I would check and see if you have already or need dc blocking between the URI and the mic input as the mic input most likely has dc bias for the mic cartridge... the URI does NOT like DC back fed. There are DC blocked inputs and outputs on the other row of pins.. I found that DC was an issue on most radios I am hooking to on both the TX and RX sides... It causes the audio to get unsymetrical...IN general I use those pins as they are capacitively coupled and most my issues like you are indicating.. stopped.. YMMV Just a thought to check... Doug KD8B Thanks Doug. The MICOR does indeed have such bias but I removed it by uninstalling the supply resistor in the exciter (ref: repeater-builder.com). My URI (modified FOB, not DMK) also has a blocking capacitor. Appreciate the suggestion. 73, Dave VE7MQ.