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.

Installing a 6BTV in the backyard

 And this is what it looks like!  But it was not always this way.

In the beginning I picked a location in the middle of the backyard.  At first I considered installing a nice piece of heavy pipe in cement to which the antenna would be attached.  But I thought, what if I don't like it?  Or move and it has to be removed?  

The solution was to put a PVC pipe in the ground in cement, with the top of the cement below ground.  That way, should I need to remove the antenna, I can simply cut the PVC off below ground level and fill the hole with dirt!

A loop of 10 guage wire encircles the PVC pipe and the radials are soldered to it. 

A 3 foot piece of galvanized fence post is slid into the PVC and it will hold the antenna!

The odd furrows in the grass were made with a weed eater on its side.  Into these the radials were laid and held in place with lawn staples from Lowes.

After everything was hooked up. The radials, ground rod, lightning arrestor and coax.  The rocks were placed to make it look nice in the yard.

The Coax and ground wire go from the antenna to the box mounted on the outside wall of the house.  Here we have another lightning arrestor and ground rod.  From this box we have coax going into the attic.  Yes, there is a second coax pull from the box to the ham room... for future stuff....  

The ground wire and both coax were brought into the ham room through the attic and wall.  This is behind the door.   When the door is open, you do not see this entry point.

Last, the trim plate is installed for a cleaner look.

And it works!  Tuning of the vertical will be looked at in a later post.