6BTV 80 Meter Resonator issue

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.