Interfacing the Paccomm TNC NB-96 & PSK-1 satellite combo to the FT-847

Updated 10 September 2000

There's and error on Page 4 of the of the PSK-1/PSK-1T Instruction Manual (Second Edition, First Printing - December 1991) where pins 6 and 7 of J1 (Main VHF Radio Connector) are the wrong way round. The circuit diagrams are correct.

I also found recently that as the RF is increased on the FT-847, the TX audio to transmitter (J1 pin 1) goes more and more negative on 1200 so I needed a 0.01uF capacitor to block the DC.

You don't need Pin 6 of PSK-1 J1, or any of PSK-1 J3 if you're using a single full duplex radio - which you are if you're using an FT-847, IC-820, IC-821, FT-736 etc. This is called 'JOINT' mode in PSK-1 teminology..

I also built a switch box to do all the necessary switching and connections between the PSK-1 and the FT-847:

SW1 is shown in 1200 bps mode, and SW2 is shown with track off.

Mail Howard, G6LVB