FS: Motorola Squelch Gate Modules for MSR-2000 series Repeaters. This
is a plug-in card assembly that goes in the MSR-2000 control card
cage. It provides a COS (Carrier Operated Signal) to key the
transmitter when a signal is received by the receiver in the repeater
station.

Available are one each: model # TRN5331A and a model # TRN5324A. The
TRN5324A has the optional relay mounted on the board. Adjustable
controls on both for Repeater Squelch Key level and Repeater Level
(audio). $75 each plus $5 postage.