Somewhen in the past there was a version of the SL621 AGC circuit
made with individual transistors.? Try searching the RSGB handbook
or tech topics.
Cheers,
William
On 03/09/2017 08:38 AM, Doug - via
Groups.Io wrote:
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Chuck,
? I am very interested in an AGC circuit for the BITX40. I have
already installed a new audio output amp - LM386 - that works
substantially better but on strong signals and a good antenna
there is distortion from some point onboard. Having to ride the
volume is a pain in the you know what. I was looking at my
radio-engineer handbook and one of the AGC circuits they show
uses the Plessy Sl621 AGC chip. I doubt it is still available
but if it was it would make things very simple. Google it, the
PDF data is still out there. This uses audio to establish AGC
that could be applied in some way to probably Q1 on the BITX
board.
