Specifications

Technical Manual Installation and Operation
RELM/ BK RADIO
19
A dual directional coupler consists of coupled microstrip transmission lines fabricated
on the PCB artwork. The sampled RF energy is rectified to provide a proportional DC
voltage output.
The PTT signal enables the amplifier circuit by providing bias to the transistors. A
thermistor TS1, physically located on the PA heatsink monitors the heatsink’s
temperature and is monitored by the Micro Controller.