W4RFR/R 145.11 Repeater Operations - R303/TD-5 installation Installation of the Hamtronics R303 and TD-5 units. R303 technical sheet TD-5 technical sheet Prototype in the shack. Current recever, RCA antenna connector silver RCA to upper right on top of wire harness chicken nest. Wiring to SCOM DB-25 clock-wise from bottom. Note pages refer to the 7K operations manual (see below for direct links). Red, Tx PTT, DB25-10 Black, Tx audio out, DB25-14 Green, Rx COR/COS, DB25-2 pg C3-4 Blue, Rx CTCSS decoder, DB25-5 pg C8 White, Rx audio in, DB25-1 pg C6-7 Shield/Silver, Ground, DB25-20 SCOM 7K DB-25