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[TowerTalk] L.G. Windom

To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Subject: [TowerTalk] L.G. Windom
From: "Paul Christensen" <w9ac@arrl.net>
Reply-to: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Date: Mon, 26 Apr 2010 20:17:37 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I had a bit of difficulty locating the original article from Loren Windom. 
It's in the September, 1929 issue of QST (re-printed Dec., 1966) and is 
entitled "Notes on Ethereal Adornments," and sub-titled " Practical Design 
Data for Single-Wire-Fed Hertz Antenna."

The article begins by giving credit to three others, all associated with 
Windom through his academics -- then goes on to discuss the attributes of 
the OCF antenna.  Definitely an interesting read.

Paul, W9AC






----- Original Message ----- 
From: "Joe Subich, W4TV" <lists@subich.com>
To: <towertalk@contesting.com>
Sent: Monday, April 26, 2010 7:35 PM
Subject: Re: [TowerTalk] AV-640 (was GapChallenger ComparisonTesting 
Studies)


>
> On 4/26/2010 6:44 PM, Dan Schaaf wrote:
>
> > And the antenna book also mentions that the single wire feed Windom
> > produces RFI in the shack and it works against a ground. And the
> > single wire feed line also is a radiating element.
>
> The ARRL Antenna book is wrong in that regard.  The whole design of
> the original antenna that Loren Windom reported on was to solve
> the RF in the shack issue by matching the impedance of the single
> wire feed to the impedance at the connection point.  This made the
> single wire a "flat," non-radiating line.  If the single wire, off
> center fed antenna had any significant RF in the shack or feed line
> radiation, it wasn't a Windom in your definition of the term.
>
> > But definitely not a Windom as it was originally designed with a
> > single wire feed and no break in the horizontal wire.
>
> The presence or absence of a break at the feedpoint is not material.
> If the single wire fed "Windom" is operating as a true "Windom"
> with a flat (non-radiating) feedline, the operation antenna pattern
> is identical to a parallel wire fed or coaxial/balun fed "pseudo-
> Windom" as long as the feedline version is also operating with no
> unbalance current.  Even in the "real world" where none of the
> "Windom like" antennas operate with truly non-radiating feedlines,
> the levels of feedline radiation and RF in the shack are similar.
>
> > And my AV-640 does NOT provide RFI in the shack.
>
> You AV-640 does not provide RF in the shack because of the large
> current balun (also known as a common mode choke) located in the
> "matching unit."  The ability to use a common mode choke is a
> major advantage of converting a Windom type antenna away from the
> single wire feed.
>
> 73,
>
>    ... Joe, W4TV
>
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