I built my second AGC kit board to see if that helped. Unfortunately, after installing it, now I have zero RF power out on TX. No RFI either :) . I've tried CW, SSB with the mic that worked previously, and using the Tune button in WSJT-X, all of which should cause some RF. Tried two different watt meters, both register zero. I can hear a small signal on my IC 7610 when I transmit on the uBitx, so it seems my problem is the PA stage.
I thought maybe the header pins that I soldered and glued to the uBitx board - where the AGC board sits - could be loose, but I am getting a solid 0.0 ohm continuity check between the pins and the trace on either side of where I installed the header pins. RX works fine, the RF gain control does what you would expect during RX mode.
I tried removing the AGC board and jumpering around the cut in the trace where I installed the header pins for the AGC board - same result. No power out.
I also tried removing the new AGC board and reinstalling the original one, same result. The original was giving me power out, but RFI in the headphones when I transmitted.
Maybe it's coincidental, but looks like I've broken something in the PA stage by plugging in the second AGC board kit. Does that seem possible? Any likely places to check? I know, probably a dumb question.