One point I forgot to mention was verifying that the K3 relay was in fact removing the audio to the audio amp.? I did this by measuring voltage a TP21 (>1 volt receive <1 volt on transmit) and that the M1 connection is open when the transmit relay is on (I used an ohm meter since a cap is the only connection to m1 when open.? If the device does transmit, this is a very slim possibility.? It would require an internal relay short on only one of the two sets of contacts.
