
Bottom line is you only hear the sound stuck into the
F.M. is the same as AM but instead of varying power, we vary the
frequency with the desire sounds we want to hear. The receiver sees
that variance and converts that to sound.
Phase shift, DSB, SSB and the others are merely more complex
variances to these basics.