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 hobby, 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" Gilbert Watson (SK) W4PAC, Gale Caudle (then W4CFB), Jack Kennamer (SK) W4YPC, Bob Bynum W4USM, Austin (Vic) Vickery, Walter Damkohler (SK) W4EBO, W4CWF, Ed Elkins (SK) W4CDI, Homer Dupree (SK) W4OZK, Jim Runyan, Homer O'Dell, Robert Martin, .... and others discussing the Windom all-band HF antenna. It was when Jack (W4YPC), mentioned using one (Windom) antenna, on the all HF bands that my ears went directional!
That last phrase caught my undivided attention. "most all HF bands, ....etc"
What ! A multi-band HF antenna ? 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 .64 (= Feet)
Short side.... = 468, divided by the frequency, then multiply by .36 (= Feet)
THUS; for 160 thru 10 Mtrs.........
Long Section; 468/1.8 MHz = 260 x .64 = 166.4 feet.
Short Section; 468/1.8 MHz = 260 x .36 = 93.6 feet.
For 75 thru 10 meters do similar math to arrive at/near the dimensions shown in the drawing below, but for best results, use the formula.
The Windom can be installed as an inverted VEE, or as a sloper, but in no case, should the angle be less than 90 degrees against itself. To use an angle that folds against the pattern of the opposite end of the Windom, would change the impedance of the feed-point, change the multi-band features, and most important, destroy the radiation characteristics of the antenna.
In other words, install the Windom as you would any other dipole, while using a common sense approach. The fact that we are feeding
this Windom using coax, and a single balun, gives us the ability to construct it as an inverted VEE or at a "real estate saving (angle)" without destroying the features and performance of the Windom.
This is not true with those antennas fed with ladder-lines and those that have several impedance transitions built into the feeders of the "basic" Windom....... There's more to come, so read on!
BUX DYPOLE; picture at left is a relative diagram of our dipole antenna. The dipole can be erected as an Inverted Vee or as the classic standard, dipole.
The dipole you receive in our Dipole antenna package is made of strong ThermaFAX™ insulated, silver bearing, number 16 (stranded) wire. BALUN and insulators are included and installed.
The antenna is completely assembled, ready to connect your coax, and erect. You'll be air-borne in just a few minutes. It can be used with 50-75 ohm coax. The use of a balun is recommended! In the BUX Dypole package, we include a 1:1 balun as part of this antenna package. The BUX Dipole package is cut for 3.9 MHz, (75 meter, or 120 feet), however, we supply a cutting chart that allows you to build it for 40 or 20 meters.BUX DYPOLE $39.90
ANTENNA INSULATORS
Weatherproof, (TENYTE) insulators. Perfect for your DIPOLE or Windom antenna.
ANTINSL3
For the apartment dweller, you can now hang the 20 meter doublet
in the attic. I've QSO'd with stations all over the world with the
33 ft dipole in my garage attic. One insulator at the center, and one each end.
It's great for other HF WINDOM and single-band dipole antennas. Dielectric strength is comparable to the old ceramic insulators, without susceptibility to cracking or breakage under impact or extreme temperature changes.
Package of 3, $2.99
Package of 10, TeNyte Insulators $8.99, ANTINSLX10
Now it's time for me to P O the wire and cable vendors, and the proponents of Windom's 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 every 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 time.
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 longer than three 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.
Now for the "perfectionists" among us, if you want to smooth out the hills and valleys on some of the bands, add your antenna tuner to the system, and the Windom becomes very flat across the bands. When I say "flat," we are talking about reducing the VSWR to a minimum, to produce a good forward power, transfer of RF energy to the Windom.
We're having fun already... with the Real WINDOM antenna
The "Windom Antenna" was described by Loren G. Windom in QST magazine, September 1929. Pages 19 through 22. It is named after its inventor/designer.
Loren Windom, W8GZ, was first to reveal the antenna to the radio amateur community by describing the antenna in the September 1929 issue of QST. It was by Windom's name that the antenna became known. The Windom antenna is an off-center fed dipole with an unbalanced coax feedline.
