I have the v3 board as do you. I bought 10 diodes from Mouser and installed a replacement (twice) this afternoon. No improvement and still have the unsuprressed carrier. I also heated up the pins on T7 to check for a cold solder joint, looked over the entire board with a magnifying glass to see if I missed something. Loaded version CEC version 1.1 software, recalibrated, etc., without any success.
At the C50/C63 node, I am getting 1.4 mV without the microphone being keyed and 1.2 to 1.5 mV when the microphone is keyed. I looked very closely at the microphone jack for bent pins and can't see any.
As before the radio works fine on CW and receives well.
Any other thoughts?
Karl - W5QJ