CDM-1550 interface to JEI recorder

Signal911 · Post by **Signal911** » Thu Mar 28, 2002 4:37 pm

I'm trying to interface a CDM-1550 radio configured as a base to a JEI recorder. I have the JEI recording the rx audio just fine, but we also need to record the mic audio. Does anyone know how to do this? I remember seeing it done before, but don't know the specifics. (Need to be able to record what the dispatcher is saying through the mic (mic hi, mic-lo(ground-pin 7 in rear)). Any info would be very helpful.

Thanks,
Jeff Fehr

Will · Post by **Will** » Thu Mar 28, 2002 5:03 pm

Funny you should ask this as I am working on a simmular interface and am waiting for some info from Motorola engineering.

Alan · Post by **Alan** » Thu Mar 28, 2002 10:53 pm

I have done it two ways.

1) mixer amplifier. Mix both Rx audio and Tx audio to one source.

2) A PTT controlled relay. Rx audio on one pole. Tx audio on the other. Comon to recorder.