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The HAM Radio Operator's Antenna Handbook
by Buck Rogers ( K4ABT, more than 68 years) HAM = Helping All Mankind

For TNC to Radio Interface Cable Diagrams, CLICK HERE !     For PSK31 & SSTV Interface Diagrams, CLICK HERE !

A Four Element Yagi Antenna Calculator

Enter Frequency- Click Calculate- 
Reflector Length = Ainches
Driven Length     = Binches
Director Length   = Cinches
Director Length   = D inches
Spacing               = E inches
4 element Beam ledgend

For the VHF/UHF frequencies, a 4:1 impedance ratio coaxial balun is normally used. Two sections of identical coaxial cable are needed.
One section (A) has a convenient length to reach between the antenna and the transmitter.  Its characteristic impedance is Z.
The other section (B) is a half-wavelength long at the center of the frequency of interest.
The "physical" length is found from: 5904/F = L.  The complete formula is:

        L = 5904 * V/ F  in MHz

where;
L is the cable length, in inches F is the operating frequency, in megahertz
V is the velocity factor of the coaxial cable. 
The result is found by multiplying L by V.
To find the "Electrical" length, divide this result by F.
The velocity factors of common coaxial cables are shown in the following table.

Coaxial cable velocity factors
Regular polyethylene 0.66
Polyethylene foam 0.80
Teflon 0.72

 Both radio signals and light travel almost 300,000,000 meters (186,363 miles) per second.
When designing a matching or phasing BALUN for a VHF or UHF Yagi, the quarter wave transformer is where these calculations will come to life.   Most coax cables we use in HAM radio have varying velocity factors (VF).  That is; RF signals travel at different speeds through these coaxial cables, depending on the cable type we use.   For example, the coax cable you are using has a velocity factor of .80%.  This indicates that the electrical length is actually 80 percent of of its "free space length".  When making a VHF or UHF BALUN or phasing transformer we must be sure we have included the velocity factor in our computations.

To calculate the actual (electrical) length of the phasing line or BALUN you should first determine the line length needed at the frequency of operation by multiplying the "real world" length of the coax by the velocity factor of the coax as determined by the manufacturer.

If you wish to do the calculations for a yagi dipole feed using the long method, then the following formula will suffice: 
        234/f  = L * VF,          
    Where: 
        234 is the constant used to compute a quarter wavelength when divided by the frequency (f) in mHz.
        L is the Length in "feet" multiplied by the velocity factor (VF) percent, expressed as a decimal.

Example:     We'll determine the electrical length of a BALUN for a 2 meter beam driven element with a center frequency of 146 MHz.  Our
                    Yagi dipole has a 35 ohm impedance feed point.  I order to match that feed point we'll need two (2) lengths of 75 ohm coax. 
                    In our BALUN the two lengths will appear as parallel making the output impedance near 37 ohms.  The input is near 52 ohms.
                    We'll select RG-59* for it better VF quality, and 75 ohm impedance.  To complete the calculation, we need to have the velocity
                    factor for the coax we plan to use for our BALUN.  The following chart contains the velocity factors (VF) supplied by the cable
                    makers:  From the chart below, we locate the RG59* and in the column under "VF" we find 0.79.  We now have the ingredients
                    to complete our equation.

    Thus:       234/146 = 1.60 * 12 (multiply by 12 to find inches) times .79 = 15.5 inches (approx)
                  
4to1 BALUN for VHF folded dipole

Type FP=foam
PE=Poly
Eythelene
Shield Diam. VF Atten/
100ft
50 Ohm Coaxial Cable
RG-8 FP 97% 0.405 0.78 0.5db
RG-8* FP *96% 0.480 0.78 0.5db
RG-8A PE 97% 0.405 0.66 0.5db
RG-8X FP *96% 0.325 0.82 0.5db
RG-58 PE 95% 0.193 0.66 1.2
RG-58A PE 96% 0.195 0.66 1.4db
RG-58A* PE *96% 0.240 0.66 1.5db
RG-58C PE 96% 0.195 0.66 1.4db
RG-174 PE 88% 0.101 0.66 3.3db
9913 FP 100% 0.405 0.84 0.4db
75 Ohm Coaxial Cable
RG-11 FP 95% 0.405 0.78 0.4db
RG-11A PE 97% 0.405 0.66 0.7db
RG-59 PE 95% 0.146 0.66 1.1db
RG-59* FP *96% 0.315 0.79 1.0db
RG-59B PE 95% 0.242 0.66 1.1db

 

 

 

 

 

 

 

 

 

 

 

 

 

 

* = Double shielded Coax
  VF = Velocity factor of coax

OR... if you prefer, use the calculator below to solve the length much easier.

