R9 keeps going open. Any ideas. It's the center feed to the cap string. 5 ohm 10 w wire wound. I had switched from 75m to 20m and was loading when it went down the first time. I had 1450 PEP watts out on 75m SSB before I switches it. Then I was loading it on my Dummy Antenna and R9 opened. Help, Cam WA4JKW