A common problem when installing the DADM is having noise at the beginning of a transmission. This is easily fixed with the addition of a wire from the 5K, 6K or 7K main board to the DADM board. The noise is caused by using ungated discriminator audio to feed the controller. The addition of the this wire controls an audio gate in the DADM to prevent the audio from reaching the audio delay line unless there is a received signal.
The ADM/DADM connector available in S-COM Controllers is a 4-pin connector providing power, ground, audio in, and audio out. A fifth connection is available on the DADM to control an on-board audio gate used to eliminate noise when the repeater is first keyed. Below are the connections to make from the DADM's COS connection on the DADM board (P1 Pin 5) on each controller and receiver:
7K Rx1 U27 Pin 11 7K Rx2 U27 Pin 8 6K Rx1 U15 Pin 4 6K Rx2 U15 Pin 3 5K Rx1 IC7 Pin 6
Once the wire is installed, set the COS Select for proper gating.