Switch to:
( Speed of RF in free-space, Divided by   Frequency  )   Times   Velocity Factor (%)
(Line Length Required) Enter .25 for one-quarter, or .50 for one-half
*Note: Use .25 when matching a dipole driven element, or .50 when  matching a "folded dipole.")


The line length "B" should be: (to convert feet to inches, multiply B {ft} by 12) Select "Feet" or "Meters" above.


More, Antenna Handbook Contents

 A Method for hanging a BALUN without adding stress to BALUN binding posts.
 
Of all HF antennas, the multi-band WINDOM is my favorite.
 
An improved 6 Meter "High-Performance" Base-Station Dipole.
 
HF Antenna Cutting Chart
 
HF 80/75, 40, 20, & 10 meters. Trap Antenna with double-core High Q traps for improved performance.
VHF & UHF Antenna Cutting Chart
 
Determine correct spacing between antennas to archive proper isolation.
 
A two meter dipole
 
 A TV twin-lead two meter J-Pole; It's very portable and EZ to build !
 
Detailed drawing of a two meter "J" Pole antenna.
 
Detailed drawing of a six meter "J" Pole antenna.
 
Design your own "J" Pole antenna.
 
Design your own QUAD antenna.
 
A 4 element, six meter QUAD design using Design-A-Quad.
 

Antennas and Antenna RF Meters
                                        AND MUCH MORE, Scroll On ..!!

BUT FIRST.... let's review some antenna "basics" in pictorial form.





When using a Dipole made similar to the above antenna, it is highly recommended
that a 1:1 BALUN be used at the antenna feed point (center insulator).









Antennas & Accessories



CLICK ON the small graphic to view full size.

Half-Wave HF Antenna Cutting Chart.

 



CLICK ON the small graphic to view full size.

VHF/UHF Cutting Chart
 



CLICK ON the small graphic to view full size.

Antenna Isolation / Spacing Charts


Trap Antennas


80/75, 40, 20, & 10 Meters, Total length is 84 feet. Two, High-Q, double-core traps for optimum performance. 
This BUXCOMM antenna has been discontinued. 


Loop Antennas

INSTALATION and SETUP:  The "BUXLOOP” antenna is completely assembled, with all wire, "float" insulators, "center fixed" insulators, BALUN attached, ready to hang and attach your coax. 

*  LOOP Antennas have less electrostatic noise in your receiver.
*  LOOP Antennas provide additional gain over conventional wire type antennas
LOOP Antennas perform especially well over poor conducting earth like sand and lossy soils.

Many HAMs will tell you about a great antenna that is one of the better performing wire antenna's and one of the best kept secrets in HAM Radio.  It is called, the Full Wave LOOP Antenna There are several factors to consider when choosing your wire gauge and type. BUX COMM uses number 14 AWG, silver-flashed-copper, made up of 41 strands, covered with Sky-Blue PVC. The (41) multi-strands provide an added (tensile) strength.   Because the wire size, most often referenced by HAM radio articles, is: High-Tensile Strength 14 AWG, we have chosen it as the preferred size for our Full Wave, 80 thru 10 meters, LOOP antenna wire size.    The BUXCOMM LOOP Antenna  requires 70'by 70' of real-estate.

 

We calculate the length of the Full Wave Loop Antenna for the lowest band to be used.   This formula is as accurate as you find for any "loop antenna" on the HF bands.  In the construction of our BUX COMM antennas, we use a special, high grade, and High tensile strength wire, with 41 strands of silver flashed, copper covered with an esthetically blended sky-blue IR resistant PVC covering.  Our sky-blue covering will not affect the RF transmission in any way. 

