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Date: Fri, 12 May 2006 21:58:23 +0400
From: Ed Lesnichy <ed@dx.ru>
Organization: Ed Lesnichy
Message-ID: <1779031882.20060512215823@dx.ru>
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Subject: Re: LF: Rope?
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Mike and LF enthusiasts,

12-05-2006, 20:33 MSK(+3 GMT), G3XDV wrote:

MD> I am refurbishing one of my antenna supports. It is supported by a
MD> large tree and is raised and lowered using blue polypropylene rope
MD> (from B&Q).
I use polypropylene rope for all Big TX Verticals since spring of 2002
(on LF DXexpeditions to UA9-UA0 also) - rope diameter from 3 up to 5mm
with a copper wire from 0.5 up to 2mm on rope
Length of a rope of the aerial sometimes achieved 400 meters

MD> The rope shows signs of deterioration - presumably from UV - and I
MD> wonder whether I would be better using white polyprop, or nylon, 
MD> rather than blue polyprop.
My first aerial with 5�� (abt 400m long from 135m tower to 8m down)
of a orange polypropylene rope has sustained 3 years (3 winters).
I believe that the main enemy for polypropylene rope is UV and
the durability of a wire is not influenced by his colour (I used also
blue and white ropes also made in Turkey or China)
Though in R6L there is one more enemy - look last photo of my 5mm rope on
http://136.73.ru/news/2005/jan/black.htm

MD> Nylon is a lot more expensive - is it worthwhile? I understand than
MD> nylon is stretchy - is this a problem? Does nylon have a similar 
MD> breaking strength - the antenna is lightweight but takes some wind-
MD> load and in any case I don't want any accidents, so over-engineering
MD> is the order of the day.
Nylon or kapron(I do not know as is precisely written on english) resist
to UV better, but have the greater lengthening at loading at an identical
diameters
I believe best to apply an aramid rope (2..3mm - identical KEVLAR Du-Pont),
but it very expensive
2mm aramid rope - 290kg break - 4% - abt 0.5USD/meter in RU

73! Ed RU6LA  http://136.73.ru