[TenTec] [Ten Tec] OCF Antennas - Which commercial antenna is gest?
barry.n1eu at gmail.com
Wed Sep 23 10:26:06 EDT 2015
I've enjoying this discussion and especial kudos to Rick for his fine
efforts in R&D and his dx/contest results with the OCFD. Every time a
problem crops up with my rotor or SteppIR or myriad single band wire
antennas, I've thought of minimalizing and chucking the lot and going with
a single well-designed OCFD wire antenna. One of these days . . .
73, Barry N1EU
On Wed, Sep 23, 2015 at 10:00 AM, Barry LaZar <k3ndm at comcast.net> wrote:
> I stand corrected. That is a great piece of research. All of what I
> knew of the Windom was from material from the ARRL and early material from
> CQ which credited Windom with the original work. However, we, the ham
> community, still call an off center fed dipole a Windom and accept it as a
> multiband affair.
> Until recently, there had been no consideration for impedance; radios
> up until ~the early 1950's had wide enough impedance matching abilities to
> not make this too big an issue. However, with the advent of coax and it's
> acceptance, this became a problem. Hence, the look back for ways to make a
> multiband antenna, an impedance bounded antenna. The "Windom" was one that
> could fit the bill as you could find a feed point that allowed matching to
> a coax feed. And yes, I am aware of some interesting schemes other than
> coax. Unfortunately, the affects of high SWR on a voltage type balun
> transformer weren't as widely known as they are today. That led to RF in
> many a shack. we have a better understanding of the phenomenology today so
> it isn't as big an issue.
> There have been many who have played with single wire antennas. The
> group/ham club that created the variant called the Carolina Windom is one.
> They actually deliberately caused a portion of the feed line to radiate.
> It's my main antenna and it does a pretty good job. Was it the only way to
> go? Probably not when you consider some of the other approaches out there.
> I argue that antennas are for hams what anchors are for sailors, a basis
> for deep meaningful disagreement. However, I do stand by my position that a
> 1/2 wave on the lowest operating frequency that you can feed successfully
> makes a pretty good general purpose antenna.
> ------ Original Message ------
> From: "Rick - DJ0IP / NJ0IP" <Rick at dj0ip.de>
> To: "'Barry LaZar'" <k3ndm at comcast.net>; "'Discussion of Ten-Tec
> Equipment'" <tentec at contesting.com>
> Sent: 9/23/2015 3:54:48 AM
> Subject: RE: [TenTec] [Ten Tec] OCF Antennas - Which commercial antenna is
> Good Morning Gang,
>> Indeed there is some historical perspective missing:
>> ...1. Loren Windom did not invent the Windom
>> ...2. The Windom was NOT designed to be a multi-band antenna
>> ...3. It definitely NEVER was fed at the 1/3 point
>> Everything Barry write below that I agree with.
>> Guys, there is no need to guess at this stuff.
>> MOST of it was written up in QST and ALL of it is online in the ARRL
>> archives to read.
>> I will list some of them at the bottom of this email.
>> ...1. The Windom, named after Loren Windom, was the result of a two part
>> studies/paper as a project in order to obtain a college degree (from Ohio
>> State University).
>> Part 1: was led by John Byrne (W)8DKZ, together with Ed Brooke (W)8DEM -
>> Part 2: was led by John Byrne, together with A. Crawford (was also a ham
>> I can't find/remember his call sign) - 1927/28
>> There was actually a Part 3: where Byrne turned the project over to John
>> Ryder W8DQZ. I could not find any information on what Ryder did.
>> The (assistant) Professor overseeing the project was William Everitt.
>> Loren Windom (W)8GZ was best friends with John Byrne and together they
>> one of the hottest ham radio stations at the time. It was on the air as
>> (later W8GZ) running 250w, which at the time was considered as a
>> Kilowatt" is today.
>> The projects goal was to find a better way to feed a Herz antenna.
>> You see, these guys were having similar problems we "enjoy": RF in the
>> Shack and feedline radiation.
>> Loren Windom and others felt they could find a sweet spot to [single wire]
>> feed the Herz where the feedline would not radiate. Windom failed to find
>> this point, but later Byrne and Co. found it.
>> Windom himself had been working on this a few years earlier and gained
>> from his own research work. You can read details of his research and
>> (flawed) results in a July 1926 QST article written by Robert Kruse, the
>> Technical Editor at the time. The article, entitled "Feeding Antennas"
>> begins on page 8 and Windom's work is described on page 11.
>> The professional paper on this research work was published in the IRE in
>> October of 1929, one month after Windom's QST article. The IRE article
>> been submitted first but took longer to get published. That's why many
>> people think Windom was the creator, when indeed he begins his paper by
>> clearly stating that it is not his work but rather the work of John and
>> others (listing them all).
