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[Towertalk] 80M 4 Sqr resonant point jumps way high...any ideas why?

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Subject: [Towertalk] 80M 4 Sqr resonant point jumps way high...any ideas why?
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Date: Sun, 11 Aug 2002 13:27:30 EDT
I use a comtek systems hybred coupler with 4 1/4 wave top loaded verticals in 
an 80 meter array.  Testing the system out before the winter season, I've 
found that the array's resonant point has jump 400KHz to apprx 3.990MHz from 
where each individual antennas are tuned at +- 15KHz at 3.600MHz.  The array 
has always jumped 200KHz, over three rebuilds, using various lengths of 
verticals and top loading wires.  So this major jump on the surface is 
unexplained.  In looking over the array, I have decided to replace the 
feedline connections as some were getting weathered.  I also recently put up 
a 4 foot tall 3,800 foot goat wire fence on the west side of the array just 
past the 1/4 wave ground radial field.  Could this be the culprit in all of 
this.   I am wondering if anyone with a 1/4 wave vertical array has ever 
noticed such a change and if so, what caused it-.  In my research, I have 
found most arrays constructed like mine jump around 100KHz from where the 
individual antennas are tuned due to interaction inside the array, phasing, 
and factors in the environment.  The explanation for mine originally going up 
200KHz was that it was in the clear without anything around it- And it worked 
great!  Now a simple fence is causing it to jump 400KHz???? Can't be that 

It's either the 1. Fence  2. Feedlines are screwed up   3. Comtek Box problem 
 4. One of the verticals is screwed up but this has been ruled out- 5. Your 
suggestion here??  

The F/B is down a bit, no matter where I am on the band-  

73  Paul  N0AH/7

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