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.
