Total posts : 45366
Quoting RFB, “To see any DC shifting, you would need to connect directly to those finals to see the DC shift itself. “, a shorted coupling capacitor does just this.
Perry, it is common that a transmitter signal will sound just fine on a receiver despite a distorted waveform. For example, the situation I mentioned with the shorted output cap. didn’t affect the signal since the DC wasn’t radiated. Also, ponder a signal rich in harmonics. The receiver only “hears” the part of the ensemble that it is tuned to receive. A listening test can fail to disclose a lot of problems.
Though you may not have the best scope available to you I find it hard to accept that a voltage measurement error would be of the magnitude you reported. Your measurements may not be that far from the truth.