What connector are you feeding the audio into? The book says that the front mike is disconnected win digital. Perhaps the audio signals are not going into the proper pins?
Does it work on WSJT-X?
1 DATA IN Input terminal for data transmit. (1200 bps: AFSK/9600 bps: G3RUH, GMSK)
2 GND Common ground for DATA IN, DATA OUT and AF OUT.
3 PTT P PTT terminal for packet operation. Connect to ground to activate the transmitter. When grounded, microphone input (pin 6) of [MIC] connector will be disconnected.
4 DATA OUT Data out terminal for 9600 bps operation only.
5 AF OUT Data out terminal for 1200 bps operation only.
6 SQL Squelch out terminal. This pin is grounded when the transceiver receives a signal which opens the squelch. ? To avoid interfering transmissions, connect squelch to the TNC to inhibit transmission when squelch is open. ? Keep RF gain at a normal level, otherwise a “SQL” signal will not be output
