[AMRadio] Seeking advice on "wires in trees"


D. Chester k4kyv at charter.net
Wed Apr 29 12:35:54 EDT 2009


I would never use a pulley, springs or weights.  Use some good, heavy duty 
UV-resistant rope.  Instead of a pulley, use a medium size "johnny ball" 
strain insulator, like you would use on guy wires.  Don't use the smallest 
size. Attach the insulator to the rope that goes across the limb, just as 
you would a guy wire, and securely tie the  rope.  Then run the rope that is 
attached to  the end of the antenna through the hole.  Pull the first  rope 
until the insulator is just a few inches over the limb and firmly tie it 
down.  Now pull the antenna rope, letting it slip through the hole in the 
insulator until the antenna is as tight as you can get it.  If you leave 
too much slack and sag, it will bounce all over the place and likely shake 
itself apart in a windstorm, and sometimes the feedline can manage to tangle 
itself up with anything else it can.

The insulator has no moving parts, and if the  ropes are inserted properly, 
about the only thing that could go wrong would be to break the insulator, 
which is unlikely since they are  designed to handle at least 3000  lbs. 
The rope just slips through  the hole over the glazed porcelain. Pulleys 
have a bad habit of freezing up over time, or the rope derails off the 
groove at the edge of the wheel and manages to bind between the side of the 
wheel and the frame of the pulley. Or the whole thing rusts over time and 
falls apart.

The spring is even a worse idea.  If it doesn't stretch out in a windstorm, 
it will very quickly  rust in two and break.

The rope over the limb should not be able to slip back and forth.  That will 
wear the rope in two and cause chronic damage to the tree as well.  Better 
to let the tree limb grow over the rope with time, and use the insulator for 
the antenna rope to slip through.

Generally, it is a bad idea to tie the rope or wire  round a tree limb if 
that can possibly be avoided.  This may eventually cause rot to set in and 
you lose the entire  limb or even the tree.  If you can climb up to the 
point of attachment, a better idea is to get  a hot-dipped galvanised (not 
zinc-plated) threaded eyelet with about a 1/2" diameter threaded rod and 
about 3" longer than the diameter of the limb, drill a slightly larger hole 
all way through the limb, insert the eyelet through the hole, and secure it 
in place with galvanised washer and two nuts.  Use the first nut to hold the 
eyelet, and use the second nut as a "pal nut", torqued down tightly against 
the first one, to avoid the possibility of the first nut managing to unscrew 
itself from the eyelet.

They also make eyelets with a shank like a wood screw, which will work if 
you can get them screwed most of the way through the limb, but that may be 
easier said than done.  I have found it easier to pierce a hole with a 
cordless drill and use the nuts and washer method of attachment, especially 
while hanging onto a tree limb at  40-50 ft. in the air.  A good climbing 
belt is highly recommended.

When I  had my antenna in a tree, I could climb to where it was attached, at 
both ends.  I had better luck using #10 copperweld wire for the antenna, 
good *heavy duty* insulators, and attaching the antenna rope directly to the 
tree, pulling it as tight as I could, and permanently fastening each end so 
nothing was slipping through anything or over limbs.  During windstorms, the 
antenna would actually hold the limb stationary and the feedline would 
bounce around less.  That antenna stayed up at least 5 years before I had to 
re-do it.  With rope looped through the insulator or over the limb, I  could 
count on putting the antenna back up after every heavy windstorm, at least 2 
or 3 times a year.  But flimsy wire and/or antenna rope will break.

Don k4kyv



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