How long it lasts really depends on how mechanically intuitive we are when
we install the antenna.
Key things are to let the wire float in everything but the end supports, and
make sure things don't cut, flex, or rip the wire apart. Spreading the end
load, if you grip the insulation, is a good idea. It is better to strip back
the insulation and egg insulator the ends with a rope that floats and allows
tensions to equalize between both conductors.
The wire also has to be supported to make short spans, so tension is not too
great.
Mine traditionally lasted for several years, although I'm not sure about
quality of new wire. I had some stranded window line where wires just rusted
apart in a few years.
----- Original Message -----
From: "Les Kalmus" <w2lk@bk-lk.com>
To: <topband@contesting.com>
Sent: Thursday, October 24, 2013 10:21 AM
Subject: Re: Topband: Beverage Woes
I use ladder line from the Wireman and from Davis RF. I think the
conductors are copper plated solid steel.
I bought 1/4" thick 2" wide strips of acrylic from McMaster Carr and made
a pair of clamps of 6" long pieces by cutting grooves for the wire
thickness, two holes for ss bolts and one for a rope.
These clamp the ends tightly and the acrylic is useable outdoors.
The ladder line is supported every 50 -75 feet by a 3-4" piece of pvc wide
enough to easily pass the ladder line and with a large and small hole in
it. The small hole is for a screw into a convenient tree and the large is
to pass the screwhead.
Where there were no trees, mainly a swampy area, I used metal fence posts
with a piece of pvc over the post with a bolt through limit how far down
it slides on the post and a T on the top end. The ladder line passes
through the T.
The supports are at the end only. The ladder line has a twist every 3 or 4
feet and rides easily through the pvc supports. This has been up for at
least three years and has survived tree limbs, frost, snow and people with
no problems to date.
I think I have pictures of the clamps if anyone is interested.
Les W2LK
On 10/23/2013 5:46 PM, Mike Waters wrote:
Whatever you use for wire, it needs to float at the supports. Anchor it
at
only one end and tension it tightly at the other end.
I use my own ladder line, made from .061" diameter plated steel electric
fence wire and spacers made from 1/4" dia. plastic coat hangers. Supports
are 10' high and 100' apart. It's taken a lot of abuse, including large
tree branches falling on it and a porch roof hurled against it by a small
tornado. Some supports broke during the flying porch roof incident, but
the
wires never broke either time.
WD-1A military telephone wire works well, if you have the right impedance
matching transformers.
Having said all this, I know that a lot of Topbanders use that brown
plastic window line for their Beverage antennas. Which kind lasts?
73, Mike
http://www.w0btu.com/Beverage_antennas.html
_________________
Topband Reflector
_________________
Topband Reflector
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: 10/20/13
_________________
Topband Reflector
|