Just last week, I replaced the DXE ladder line (a maintenance headache, as
Hardy notes) in my two bidirectional 720 ft beverages with WD-1/TT field
telephone wire (the twisted pair version of WD-1), running both strands of
the twisted pair for each leg of the beverages. The wire is fabulous stuff,
with four conductors of tinned copper and three steel conductors in tough
wx-proof PVC insulation. I supported the wire every 60 ft with 4x4 wood
posts by threading it loosely through two porcelain screw-in electric fence
insulators atop each post. The insulators are widely available on-line
(Tru-Value Hdwe, Home Depot, etc.) and cost about $1.50 each. The holes have
smooth sides and I don't expect any wire abrasion.
The wire was attached only at the (back-guyed) end posts with roughly 75-100
lbs of tension, the tension in the parallel wires was equalized with a
pulley at one end. The spacing between the insulators was 50mm. The wire
(bought from eBay) cost $50 (shipped) in 1/2 mile lengths in canvas
dispensers. Attached are photos of the key parts of the installation.
I've not run quantitative tests of the performance, but subjectively it
appears the same as with the ladder line. I didn't change any of the
switching or matching transformers from those supplied by DXE. The F/B ratio
varies with time of day and the distance of the received station, but is in
excess of 20dB on 1.8MHz for JA stations in the morning. The antenna is very
quiet, and I can easily copy stations I can't begin to hear on my
transmitting vertical or my 80m inverted vee. I feel quite good about the
mechanical benefits of using the field telephone wire instead of ladder
line, and am confident it will wear much better. I've had a few strong winds
(40mph) in the past week and it barely waves in the wind.
73,
Jim W8ZR
> -----Original Message-----
> From: Grant Saviers [mailto:grants2@pacbell.net]
> Sent: Thursday, May 01, 2014 1:39 PM
> To: Hardy Landskov; Mike Waters; Jim Garland
> Cc: topband
> Subject: Re: Topband: Beverage wire question
>
> Is there any advantage to open wire line construction vs the
> bidirectional coax Beverage that ON4UN describes? RG6 is cheap and
> strong with a copperweld core or use any other coax from CATV surplus to
> RG58/59. Some are UV resistant, flooded, etc. The only downside I see
> is two transformers and two feedlines are required and perhaps a db or
> two loss for the reverse direction, which really doesn't matter. A plus
> is no relays. A coax version sure is simpler to build and maintain. Of
> course coax doesn't have the classic Beverage look ;-)
>
> Grant KZ1W
>
> see also http://w4hod.org/K4IQJ%20Beverage%20Talk.pdf for other
> alternative designs.
>
>
> On 5/1/2014 8:12 AM, Hardy Landskov wrote:
> > I've used window line for many years and it is a maintenance hassle.
> > The heat and UV here in AZ just eats the stuff up where it has to be
> > replaced every 5 years or so, and I do twist the line. The last wind
> > storm we had ripped the line right out of the DXE black plastic
> > insulators which are not all that good either.
> > So I am looking with keen interest at all these homebrew
> > open-wire-line construction techniques.
> > YMMV.
> > 73 Hardy N7RT
> >
> > ----- Original Message ----- From: "Mike Waters" <mikewate@gmail.com>
> > To: "Jim Garland" <4cx250b@miamioh.edu>
> > Cc: "topband" <Topband@contesting.com>
> > Sent: Wednesday, April 30, 2014 7:39 PM
> > Subject: Re: Topband: Beverage wire question
> >
> >
> >> Jim,
> >>
> >> On Wed, Apr 30, 2014 at 10:41 AM, Jim Garland <4cx250b@miamioh.edu>
> >> wrote:
> >>
> >>> I've been using 450 ohm ladder line ... and the ladder line requires
> >>> constant maintenance.
> >>
> >>
> >> I've heard that twisting that line solves the breakage issues. You need
> >> many twists in the entire length of the line.
> >>
> >>
> >>
> >>> I want to replace it with parallel wires, which run through ceramic
> >>> feedthrough insulators
> >>
> >>
> >> And, I've heard that running wire through ceramic insulators like
> >> that will
> >> eventually abrade the wire. Holes in ceramic insulators are usually
> >> quite
> >> rough.
> >>
> >>
> >> I have no experience with either of the above. Here, we use plastic
> >> electric fence and homebrew plastic insulators; and the wire drops
> >> into a
> >> slot instead of having to string it through a hole. Works for me.
> >>
> >> I think there's some photos at
> >> http://www.w0btu.com/Beverage_antennas.html .
> >>
> >> 73, Mike
> >> www.w0btu.com
> >> _________________
> >> Topband Reflector Archives - http://www.contesting.com/_topband
> >>
> >
> >
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> >
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