Dennis,
When selective fading causes the carrier to drop far below the amplitude
of the sidebands, reinserting a carrier with a BFO is a way to improve
detection of the AM signal. This is not erroneous. The local
oscillator(s) and BFO must be stable for this to work. They do not have
to be accurate. It would be really nice if they could be controlled with
a smaller resolution than 1 Hz for those of us who can hear the
difference between a 1 Hz flutter (beat) and a slower beat. For most
amateur operation this does not matter. I was only using this as an
example of how most people CAN in fact tell the difference if the BFO
cannot be adjusted in smaller than 10 HZ steps.
Yes a real syncrhronous detector is a better way to detect an AM signal
with selective fading.
Ken N6KB
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