As I learned recently (thanks to Jose for the explanation) there is a conceptual / design difference between VARA_FM and VARA_HF. VARA_HF will accept PTT commands from VarAC. VARA_FM requires a direct PTT, as shown in the setup screen shots above. On FT-991 USB link we have the ENHANCED virtual COM: port, which takes care of both tasks: CAT and PTT. And it is not possible from Windows side to share the COM: port between VARA_FM and VarAC. The way out seems to be setting the VARA_FM PTT source to VOX, thus leaving the COM: port entirely to VarAC. I tried this recently, and it was possible to connect to a correspondent, but the connection automagically failed (disconnected itself) after 30 seconds. Broadcasts went OK both ways. I have not seen any error messages in VarAC log window. I have no clue yet why the VarAC connection failed to continue. Use of VOX for PTT looks to me like opening a can of worms. We have the issues of VOX sensitivity (level of audio signal from computer, generated by the radio sound card), switchover delays etc. The other way round is to assign the VARA_FM source of PTT to CAT, and disable CAT control entirely on VarAC side. Not very smart, but maybe this will work? Irad, can you pls comment? Best regards, Marek SP5ISZ

Thanks, Irad for the advice. It was set to USB, exactly as all screen shots for FT991A in the manual show 😫. A word of explanation there might be helpful. Hope this will bring the issue to resolution. 73 Marek sp5isz

Albert, Great to see that somebody replied. This problem puzzles me as well. To add some more info: when I send beacons, they seem to go OK (PSK Reporter shows this). The problem shows when I try to reply to somebody's CQ. The radio goes to USB, the PTT switches it to TX, but the output signal is none, because entry from mirophone is expected. I do not understand which file you refer to as the "COM". The CAT commands file is V13, the VarAC is V8.4.4, the Windows version is 10. I am suspicious of one entry in VarAC INI file (see attached picture). It states that the USB mode should be USB, rather than e.g. DATA_U. I will be happy to replace this in the INI file, but I do not know how the DATA_U mode is called in the program vocabulary. 73, Marek sp5isz