pix wrote:
... if anyone knows of a good description of all of the different distortions that come into play when an FM or AM radio signal is poorly recieved, please fill me in.
In AM the radio-frequency sine wave is Amplitude Modulated by the signal. In the receiver if the local oscillator is not running at the same frequency as the transmitter sine wave, you get sidebands in the signal whose frequency is the difference between the remote and local oscillators plus the frequency of the signal. This can be simulated in pd by multiplying [*~] two signals together, one of which is a sine wave [osc~], and the other is up to you. All the other distortions in radio are mostly noise, a constant background with bursts from lightning and motors. Whistlers are caused by lightning impulses bouncing around in the earth's magnetic field: different frequencies travel at different speeds, so the original click is smeared into a descending chirp of noise. . Martin.