>> Everitt's name also appeared on the IRE paper, listed first as it was
>> tradition to list the Professor's name on papers written by students. As
>> result, many people credit Everitt as being the true inventor of the
>> To be fair, IMO they all as a team are the joint inventors. Windom (a law
>> student and later lawyer) and Everitt were out in the field assisting
>> lunch breaks and evenings.
>> ...2. "RADIATION-FREE FEEDLINE OF A HERZ ANTENNA" (on its fundamental
>> frequency) was the goal of the Windom. There was no attempt to find a
>> harmonic antenna.
>> A radiation-free feed point was indeed found, but not by Windom. The
>> antenna was named after Lorem by a twist of luck.
>> A Windom (antenna) was a very special, very narrow-banded antenna.
>> However without Internet and few people having telephones in the 1920s,
>> information was spread by other means - mostly on the air in the ham
>> community. The original concept was not understood and that part of the
>> story was dropped.
>> People begin building this antenna (as described in an article Loren wrote
>> on page 19 of the September 1929 QST) and then began "improving" it.
>> They tried it on harmonic bands. It worked. Worked? Yes they made QSOs
>> it wasn't working as a Windom, it was working as something in between a
>> and "Inv.-L" antenna, as described in detail by John Nagle, K4KJ in the
>> issue of HR. I won't elaborate here. You can read the article if you want
>> to know more.
>> I personally built this harmonic version in 1963, right after moving from
>> Germany to Oklahoma. I was the new kid on the block and didn't know
>> anybody. Within one week of erecting my "Windom", I had met all of my
>> neighbors! (hi)
>> Yes, I too called it a Windom, even though it was not the original as
>> and Co. had defined.
>> ...3. As I stated in an earlier email, a feedpoint was found but not at
>> 1/3 mark. It was found to be in a formula with a coefficient with respect
>> to the diameter of the wire. The coefficient was defined for two wire
>> as the feed point position "D", in terms of feet from one end of the
>> It was defined as (Length of Aerial in ft.) x (Coefficient) / 180.
>> For #14 wire, the coefficient was defined as "25".
>> For #24 wire, the coefficient was defined as "30".
>> The wire itself was a one half wavelength Hertz.
>> As you see, there was no mention of "1/3" anywhere in the Windom paper or
>> the professional IRE paper.
>> On a side note, Harmonic Resonance was found to be 2.07 x Fundamental.
>> So a Herz cut for 3.500 MHz would be resonant on 7.245 MHz.
>> Higher harmonics were resonant outside of the band.
>> Using the antenna that far off resonance resulted in strong feedline
>> This was exactly the thing the Windom concept was trying to eliminate.
>> So any contention that a Windom antenna is a harmonic antenna is false.
>> However, the beast that hundreds of hams were using as a harmonic antenna
>> the 1930s was being called a Windom, when indeed, according to K4KJ (see
>> article) was in reality just a bent longwire.
>> As we all know, a longwire antenna can be used on harmonic bands. It also
>> needs radials or a counterpoise; the coax-fed OCFD does not. These are
>> entirely different antennas.
>> Over the years the saga has been modified and few people have any idea
>> these pioneers actually did with the minimalistic means they had to work
>> with. I found it fascinating researching this topic and for those of you
>> who are also interested, here is a list of interesting reading:
>> ..> "The Hertz Antenna at 20 and 40 Meters" by Howard Williams, (W)9BXQ -
>> QST, July, 1925 p.24.
>> ..> "Feeding the Antenna" by Robert Kruse - QST, July, 1926 p.8.
>> ..> (Original Windom Paper) "Notes on Ethereal Adornments", by Loren
>> (W)8GZ - QST, September, 1929 p.19
>> ..> "The Windom", by Drayton Cooper, W4WXY - 73 Magazine, July, 1962 p.34
>> ..> "Further on; The Windom" by W3AFM - 73 Magazine, August, 1963 p.76
>> NOTE: At the bottom of that document you will find a list of 13 related
>> articles from various sources, dating back to the late 20's and up to
>> ..> "Windom Antennas" by John Nagle, K4KJ - ham radio magazine, May, 1978
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Barry
>> Sent: Wednesday, September 23, 2015 1:04 AM
>> To: tentec at contesting.com; Rick at DJ0IP.de
>> Subject: Re: [TenTec] [Ten Tec] OCF Antennas - Which commercial antenna is
>> I think there is some historical perspective that is missing in some our
>> discussions. First open wire was used in the early days of radio as there
>> wasn't much else around. You could run a wire from your antenna directly
>> your transmitter's output, but there were really few other ways to go.
>> came into being somewhere around 1940, and this can be disputed, for the
>> purpose of running a transmission line through a ship's steel bulked. The
>> 50 Ohm number came about because that is what resulted from the material
>> hand, or you can supply another story.
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