On Fri, 29 Aug 2008 14:58:44 -0500, Tim N9PUZ wrote:
>what is a
>good technique for attaching to the tree trunk? Screw eye into
the
>trunk itself? Some sort of belt type affair around the trunk?
All of my antennas are hung in tall trees -- redwoods, Douglas
Fir, madrones -- so I've researched this issue a lot. The
executive summary is that screwing a eye or hoot lag bolt into or
through the tree trunk is the least invasive for the tree, and is
the method of attachment recommended by tree experts. It's also
the most expensive, because you've got to hire a climber to get it
there.
I also endorse the use of marine pulleys and a good counterweight.
Some have used old window weights. My antennas are up higher, fed
with RG11, and are rather long, so I need about 100# tension. I
bought 6.5 gal water jugs and filled them with dry sand (roughly
1.5x the specific gravity of water). I also try to use very robust
construction techniques. #10 copper, either bare or insulated THHN
(house wire) and the most robust center and end insulators I can
find. I use the 5/16 inch rope that DX Engineering sells.
W3DQ found a product called a Cambium Saver. It's a fabric
sleeving system that fits over a big branch. He described it in a
very nice presentation he did at Visalia this summer. It's an
alternative to the lag bolt/screw method, and can be pulled up
with a rope that you have launched into the tree.
73,
Jim Brown K9YC
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