In 1937, the Windom was first described as a compromise multiband antenna. The antenna can be employed on 80, 40, 20 and 10m with considerable, though acceptable levels of VSWR. What became perhaps the most popular multiband Windom design of all, was the German-made Fritzel FD4 antenna, described by the late Dr. Fritz Spillner1, DJ2KY, in 1971. It had the same dimensions as the multiband Windom antenna, but fitted with a 200Ω (4:1) balun in its feedpoint and fed with coax.
Today, many radio amateurs are using multiband Windom antennas with more than satisfactory results. It would not be without reason that Windom antennas are being employed during IARU HF World Championships! and most of all, by "high-stake-contests." Perhaps many young hams ignore the multiband Windom antenna because of its sheer simplicity and may be thinking it is too good to be true. The complexity of feeding other dipoles and doublets, the losses in dipoles with traps and the esoteric marketing of some other antennas seem to appeal to them more.
CLICK HERE: and read more about the evolution of the WINDOM, to ZEPP, to VHF J-POLE.
BUX BALUNs should be installed at the antenna feed point, or where the coax or feed-line attaches to the above ground antenna. BUX BALUNs are used to connect balanced antennas to unbalanced transmission lines, such as coax cable. Their primary purpose is to prevent antenna (RF) currents from flowing down the outside of the cable. Another function of the BUX BALUN41 is to match the impedance of an unbalanced coax to the balanced feed point of a balanced input antenna(s). BUX BALUNS may also be used as “line isolators” anywhere along the cable to prevent the destructive influence of induced RF currents (VSWR).
BUX 1:1 BALUNs are current BALUNs. They consist of several large, number 73, ferrite type 44 cores. BUX BALUN11 operate from 3.5 to 72 MHz and allow use of RF power to the rated capacity of the BALUN.
BUX 4:1 BALUNs are voltage BALUNs. They consist of a large, number 41, ferrite dough-nut bobbin. BUX BALUN41 operate from 3.5 to 55 MHz and allow use of RF power to the rated capacity of the BALUN.
At BUX COMM, *We don't cut corners!
The components used in the manufacture of our BALUNs are from top quality components, beginning with the Silver Plate SO239 connectors and center insulator is made of teflon™(E.I Dupont). The wire we use to wind the ferrite donut is heavy-duty, silver flashed wire, with teflon™ insulation that will handle RF voltages above 5000 volts, and temperatures above 2000 degrees. The binding posts are heavy-duty, tempered brass, with end holes and side-thru holes to accommodate either type loop-thru connection. A double-shoulder brass capture nut is used to add a secure bite and improve antenna wire electrical connections. With our BUX UN UN (ONION), the coax is Belden™ and the PL259 connectors are Amphenol™.
4:1 Balun, BUXBALUN 41 $19.95
o 50 ohm, SO-239 unbalanced input
o Balanced output
o 1.6 to 50 MHz
o Toroid (Voltage) design
o Heavy Duty, Lightweight construction
o Sealed against moisture
____________________________________________________
1:1 Balun, BUXBALUN 11 $19.95
o 50 ohm, SO-239 unbalanced input
o Balanced output
o 1.6 to 50 MHz
o Toroid (Current) design
o Heavy Duty, Lightweight construction
o Sealed against moisture
____________________________________________________
BUX UN UN De-Coupling transformer, similar to above, but has SO-239 (female)
input connector and output connector is 1 ft Mini 8 cable with PL-259 (male).
BUX ONION $19.95
4:1, 1.5kw Balun, BUX BALUN 41HD $27.95
Toroid design, wound with teflon covered, silver plated wire.* Heavy-Duty, construction.1:1, 1.5kw Balun, BUX BALUN 11HD $27.95
Toroid design, wound with teflon covered, silver plated wire.* Heavy-Duty, construction.1:1, 1 kw VHF Balun, BUX BALUN 11V $24.95
Hi-Q, toroid design, wound with teflon covered, silver wire. For VHF beams and J-Pole matching applications, and construction.
Includes 6 ft, high-quality PL-259 to PL-259 Mini-8 cable/jumper. Connectors are Amphenol™ with Belden cable.
BUX ONION "Decoupling Transformer"
BUX UN UN De-Coupling transformer, has SO-239 (female)input connector and output connector is 1 ft Mini 8 cable with PL-259 (male).
