Problem: The resonant spot for 80 meters on my 6BTV had moved. In other words, the antenna no longer resonates in the 80 meter band.
Prolonged Investigation:
- After a rain event I noticed the resonant spot for 80 meters on my 6BTV had moved.
- A few days of sunshine and everything was back to normal.
- Next rain event, the problem came back.
- I waited for a few more days of sunshine and a return to normal operation.
Steps to resolve:
- I took down the vertical
- I taped the resonator where the top and bottom caps touch the coil.
- I re-installed the resonator and tested to be sure it was tuned where I wanted it to be in the 80 meter band.
- I put the vertical back up in its normal, operating, position.
Testing the fix: Another rain event occurred a few weeks later. After the event I check the antenna and it is still resonant where it is supposed to be in the 80 meter band!
Conclusion:
- Water from the rain was infiltrating the resonator, moving its resonant spot.
- After a few days of sunshine the water was gone and the resonator worked correctly.
- Taping the resonator adequately sealed the resonator from the rainwater.
