Another data point...
I put a .01uf cap across the audio input the the AGC board (the Don & Kees kit) and it seems to have pretty much removed the audio from the speaker on xmit. I think it's still there but it's much, much less, just barely audible even with the volume turned up higher than I would usually have it. I didn't have a surface mount part so I soldered the smallest cap I had across the pins on the bottom of the board. Seems to have done the trick with no apparent ill effects. Many thanks to all who contributed to solving this puzzle.
Mark AA7TA
