Topband: Guy line affecting SWR/match

[Raymond Benny]

All,

I have a situation that I have not encountered before and do not understand
the cause. I am building an 80m 4 square TX antenna system. I put up the 4
- 65ft irrigation pipe verticals between Sept and November when the
ground/earth was quite dry. I installed 48 - 67ft radials on each vertical.
At the time I resonated the vertical to 3.640kHz. Using my AA55 Antenna
Analyzer, X=0 and R was around 46 ohms.

Because I have not dug the trenches and laid conduit for the Comtex control
cable, I am feeding just one of the verticals so that I can get on 80m.
This has worked fine, SWR 1.2:1,  until we started having our winter cold
and rain/snow weather. The SWR is now near 4:1, and if I remember, the
vertical is resonant at above 3.8 kHZ, the R & X  have changed too, but I
have not measured them recently.

I am at a loss as to what is causing this change There are 3 or 4
thoughts/questions I have as to this situation:

1, I am using Dacron, non-conductive cord at three points to guy the
verticals. Top guy is about 10ft from the top. It seems that about the
start of our winter rains, the SWR and all changed. The guy lines are
attached directly to the vertical with a thimble, no insulators. Could the
wet guy lines be creating a leak to ground? I am planning to install egg
insulators at the guy points very soon, depending on the WX.

2. Could the ground conductivity and therefore the matching have changed
because of the rain? I am direct feeding the vertical with a K9YC 1:1:
toroid balun at the base. The ground here is a mix of typical soil: dirt,
small rocks and hard clay. When I installed the verticals, you could only
dig about 4 - 6 inches without much effort - there is no moisture in the
soil. With the rains, I can dig about a foot without much effort. The
ground below about 2 - 3 ft has not seen moisture since it was laid
down eons ago.

3, All  radials for the 4 verticals are lying over each other. I did not
trim or solder the radials together where they cross. The radial layout is
the same as before our rains.

4, I detached the coax at the base and placed a 1500 watt dummy load to it.
There was no reflected power.

As a note, for almost 8 years I had the single 72ft irrigation pipe
vertical with 4 - 30ft top hat loading wires for 160m. Also, I had a 65
foot drop wire spaced just 16 inches from the main vertical for 80m. I used
the same radial field, and had two separate coax and matching inductors at
the base. I did have to ground the main vertical (160m) in order for the
80m section to work properly.  All worked well and I did not see the effect
as mentioned above during those 8 years.

So I'm stuck for an explanation and a remedy for my situation.

Any thoughts, comments or suggestions?

Ray,
N6VR/W7YA

PS, Please excuse me for posting this on the Top Band reflector, but I
think there is more knowledge and experience on this site than any other.

Near Prescott, AZ
Nice rural, quiet location,
On 5 acres at 4800 ft elevation,
Winter low temps can vary from 15 to 35 degrees, with light rain and snow.