clifto wrote:
Has anyone gotten a good oscilloscope look at the type of signals
that distort by cancellation of part of the carrier, i.e. the
signals that synchronous detectors detect much better than other
types? I'm wondering about the characteristics that make these
signals so hard to understand when they "fade" into that condition.

If you are talking about AM reception (and I think you are): I highly
recommend that you have some fun with an ISB (independent sideband)
receiver, with USB and LSB going into different ears. It's fun. Not
sure exactly what you learn :-).

I would also recommend that you look at spectra +/- a few kHz rather
than just waveforms. You can clearly see selective fading rolling up
and down under some conditions and hear the resulting distortions.

I too am generally interested in homebrew synchronous AM detectors. I
am not convinced that they are better than diversity antennas or ISB
listening (of course not everybody has diversity antennas or ISB
receivers.)

Tim.