[Antennas] Butternut HF6V Problem

[David C. Hallam]

Something has happened to my antenna.  The antenna is installed at 
ground level.  I have 2 - 4' ground rods at the base and 9 - 60' radials 
in the yard.  The antenna has been installed for over a year with what I 
consider good performance for a vertical and 100W.  I have a Rig Expert 
AA-54 antenna analyzer and measured 1.5 or VSWR or less on 5 bands.  
Since I did not have a rig which would cover 30M, I left the 30M coil 
setting at the length specified in the manual for the initial setting.

Recently I purchased a Kenwood TS-130S which does cover all the WARC 
bands from an estate.  So, I decided to adjust the 30M coil to try that 
band.  The antenna manual says that 1/4" adjustment of the coil length 
should change the resonant frequency by about 100 KHz.  I found I had to 
compress the coil by 1 3/4"  to get the VSWR to 1.26 at 10.130 MHz.  I 
did not measure the actual resonant frequency before I started making 
changes, but it was well above the upper band limit so that amount of 
adjustment was probably not out of line.  I was just surprised that so 
much movement was necessary.

The manual also states that a large change in the 30M coil may affect 
the 20M band also so I ran a scan on the other 5 bands.  I found no 
change in 80,40,15, and 10.  The VSWR on 20M was slightly higher than 
before, moved up in resonant frequency, but still OK at 1.5 at 14.175 
MHz.  However, now it is essentially flat across the entire band.  
Before the VSWR had been a little lower with a slight rise at each band end.

Now my problem:  My receivers, all 4 of them, are essentially deaf.  
It's about 13:00Z here.  I can tune across the 20 &15M bands with the SS 
contest going on and barely hear any signals.  I have a B&W coax switch 
in the feed line and did check VSWR before and after the switch with no 
difference noted.  I did not do anything to the feed line while working 
on the antenna.

I am going to go out in a little while and reset the 30M to the original 
setting to see if that makes any difference.  Since there are no 
reported solar flares that are affecting propagation, I don't know what 
to think.  I may try to readjust the 20M VSWR a little before changing 
the 30M coil.

David
KW4DH


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"We may consider each generation as a distinct nation, with a right, by the will of its majority, to bind themselves, but none to bind the succeeding generation, more than the inhabitants of another country."
Thomas Jefferson