 

BUXCOMM HF loop antenna are installed and supported in one of two ways, "fixed and floating."  We use the “floating” method of support for three (3) corners.  The three far corner insulators are already on the loop when you receive the assembled antenna. One corner insulator is moved to the right corner, another is slid along the loop to the far corner (and diagonal away from the feed point), another insulator is set to the left corner position, thus "floating" the three (3) corner support insulator(s).  When building the feed point, we employ a different type, "fixed" insulator.  This insulator also supports the 2:1 ratio BALUN.  The main purpose for floating insulators at the three non-fed corners is to enable the wire to move freely through the insulator, thus providing the best support when the horizontal loop is supported by tall poles or swaying trees. 



 A touch of Class,  the J-POLE
By Glynn E. "Buck" Rogers Sr  (65 years as K4ABT)

Between the articles by the late
Lew McCoy W1ICP and myself, the J-POLE, Windom, and ZEPP should be around "forever."
My Hardware J-Poles from 1969

The J-POLE has been around since the early days of HAM Radio, and is a direct descendant of the "ZEPP."  Like the ZEPP, the J-POLE is a spin-off, 
or a modified WINDOM for VHF. One of the first articles I wrote about the J-Pole was in HRC magazine in 1958. Since 1958, I've written several j-pole
articles in other HAM Radio publications.
Here, my references are to the early, 1923 (version) Windom (Article by Loren G. Windom September 1929, QST magazine) .  If you look at the  feed of the 
early Windom that was fed with a single wire, you may soon see the similarity between the Windom, ZEPP, and the J-Pole.
For now, let's look at some of the features of our J-Pole, whether for; 140-150 mHz, or 430-450 mHz 
  • the J-Pole is easy to erect
  • the J-Pole needs no radials
  • the J-Pole has low angle radiation
  • the J-POLE has greater bandwidth.
  • the J-Pole has greater immunity to terrestrial noise
  • the J-Pole is great for local nets or distant repeaters
  • the J-Pole has more gain than most Ground Planes
  • the J-Pole is more durable than most Ground Planes
  • the J-Pole meets most "stealth" antenna restriction agreements
  • the J-Pole has less static-charge noise, and static-charge build-up.

In the mid-fifties, and early sixties, ridged copper was difficult to find, and even if we were fortunate
enough to locate ridged copper, the cost was prohibitive. Most of our VHF (don't even think about UHF)
operating was AM (for the late model HAM, "Amplitude Modulation"), and on two meters, operating was
centered around 144 MHz. We either opt'd for a bamboo spreader cubical quad, or folded "zepp," as we
called it in those days (now-a-days, called a "J-Pole.")
Another variation to this antenna construction was to use electrical thin-wall conduit or "EMT."  EMT actually
means "electrical metallic thin-wall" but somehow early acronyms had a way of getting turned around, or inverted,
. . . or perverted.. hi.
Using metal EMT instead of copper, we learned to use the brazing rods and torch to fabricate our "folded (zepp) Jay."  
In any case, we were able to make the J-Pole happen. For VHF, the J-Pole became the antenna of choice,
just as the Windom took its place as the antenna of choice for the lower (HF) bands. As a matter of interest,
look close at both the J-pole and the Windom, and you might find a close resemblance and maybe even some
relationships in the off-center method used to feed each of them.
I've heard of J-poles stacked, collinearized, and some with weird fitted, 1955 Ford fender-skirts.  Depending on
who's telling the story, they might have more gain than a yagi on a helicopter at 1200 feet, or they won't reach a hand-held
across the backyard. I try to make it a personal point to stay out of these CB University fences. You can put a "mini-skirt"
on it, you can even place a "tutu" on the J-Pole, but the truth is, it remains a Jpole.
As a personal observation throughout my 64 years as a HAM;  Mistakes, Experience, and Knowledge has given
this ole HAM the Wisdom to know the difference. Don't try to build a Windom for two meters, and for
heavens sake, DO NOT attempt building a J-Pole for seventy-five (75) meters.
As they say, "do the math;"
Just the long, vertical section of a 75 meter J-pole would near 200 feet.
TO THE POINT OF OUR SUBJECT:
I've had many requests for a ready-made J-pole design that will enable the Amateur Radio user to print the image 
from a web page and go directly to the construction table and build a J-Pole antenna for their HAM Radio station.
On this page you will find many illustrations I've drawn to help you understand the manner in which a J Pole is built.
Fabrication can sometimes be a problem for the apartment dweller, or the HAM with limited facilities for this kind
of project.
For these reasons, you may wish to purchase the "direct fed Jpole" ready to install.  We offer this BUXCOMM J POL
in two versions;
A VARIATION ON A THEME:


Let's look first at FIGURE 1a;  This is the overview and profile of the  
J-Pole we will be working with. There are two different bands we will be
building the J-Pole antennas for. NO, we will not build a two band antenna
on one mast. I've been there, done that.. and it is an exercise in futility.

