C200 Tone Remote Desk Set

The C200 desk set doesn't use a RIB, the mic/accessory connector actually has RS232C In and Out on it.

Here's the RJ45 mic/accessory connector pin out from Motorola:

To make the programming cable, you need to build a RJ45 modular plug to DB9 or DB25 (depending on which is easier for your computer's port) cable. The pin out for the cable should be:

Connecting to a GM300

First, you need to program the GM300 accessory connector for remote instead of public address. Then verify that the jumper JU551 is IN so that you get flat discriminator audio on pin 11.

Other than that, use caution. Is that remote local, DC, or tone? If it is not local then a remote adapter is needed. If it is a local, then the rest is very simple. Connect RX HI from the remote to pin 11. Connect your PTT and MIC HI (pins 3 & 2). Next connect your grounds, MIC LO, RX LO, and remote ground to pins 7 & 9 or the power supply's ground. Then connect your 12v+ to the remote. It is not recomended to connect the remote's 12v+ to the radio, but instead to the power supply. This has a tendency to blow the internal fuse of the radio.

Good luck. And use your service monitor to adjust the remote.