Backing off on the RF gain control IS cheating. Its taking away some of
the weak signal copying, kind of setting a threshold on signal AND
noise. I've been doing that on my HF radios (Collins, Tentec, Kenwood)
for several decades. Among other things it often reduces the signal
strength of unwanted adjacent frequency signals and so reduces their
bleed through the IF filter and reduces their chances of overloading the
RF/Mixer stages. And when there's thunderstorm static it more important.
Often those static crashes are short but carry a lot of energy that in
poorly designed crystal/mechanical filters is turned into a long term
ringing. In your tentec you will hear static as clicks. In a Kenwood or
Collins (or Icom too) you would have heard an extended crash from that
effect. Reducing the RF gain shortens the crashes in all radios.
Yah, its cheating, but it saves your ears. It says nothing about your
noise floor, all good receivers have enough excess gain to let the
external antenna noise set the system noise floor, some have more excess
gain that others. All are equalized with the RF gain.
With the RF gain turned back you may miss the weaker signals that are
down in the noise, but there are times when you want to hear voices, not
noise, then you back off on the RF gain.
73, Jerry, K0CQ
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Entire content copyright Dr. Gerald N. Johnson. Reproduction by
permission only.
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