[Elecraft] Another "dipole" with a simpler tuner and feedline

[Kevin Rock]

You just described the antenna I take camping with me and my K2.  I have 
an ATU on the original top so it works nicely.  The flex weave makes it 
very nice for throwing up and taking down.  I can tie knots in the wire 
and they come out fine.  I tie a sheet bend to some mason's line and take 
a few 2 ounce sinkers to whip them up in the fir trees.  Or if I feel 
brave I swing the lead weight around my head and let fly.  Normally I can 
get it right where I want with that method.  Occasionally I have to duck 
rather abruptly.  Your mileage may vary :)  I designed the Windom to work 
on 80 meters so it takes a bit of string and two trees a bit further apart 
than your 20 meter version.  But in Oregon we have plenty of trees 
(outside of the clearcuts).  {Earth first; we'll log the other planets 
later :)
    73,
       Kevin.  KD5ONS


On Tue, 3 Aug 2004 21:47:01 -0400, Guy Olinger, K2AV 
<olinger at bellsouth.net> wrote:

> For a single band, there is an interesting old-time alternative called
> a single wire Windom. It is a horizontal halfwave with a single wire
> feedline connected to the horizontal wire off-center. For 20 the
> "dipole" part is 34 feet. The single wire feed is soldered to the
> horizontal at a point 12.5 feet from either end and drops to the
> ground.
>
> The wire is fed against ground. The single wire exhibits a 400-450 ohm
> feed against ground, regardless of the height of the height of the
> horizontal under 3/4 wavelength. The vertical part radiates very
> little. A poor ground that would ruin a vertical's performance at
> 20-35 ohms feed Z will do OK at 400-450 feed Z. As in a single 17'
> radial wire just laid on the ground.
>
> You can feed it with a unun wound on a toroid with a 3:1 turns ratio.
> SWR on the low Z side easily matches 50 ohms well enough for coax or
> any antenna tuner, without having to endure the high voltages found on
> an endfed halfwave.
>
> It has the predictable performance of a good dipole, without the
> center insulator, and without the weight of a coax feed. If you use
> something like flex-weave for all the wires it can be wound up and
> carried around.
>
> 73, Guy.
>
>
> ----- Original Message -----
> From: "Ron D'Eau Claire" <rondec at easystreet.com>
>
>
> I think it must have been self defense by someone. Some time back I
> gave up
> using the term "dipole" because the current crop of Hams seems to
> think that
> means a center fed antenna of some arbitrary length, rather than an
> antenna
> that is exactly 1/2 wave long and which might be fed anywhere.
>
> So I gave up and started saying that I had a half wave antenna fed at
> the
> center, or at the end or off-center, etc.
>
> But, since I like others to understand what I'm saying, I avoid
> acronyms.
>
> I take it the coupler at:
> http://www.qsl.net/aa5tb/coupler.html
>
> Is for QRP only! At 50 watts or so, I used to get flash-over in a wide
> spaced air variable in that circuit. I used  a large "Air Dux" coil
> with it.
> The voltages present at the end of a dipole are huge at any
> significant
> power level. I can't imagine the wire insulation on a toroid or a poly
> cap
> withstanding more than a few watts of RF there.
>
> Ron AC7AC
>
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