Thank you Kevin for your? suggestion. No, I don't have other terminal software as long as I remember on the main PC. I've tested the cable? on 4? different PC with the same? result. But on all 4 PC's , now that you are telling me that, I've a software called VAC, Virtual audio cable, that I use? for connecting an SDR? to PC for FT8 purpose. May be is interfering with Virtual Com port ?
In particular on 1 PC, the oldest still with Windows 8,? I? have very few? programs inside, and VAC is there. I? think I? will try to uninstall it and see what happen. Never know. Thnaks? again. Bruno
Bruno