Topband: suitable wire for top loading wires?

[Gary Smith]

I concur. Granted, my system for the inv-L is not ideal but it seems 
to work for me. I have dead bug radial base with 60 some 130' 
radials. Dead bug in that in the middle of the stainless plate is a 
hole and my Butternut is in there. There are two ground rods at 
either end of the radial plate. I also have my 160 Inv-L & 80M Inv-L 
shields attached to different radial bolts as well as a 40M & 30M 
verticals being attached the same way.

This plate is placed at the center of a triangle of three trees at 
the Marsh border (so I can get as many radials as possible on the 
salt marsh) I have a Dacron rope around each of the trees about 30" 
off the ground and pulled taut (This was originally to keep deer from 
wandering into the antenna). and to this end, it's been a good idea 
as I see deer tracks all around it but not within the triangle.

I made a spud gun as shown in QST and bought a larger valve and used 
larger PVC with a larger PVC "Spud". I have a large open faced 
fishing reel with short rod & eyelets that fit on the end of the 
barrel. 60 pounds of pressure from a tire pump and I can get the spud 
easily 100 feet over the tallest oak around. The spud has a loop at 
one end which attaches to the swivel at the end of the monofilament 
line. The thing is so accurate that I can always get that spud 
through a 5' of clear-sky opening in the trees without having to try 
again. Far better than a slingshot or bow & arrow for I'm using 30 
pound monofilament and the heavy spud pulls that line right through 
the trees where it falls and when I attach the rope to hold the 
antenna to the swivel & pull it through, it always goes through & 
over the trees without being snagged and the monofilament breaking. 
Truly a one step procedure.

So I aim the spud through that opening and so that it will travel 
over the tallest tree nearby and when it lands I attach the antenna 
wire (Cat 6 cable, soldered at both ends with a ceramic insulator at 
one end & eyelet at the other. I pull the insulator through the trees 
till the wire is tight.

BUT... at the feedpoint end, I see how much wire is needed to attach 
to the center of the coax and then make a loop knot (the simplest 
kind of knot where it would be a loop of wire except I run the wire 
through the loop) above the dacron rope that keeps the deer out. I 
also make a second knot loop which goes around the dacron barrier. I 
connect those two knot loops with a short piece of dacron so as to 
allow a bit of sag. I then attach a separate dacron rope through the 
loop knot which is on the barrier rope and then attach the loose end 
to the ground rod next to the plate. 

I shuffle things now so that if the antenna wire is pulled tight, the 
top loop pulls the dacron rope fixed between the loops without 
pulling the top wire sag totally tight and that the deer barrier rope 
when being pulled upward does not pull the bottom sag completely 
tight. What this does is allow me to always have the feedpoint 
elevated from ground but also prevents the antenna tension from ever 
pulling on the center conductor of the coax.

At the far end where the insulator is, I can't get a pulley up & over 
the trees so what I do instead is pull the antenna wire till it is 
taut (to be sure I have all the slack out of the wire) and then tie 
one end to the narrow end of a tree branch I cut down, it is 2-3" at 
the thick at one end and 1" at the other & is maybe 10' long. It lies 
loose on the ground. When I actually tie it to the branch, I loosen 
up the rope so it is not constantly pulling on the wire. When the 
wind blows the trees, the feed point never feels tension and the 
other end is allowed to pull that branch up if needed to allow relief 
and it always settles back to ground afterward, back to where I set 
it to be.

Every so often I check to see if the rope has settled more in the 
tree and if it did, I just take up the slack on that end tied to the 
pole.

I'm right on the coast with an open view to the ocean at one end of 
the cove and right at the marsh line where the winds are the most 
severe. I have only had to replace the 160M wire only once and that 
was after we had sustained 60 MPH winds for several hours. Using that 
spud gun, I had the new wire up, and finished in about 30 minutes. 

I know all that was kind of wordy but I wanted to explain everything 
so it would be easy to follow if someone else wants to do the same.

I forget which month that Spud Gun was explained in QST, it was 1-2 
years ago. I made one just like in the magazine but then I fiddled 
with the valve and made it a bit better. I then ordered a larger 
valve from Ebay. Either would work but I wanted a heavy duty version 
that would be sure to do anything I would ever ask of it. Minus the 
monofilament, that sucker would take down a deer at 300'...

73,
Gary
KA1J

> I think the key here is maybe not the wire so much, but the tree.  
I
> hold up an inverted L between trees, and the sudden stress of tree
> movement pulling a wire taut can be QUITE high. Would be very helpful
> to know the details of the tree suspension you are using to keep up
> your topload vertical, before proposing an improvement.
> 
> 73, Guy