Sync detectors and fading
 

Sync detectors and fading
 

In article . com,
wrote:

If the selective fading is as tight as you indicate, then there would
be "holes" in the audio spectrum of the recovered AM, much like a comb
filter. Sync demod won't fix that problem.

But the audio spectrum comes pre-equipped with a lot of holes* so there
is some benefit, as sometimes it's unimportant frequencies that are fading
out. (*That's why MP3 type psycho-acoustic compression can work).

There are too many people that think sync demod will cure everything.
It's just not true. Now if you have a nearby signal bleeding into the
desired signal, then pick the sideband the furthest away from the
interfering signal. Here, sync works great. If you have fading, you can
narrow band the signal by using one sideband. It helps a bit, but the
signal will still fade.

I find that there's a number of signals where (as close as I
can get to) sync detection (by zero beating the BFO in SSB mode)
cleans up the audio to the point where it's listen-able. Typically,
these are weak and fluttery high latitude path signals, Europe to
Western North America.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)