Mike wrote:
Everyone seems to have their own opinion about this, but I agree with
you, Barry. I vary the receive bandwidth to compensate for changes in
QRM and QRN , as well as to accommodate and enhance the frequency
response characteristics of the station I am trying to copy. It's
amazing how sometimes a small tweak can have a huge impact on
intelligibility. Having this flexibility reduces listening fatigue for
me, whether it's a rag chew, contest or weak signal DX situation.
IME this is very sensitive to implementation -- I find I'm often
wanting to tweak DSP and mechanical filters, but with a well-chosen
set of LC filters (Drake R8 series, for example) I'm content not to
have further adjustments. I think it is a function of group delay
and ringing, because DSP filters seem (to me) to need less tweaking
if they are set for rounder corners/less ringing/better phase
response than if they are screwed down tight.
Also IME, the LC implementations are far superior to any mechanical
or DSP filter in terms of fidelity and lack of listening
fatigue. Listen to an R390 and R390A side by side (where there are
few material differences besides the filters) for a very graphic demonstration.
Best regards,
Charles
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