6 FT-90R OPERATING MANUALMIC JackThis 6-pin modular jack accepts transmit audio, and provides 9600 bps datafor Packet Operation.Pin 1: SW 2 (multi-function switching)Pin 2: 9600 bps Packet Data Output(Impedance:10 kΩ Maximum Output:500 mV pp)Pin 3: +9VPin 4: GNDPin 5: Microphone InputPin 6: SW 1 (multi-function switching)Right Side ConnectorMIC Jack