I recommend tarred nylon twine. See photo at
http://www.dutson.net/transfer/HamRadio/IMG_0664ds.JPG
This is the 440lb size. We used it during the VP8WWW DXpedition last
November to hold up a Moseley mini33 on a military mast. We decided to use
two strands because of the notorious high winds in the Falklands. One day
the winds exceeded 50mph causing the elements to bend back almost 90
degrees. We expected failure of the guys but all came through without a
problem.
I also have used this at home to hang wire dipoles from trees. I recently
took down one of these (80m) after 6 years and the twine is still good with
no apparent wear.
This twine is sold in my area at Academy in the fishing supplies section.
It is marketed as trot line.
73, Keith NM5G
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Friday, October 14, 2005 2:49 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Antenna Rope report
More comments from my experience over a couple of years.
I bought several thousand feet of the very nice black sheathed dacron rope
(with a white center) sold by Davis RF (and others). I installed about half
of it at W6BX, hanging wire dipoles between the top of the tower and ground
stakes. I also used some of it at home.
The rest has not been used. My observations are:
1. Moderate sun bleaching over a period of two years.
2. This rope does not hold up to being run through pulleys or over anything
that can cause wear. The two biggest wires at W6BX both fell to the ground
after the rope broke at the top. One fell in less than a year, the other six
months later. Note that this is a mountaintop QTH (see qrz.com) that gets
fairly high winds. I note similar wear at the home QTH.
3. Generally nice handling characteristics.
Conclusions: This is nice rope, but I wouldn't use it anywhere that it will
be subjected to any form of wear, and I would expect the sun to cause
failures after 3-5 years, depending on the weight being supported. At W6BX,
we've replaced the upper rope/pulling rigging with Phillystran. We're still
using the rope on the bottom ends, which are not subject to the wear.
A parallel observation regarding the super flexible, finely stranded copper
being sold by Davis RF as antenna wire. While it's "nice," it doesn't hold
up at all. Some wires at W6BX that used the #12 version fell apart in less
than 6 months. The strands break at the ends where they are tied off. Our
wires are now 3-wire parallel dipoles built using #10 solid copper for the
longest dipole that supports the weight and #12 standed THHN for the
parallel dipoles. All wire was purchased at Home Depot. We "hard drew" the
#10 by tying it between the towing hook of our truck an a telephone pole.
There have been no failures of these antennas so far.
I'm also preparing for a move to CA, where I will be rigging lots of wires
from lots of redwoods (we'll own 8.5 acres). I would appreciate advice from
those who have successfully done so, especially with respect to the support
ropes. I will have access to a local guy who climbs the trees and will
install pulleys (without damaging the trees). I may use the dacron rope for
the low end of sloping wires, but not at the top where it goes through the
pulleys.
Jim Brown K9YC
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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