By G. E. "Buck" Rogers Sr;  K4ABT

In September of 1949, I was tired of climbing poles and trees to move, remove, add, or change my single-band HF antenna's.  In those younger years of my HAM radio career, I had used single band dipoles and doublets for almost every HF Amateur band.  I had tried long-wires, doublets, dipoles, and Zepps, but again, operation was restricted to single band operation, maybe two bands at most.

I had heard of the "Windom" and read a few articles about the Windom, but most of my thoughts were ... ho-hum.. just another dipole fed a bit off-center.  Then one evening at a meeting of the GARC in the old "Sea Scouts" club house near the Coosa River in Gadsden, Alabama; I heard some of my "elmers" Gale Caudle (then W4CFB), Jack Kennamer W4YPC, Bob Bynum W4USM, Vic W4CWF, Ed Elkins W4CDI, Homer Dupree W4OZK... and others discussing the Windom all-band HF antenna.  It was when Jack mentioned using one (Windom), on most all HF bands "without an antenna tuner"  that my ears went directional!

That last phrase caught my undivided attention.  "most all HF bands, without an antenna tuner....etc" 
What !  A multi-band HF antenna without a tuner?   Surely I had been blessed. 

To think that I could put up a Windom, and no longer have to climb the poles and trees to hang another (single band) HF antenna was great news to me.  To be able to use it without an antenna tuner was icing-on-the-cake.  For a kid without extra funds, an antenna tuner was a luxury that I could not afford.  Even my transmitter was a single 807 rig I homebrewed on an old Atwater-Kent radio chassis, my grand-father had given me.

In those days, a BALUN was unheard of.  My Elmer's described, a means of connecting the coax to the off-center fed antenna using a nine (9) turn coil of the coax feed-line at the feed point.  This coil of feedline coax formed a "de-coupling" loop.  The de-coupling loop provided a crude means of matching the feed coax to the antenna, and at the same time, it would reduce the "re-radiation" (RF currents) along the outside (shield) of the feeder coax.

Today we have toroid cores and BALUN devices that provide a more efficient means of coupling RF energy to the antenna (reducing the VSWR, "standing-waves"), while performing better impedance matching.  In the drawing shown above, I've drawn the exact dimensions of the Windom I built in 1949.  The only differences in my Windom of 1949 and today are:

1) the material the insulators are made of, and
2) I've substituted a 4 to 1 BALUN for the 9 turn, 8 inch diameter, decoupling loop.

 

AN UPDATE:

Since writing this article a few decades ago for a major HAM radio magazine, I've received tons of mail (and eMail) asking for more information, especially with regards to a 160 meter version;  Here then is "the rest of the story."

 

First of all, we'll address the formula, and how to determine the length(s) of each section,  using the same old formula that I used in 1949.

 

Long side....  = 468, divided by the frequency, then multiply by  .66    (= Feet)  

 

Short side.... = 468, divided by the frequency, then multiply by  .33    (= Feet)
 

THUS; for 160 thru 10 Mtrs......... 

 

Long  Section;         468/1.8 MHz = 260  x  .66 =       171 feet.

Short Section;         468/1.8 MHz = 260  x  .33 =        86  feet.

 

or for 80 thru 10 meters:

Long  Section;         468/3.8 MHz = 123 x  .66 =       81.5 feet.

Short Section;         468/3.8 MHz = 123  x  .33 =      40.5  feet.

 

Now it's time for me to P O the wire and cable vendors, and the proponents of Windoms with too many feed-line transitions.   Twin Lead, Ladder-line, Window Line..... etc..  is an over-kill.. The trade-off is not...; I repeat;  NOT... worth the pain and upkeep to replace it each year or two. 

 

And trust me... It is NOT a problem of the ladder-line insulation quality or properties that I'm speaking of.   I speak from experience;  Wind will destroy ladder/twin-lead line.  Even the robust type will succumb to the wind element in a short period of time.  

 

IF... (and I pray that you don't), ... but IF; you decide to use ladder line, make one turn (twist) to each 20 to 24 inches of line to decrease the wind resistance presented by the "flat" line......... even if it is "window-slotted" type ladder-line.  By adding the one twist per 20 inches,  it may last as long as three or four years.

 

COAX does NOT present a high degree of wind resistance, and it'll last much longer.

 

Having been there, done that, and heard similar horror stories from others;  another question  arises regarding parallel line currents that come with the use of so-called balanced (twin-lead) feed-lines.  To add injury to the ladder-line proposition, the balanced line may also assume the properties of a single wire feeder (yuk).  

 

Some purveyors of the Windom that use ladder-line transitions, must use two impedance matchers (or BALUNS) with their (knock-off) Windom.  One is to transition the coax outside the HAM shack (heaven forbid, we use ladder-line inside the shack... RF "feedback" in everything), to the ladder line, then another at the Windom (antenna) feed-point to choke off parallel current from the ladder-line.

 

Since the feed point of this antenna has been found to be near 220 to 260 ohms, the use of a 4:1 BALUN to join our coax to the antenna, emerges as a compromising solution. 

 

Let's not lose sight of the most important advantage of using this antenna; and that is: It provides us with a powerful, multi-band antenna, and a minimum of feedline components.

We're having fun, on PSK31     73 de BucK4ABT