This is a simple add-on adapter for any Family Radio Service (FRS), amateur, or two-way radio transceiver with a microphone/Push-to-Talk (PTT) and external earphone/speaker interface.  It will turn the transceiver into a co-channel jammer.  That is, a jammer which can only jam a single frequency upon the detection of any “activity” on that particular frequency.  This type of circuit is also commonly referred to as a Carrier Operated Relay (COR).  This is the perfect type of jamming system to interfere with those pesky Best Buy & Wal*Mart security guards, restaurant drive-throughs, and also LoJack and cellular/pager-type “quick bursting” radio transmission systems.

Schematic: GBPPR JAMCAT Schematic

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