[amsat-bb] FT-847 Serial Port Communications

I have a problem involving the 9 pin serial port on the back of my FT-847 Yaesu transceiver. When I try to use a null modem cable between the rig and my PC on either COM 1 or 2, the rig will not respond to compatible rig controller (CAT) nor a memory management program. The COM ports have been tested as well as the use of two different PCs. Neither null modem cable works. I have tried to use the Menu feature on the FT-847 to match baud rate between radio and PC COM port. Has anyone had a problem like this with the Yaesu FT-847? I would appreciate knowing.

Thank you.

Gary N0EZH