Thanks Kevin!
You are absolutely correct! It was RF getting into the computer/cable. After
experimenting some more after my post, I realized that I failed to reconnect my station ground after field day. So the RF was going to ground via the PC's AC power cord. Before remembering that I failed to reattach the station ground, I was able to correct the 40 meter FT8 issue by...lowering the power output to 35%. I could go back to 100% power after just unplugging the PCs AC power cord...no more PC path to ground!

Thank you so much for your reply Kevin and best 73s!

Craig
KB8AKZ

Sounds like RF from the rig getting to the USB cables & computer. Have you
started with a low power out (5 watts) to see if the problem is there?

Try increasing the spacing of your coax & USB cables.

Have you added ferrites to your USB cables?

Best regards,

*Kevin Potter *
*k5vp*

Hello!
Just downloaded ver. 2.5.4 and testing showed that it works on 20, 15 meters etc. but not 40 meters? Rig is an Icom 7300 controlled by a Dell PC.

40 meter FT8 receive initially performs as expected but when the transmission tries to start, the rig switches to the transmit frequency, tries to initiate a signal but fails and shows the rig control error. The rig is then receiving on what I believe is the offset transmitting frequency. Why does this happen on 40 meters and not the other bands?

Is there a problem with the correct offset frequency that I'm not aware of? I apparently retained and earlier version of the program when I downloaded the new one. Tried the previous version with the same result. Hmmmmm!

Well, I'd appreciate any suggestions as to the cause and the solution!

Thanks
Craig in Michigan