If your rig still has the M1 and M2 audio cutoff connections to relay K3, then what you are hearing in your audio is not a transmitter issue, but an RF overload condition from the TX output back into your audio preamp. In another post of mine I described how to eliminate this issue by cutting the paths in the audio from K3. The RF is so strong due to coupling between the contact pairs inside the relay that after you make the mod to not use the relay to interrupt the audio, you can use the righthand connection to the old R70 as a convenient RF pickoff to look at with a 'scope or a spectrum analyzer!
Larry N2AJX