BUX ONION is and UNbalanced to UNbalance (UN-UN) decoupling transformer designed to be used specifically with the DBLSPCL antenna. High RF currents traveling along the coax feed-line shield can cause high VSWR. This decoupling transformer prevents RF currents from traveling down the outer shield of the coax. The input connector is an SO239 (female) and the output connector is a PL259 (male), which mates the connector of the "DBLSPCL" RV/Apartment dweller antenna shown above.BUX ONION $19.95
Important Notice; WHY USE A 4:1 BALUN
Krusty Olde Kurt is now going to repeat himself. Why? Because the same question keeps coming up over and over. And he wants everyone to get it right.
"I'm feeding my dipole with 600-ohm line. At the station end I need a balun to convert to 50-ohm coax. I need a 12:1 balun, right?" Wrong! A 4:1 balun would be better.
Why is that? If your dipole is up, let's say, 35 feet then on 80 meters it will probably have a resistance at resonance of about 40 ohms. The actual resistance depends on the height above ground in wavelengths.
If the dipole is 40 Ohms then what do you see at the transmitter end of your 600 ohm line? If the line is a half-wave long (120 ft on 80 Meters) you'll see 40 ohms. Remember, a half-wave line repeats what it sees at the other end. But if it is a quarter-wave long you'll see 8500 Ohms! At other line lengths you'll see impedances somewhere between these two extremes.
So you are not going to see 600 ohms at the end of your 600-ohm line. That only happens if you have a 600-ohm antenna hooked onto it. With such a variation in impedance at the transmitter end of the line there is no one balun transformer that will match it. Most of the time the impedance will be above the 50 Ohms of your coax so a high impedance balun would be desirable. Unfortunately high impedance baluns don't work well when not matched.
Experience has shown that 4:1 baluns work best in this service. They are more rugged and will take bad mismatches especially if they are wound on an iron powder core. So stop searching for that 12:1 balun. Use a 4:l BALUN and your system will work great.
You can read Kurt N. Sterba “AERIALS” column in World Radio Magazine.
BUX MOBALUN
When you hear those strong HF mobile signals, here's one reason they stand out from the rest.
By installing the BUX MoBalun near the input to your antenna, you deliver more RF energy to the antenna. At the same time, the BUX MoBalun prevents RF from traveling back along the shield (high SWR) of your coax. High power rating, Low-permeability toroid, with Internal composition fiber-glass to prevent vibration during mobile operation. For input and output connectors, we use only the best Silver plated, Teflon insulated, SO239 connectors. 700 watts PEP. Our MoBALUN is also ideal for marine antenna installations.
$19.95 MOBALUN
ANTENNA INSULATORS
Weatherproof, (TENYTE) insulators. Perfect for your DIPOLE or Windom antenna.
For the apartment dweller, you can now hang the 20 meter doublet
in the attic. I've QSO'd with stations all over the world with the
33 ft dipole in my garage attic. One insulator at the center, and one each end.
It's great for other HF WINDOM and single-band dipole antennas. Dielectric strength is comparable to the old ceramic insulators, without susceptibility to cracking or breakage under impact or extreme temperature changes.
Package of 3, $2.99 ANTINSL3
BUX DYPOLE; picture at left is a relative diagram of our dipole antenna. The dipole can be erected as an Inverted Vee or as the classic standard, dipole.
The dipole you receive in our Dipole antenna package is made of strong Teflon™ coated, silver bearing, number 16 wire. BALUN and insulators are installed.
The antenna is completely assembled, ready to connect your coax, and erect. You'll be air-borne in just a few minutes. It can be used with 50-75 ohm coax. The use of a balun is recommended! In the BUX Dypole package, we include a 1:1 balun as part of this antenna package. The BUX Dipole package is cut for 3.9 MHz, (120 feet), however, we supply a cutting chart that allows you to build it for 40 or 20 meters.BUX DYPOLE $39.90
UHF DOUBLE FEMALE BULKHEAD (feed-thru) CONNECTORS
For bulkhead and through-the-wall UHF connector feed-thru connections, with keeper nuts.:Order 7518-2 (Two inches) $ 2.95 ea.
