INADVM - DB9 Pinout 1 - N/C on REV1 - solder pad/hole on REV2 2 - TXA 3 - Squelch / DCD 4 - N/C on REV1 - RSSI on REV2 5 - PTT 6 - RXA 7 - N/C on REV1 - solder pad/hole on REV2 8 - GND 9 - N/C on REV1 - solder pad/hole on REV2