> Just a comment re those "broadcast-sounding" stations on 75 and 20:
>
> Almost to a man they are running Kenwood rigs that have been
> substantially modified with wide 6 KHz transmit and receive filters,
> low-frequency transmit and received audio response extended down to 40
> to 60 Hz, etc.
If they push the filter rigs down to 40 or 60 Hz they run the risk of not
suppressing the other sideband because of the slope of the filters. That is
why all filter rigs set the lower frequency at about 200 Hz.
Also, don't overlook the fact that they run high power with large, high
beams to
> deliver an S9+++ signal.
And some of them do not know how to handle such power. I hear their splatter
10 KHz away from the operating frequency.
Only the "digital SSB generation" type transceiver can achieve true low
frequency response. The other sideband is cancelled mathematically for
perfect opposite sideband suppression. We had great sounding SSB way back in
the '50s and '60s because we used "phasing SSB generation". This is not as
good as today's digital because it is impossible to get a phasing network of
physical components to be flat in phase angle across the entire audio
spectrum.
Tom, W7QF
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