Order 7518-4 (Four inches) $ 3.95 ea.
Order 7518-6 (Six inches) $ 4.95 ea.
Order 7518-8 (Eight inches) $ 8.95 ea.
Order 7518-10 (Ten inches) $ 10.95ea.
Order 7518-12 (Twelve inches) $12.95ea.
Heavy Duty (1") Nuts for the above bulkhead connectors.
2/.99 cents HDM1-NUT
50 Ohm impedance, 3 ft, 6 ft, 9 ft, 12 ft, & 18 feet.
These jumpers are made from high quality, low-loss, coax cable with PL-259 connectors installed at each end.
Three ft. (3') ORDER No. 8X3-PLPL $3.95
Six ft. (6') ORDER No. 8X6-PLPL $4.95
Nine ft. (9') ORDER No. 8X9-PLPL $5.95
Twelve ft. (12') ORDER No. 8X12-PLPL $7.95
Eighteen ft. (18')ORDER No. 8X18-PLPL $8.95
Reinforced, Double Bracket used with our "DBLSPCL" antennas shown elsewhere on this page.
Mount two mobile whips in a horizontal plane to form a compact apartment dweller Dipole, or RV antenna. Comes with two sets of mounting hardware (bolts), those shown here and another
set of longer bolts for larger masts. Double Antenna Bracket as shown at left.
$16.95 DBLBRKT
After a few years, the hardened, nylon shoulder washers become weather-brittle and break. Keep a few spares in the Ham Shack:
4 for 99˘ SM1SW
Mobile tuneable-tip antennas.BHF75M 75 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF40M 40 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF20M 20 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF17M 17 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF15M 15 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF10M 10 METER 3/8" X 24 THREAD 8 feet long $16.95
BHF6M 6 METER 3/8" X 24 THREAD 5 feet long $16.95
Spare 48" Tips for above tuneable-tip antennas. TIP48, $2.95
Here's the perfect solution for your RV and portable HF antenna applications. Use our dipole, mast-mounted bracket for 'fixed-station', field-day operating, apartment dwellers, and the RV travelers. With two of the mobile HF antennas shown at left, you can have the best of both worlds.
By combining a pair (two) of the single band HF Mobile (loaded) tuneable-tip antennas, and (VHF) whips at left, you can have an ideal, single element, horizontal dipole (beam). This type antenna opens the world of HF and VHF communications for the apartment dweller, RV HAM, field-day operating, and a variety of other uses and applications. Shown mounted on 1 & 1/4" mast. Antenna(s)
Not Included.
$16.95 each
DBLBRKT
tuneable-tip antennas allow adjusting for minimum VSWR.
CLICK HERE to read more about our HF DIPOLE SPECIAL!apartment dweller, RV HAM, field-day operating, and a variety of other uses and applications. The packages described below include two antenna, the Double Antenna-Bracket (DBLBRKT), and mounting hardware By combining a pair (two) of the single band HF Mobile (loaded) tuneable-tip antennas above, you can have an ideal, single element, horizontal dipole (beam). This type antenna opens the world of HF communications for the
$ 39.97 DBLSPCL (without BALUN) With BALUN, see "DBLCOMBO", below.
75 Meters→
17 Meters→
6 Meters → By combining a pair (two) of the single band HF Mobile (loaded) tuneable-tip antennas above, you can have an ideal, single element, horizontal dipole (beam). This type antenna opens the world of HF communications for the apartment dweller, RV HAM, field-day operating, and a variety of other uses and applications. The package described below includes two antenna, the Double-Bracket (DBLBRKT), mounting hardware, and BUX BALUN (UNUN). $AVE $$$$$, ADD the BUX UNUN , shown below, BOTH, DPLSPCL & BUXUNUN, for only $ 54.97, ORDER, DBLCOMBO
75 Meters→
17 Meters→
6 Meters → We accept:
FAX 434 525 7818 or Mail order form, Click Here!
Web Page Design and HTML By G. E. 'Buck' Rogers Sr K4ABT d/b/a BUX CommCo™® © Copyright © 1996-2005 All Rights Reserved
BUX CommCo™®
115 LUENBURG DRIVE
EVINGTON, VIRGINIA 24550FAX 434 525 7818
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