CB Experts-Need Help

I have a Uniden 980SSB with 18' of coaxial cable running to a Firestik Stud Mount and Antenna. The coaxial is straight with no loops or cuts to the cable. I had it tuned so that Ch.1 and Ch.40 had a SWR of 1.0. Then suddenly, it quit working, even NOAA. Diagnostics revealed that both the antenna and RF out failed.

Figuring that it was a bad stud, I replaced the stud and NOAA now works and I pass the RF out test. However, the antenna still fails. I show a SWR of 6.50 on Ch.1 and 8.50 on Ch.40. I've cleaned the area to get a good ground. I've also added a chassis ground near the stud but nothing I do changes the SWR. I've even tried different antennas but everything I do fails to adjust the SWR.

 

Sounds like it could possibly be a bad connection in your coax. Even though everything looks fine you could have a break in a connector. You have a dummy load you could try?