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.
----- Original Message -----
From: "Joe Subich, W4TV" <firstname.lastname@example.org>
Sent: Monday, April 26, 2010 7:35 PM
Subject: Re: [TowerTalk] AV-640 (was GapChallenger ComparisonTesting
> 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.
> ... Joe, W4TV
> TowerTalk mailing list
TowerTalk mailing list