I use military WD1A telephone wire which cost almost nothing but UPS for a 1
km unused reel.
At 500-750' for Beverages the extra RF loss tilts the wave more and and has
excellent directivity as 2 wire reversibles. I use black electric fence
insulators into trees at convenient intervals and the wire slides thru them
and have removed many large limbs after storms with no breakage. The wire
looks like a sine wave with maybe 2' between peaks and valleys. Both ends
use rope around trees and insulators made from soft delrin rod with a few
holes drilled to loop the wire thru in 3 very loose passes. After a couple
of storms I take up some slack and get ready for some more limbs bouncing on
the wire. Nothing broken going on the 4th year now for the oldest one.
I suspect that the telephone wire, and galvanized fence wire would work well
over salt marshes and other places of very high ground conductivity to add
wave slope AND directivity.
Carl
KM1H
----- 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
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