Well, Jim. Then it may just be a matter of semantics.
You see the AV-640 as a Windom, I see it as a 3/8 wave Marconi monopole (
vertical ) with elevated radials. And since it is 3/8 wave, it has a high
impedance at the feedpoint which requires the matching balun.
Most importantly, the radiation patters are markedly different between the
Windom of any sort and the AV-640.
The Windom pattern looks like a Chrysanthemum Fower ( almost
omni-directional ) and the 640 is a very low angle radiator without the
additional lobes.
Dan Schaaf
K3ZXL
"In the Beginning there was Spark Gap"
www.k3zxl.com
----- Original Message -----
From: "Jim Hargrave" <w5ifp@gvtc.com>
To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Sent: Monday, April 26, 2010 7:41 PM
Subject: Re: [TowerTalk] AV-640 (was GapChallenger ComparisonTesting
Studies)
>
>>> So far, I have outlined several differences between 2 types of Windom
>>> and
>>> the AV-640, enough to justify NOT calling it a Windom.
>
>>> Wouldn't you agree?
>
>
> Dan,
>
> I pass. I have never owned an AV-640, so I cannot offer a qualified
> opinion.
>
> I only pointed out that an antenna that is off center fed is commonly
> referred to as a "Windom". We normally think in terms of horizontal.
> However, I see no reason the same principal could not be applied
> vertically.
>
> Perhaps I should start calling my 17M antenna a "Vertical Windom"
> Its a 1/2 wave vertical consisting of a 3/8 wave whip mounted 6ft above
> the
> ground
> on a steel pipe. Its fed at the top of the pipe (base of the whip).
> I use homebrewed link coupling to a 50 ohm coax.
>
> Since it off centered fed, I guess it the meets the same principal...
>
> 73 de Jim
> W5IFP
>
towertalk
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