To get sufficient space between the tag lines, yet allow them to be untied
from the center is simply a matter of tying the knot in the center and
running it out along the boom and then dropping it over an outer element and
down to the ground. You need to make sure the rope will not pinch between
the element and the boom. A stiffer/slippery rope like cheap yellow poly is
a good choice since the free end won't whip as badly and is less likely to
tie itself into a knot (hitch) around something. If you are concerned about
it catching, just let the tower guy hold onto the rope before he unties it,
the whipping action will be much more controlled....
----- Original Message -----
From: "Pete Smith" <email@example.com>
Sent: Monday, February 23, 2004 20:54
Subject: [TowerTalk] Quickly releasable knot
> This past weekend I was on a ground crew putting up two large 40m
> yagis. Because the tag lines needed to be reachable from the tower, they
> were attached only maybe 18 inches from the center of the boom, which made
> it very hard to apply enough force on the tag lines to control the antenna
> (lever arm too short).
> I seem to recall reading, at one time, about a special type of knot
> designed for remote untying. In a nutshell, it holds tight as long as the
> "untying" force is applied through the loop formed by the knot, but a good
> tug on a "pigtail" sticking out of the knot itself will cause the knot to
> untie. It occurred to me that such a knot could have been used to attach
> the tag lines some distance from the center of the boom, with the pigtail
> taped to the boom and long enough to reach to the center, so that the tag
> lines could be released when no longer needed.
> Am I making this up, or does someone know the details or, perhaps, a web
> site source?
> 73, Pete N4ZR
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.
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