I went home at lunch and looked through some of the various piles
of ham radio related paper that have made my desk and workbench
their home, and found some stuff I didn't know I had relating to
Corsair II AGC.
I haven't tried this out yet on my CSII, but the changes suggested are
to make R45 470 ohms (was 3.3K) and R54 1Meg (was 220K). R45 is the 3.3K
resisitor I mentioned in my last message, and making it smaller will allow
C34 to charge faster. If R45 is too small, the AGC will overshoot and
pop worse, so this needs some experimentation. R54 is the resistor that
discharges C34 rapidly when the "hang" time is over, and making it larger
will make discharge time less rapid.
I am also going to try using a .47 mfd tantalum for C34, instead of the 1 mfd
electrolytic that is standard. There is probably some interaction between
these values, so if I change enough of them I can probably make the pop a
lot worse. Many of my experiments seem to end this way.
In the Corsair I, the circuit is quite different, but R55 (82K) corresponds
to
R45 in the Corsair II, and changing R55 to 3.3K is the suggested value. C66
corresponds to C34, and it is already .47 mfd.
Tom W1EAT
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