Another RFI symptom to watch out for

KD0RC

Tonight on 20 CW using my Flex 6400 and KPA 500 amp, I kept getting disconnected from the radio. I had to hastily sign off and move to a clear frequency for testing.

I could reproduce the issue and noticed that the network quality indicator went from 5 green bars down to one bar when I transmitted. It took a few seconds to come back to normal after I stopped transmitting. This explains why I had no problems during Winter Field Day, but big trouble during a rag chew QSO.

I added mix 31 ferrites to the two CAT5 cables (non-radio related) that didn't yet have them - no help. Then I wrapped the cable to the radio through the ferrites at both ends twice, and that seems to have solved the issue.

So if I remember correctly, a second turn through the core increases the inductance by a factor of 4. Doing that at both ends of the cable makes quite a difference. Please let me know if I have this wrong.

So if you suspect RFI issues, take a look at the network quality indicator; it might just point you in the right direction.