Thanks for the detailed reply, Len... I'll sit down and work through some of
the math if/when I get a moment.

Could you tell which of the following is correct? -- Say I amplitude modulate
my voice onto a carrier and feed it through a frequency multiplier. Besides
shifting the carrier, does it just make me sound like a chipmunk (i.e., if I
manage to hum a perfect 1kHz sine wave, the demodulated signal is me humming a
2kHz sine wave with a 2x mulitplier)? Or is there far more serious distortion
present?

---Joel