For openers, I would like to show you that all J-poles are not created equal.
By that statement; I mean, we will modify our construction techniques a bit
and apply a variation to the theme. Notice in the exploded view
at FIGURE 1b, I've deviated from the usual RF feedtechnique that we normally
use to attach our coaxial cable to the J-pole.

Where we usually attach the shield and center conductor to the tuning stub and the
driven element with aero-seal (hose) clamps, here we've made a slight change
in the design by exchanging the elbow for a tee. Below the short (1/4 wave tuning stub)
section, we (carefully) soldered an SO-239 (Chassi-mount) coax (female) connector.

But notice that we must first attach a piece of number 12 or 14 insulated, copper
wire to the SO-239. The length of this wire depends on the spacing between the stub
and (Fig 1A "D") long section of our antenna.

If the antenna is for six meters, the wire length will need to be about, 10 to 12 inches long.
If our antenna is for two meters, the wire length will be less than 8 inches overall.

I am careful when I (Benz-O-Matic torch) solder the SO-239 to the copper tee, since
I don't want to heat the SO-239 to the point the solder on the wire melts and I have to
begin the process again.
Shown above are our direct feed J-Poles.

USE BUX "VBALUN" withJ-Poles 1 kw VHF Balun,  BUX  VBALUN   $19.95

  > CLICK HERE for on-line CATALOG
Hi-Q, toroid  design, wound with teflon covered, silver wire.  For VHF beams and J-Pole matching applications, and construction. 


BUX J-POLE
FIGURE 1a

BUX J-POLE
Figure 1b

SAVE TIME BY USING THE HANDY J-Pole CALCULATOR BELOW.
 
 
NOTE: Coax center conductor attaches to the "Long section" feed point.

 Shield attaches to the short section feed point.

Hi-Q, toroid  design, wound with teflon covered, silver wire.  For VHF beams and J-Pole matching applications, and construction. 



An adjustable VSWR, 2 meter J-Pole. This same technique can be applied to 6 meter, and 70cm J-poles.


BUX VBALUN should be installed at the antenna feed point, or where the coax or feed-line attaches to the J-Pole 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. 



 



A=Benz-O-Matic propane torch; B=Lead-Free solder; C=Tape measure: D=Tubing cutter; E=Sharpie marking pen; F=Solder Paste; G=1/2 inch copper caps; H=Hardcopy of the above drawing; I=Wet Towel; J=PreCut, ready to assemble parts of the 2 meter J-Pole.
 



 HAM Radio and Commercial 2-way radio antennas



BUX COMM, 142 to 150 MHz; Fiberglass J pol
For low terrestrial noise, use fiberglass elements. For optimum performance and gain,
feed with BUX COMM  "VBALUN."
Courtesy HRC Antenna Newsletter (c)



BUX COMM, 435 to 450 MHz; Fiberglass J pol
For low terrestrial noise, use fiberglass elements. For optimum performance and gain,
feed with BUX COMM  "VBALUN."
Courtesy HRC Antenna Newsletter (c)


Two & Six Meter Beam Construction

Four element, two meter beam, elements can be tubular aluminum, solid aluminum,
or for low terrestrial noise, use fiberglass elements.  This beam may be installed vertical, or horizontal.
For optimum performance and gain, feed with BUX COMM  "VBALUN."
Courtesy HRC Antenna Newsletter (c)



Four element, six meter beam, elements can be tubular aluminum, solid aluminum,
or for less terrestrial noise, use fiberglass elements.  This beam may be installed vertical, or horizontal.

Courtesy HRC Antenna Newsletter (c)


Cubicle Quad Antenna Construction
Design-A-Quad Antenna

Calculate the total wire length for each element of a quad antenna.
REFLECTOR = 1030 / F (MHz)
DRIVEN = 1005 / F (MHz)
DIRECTOR 1 = 975 / F (MHz)
DIRECTOR 2 = 960 / F (MHz)

ELEMENT SPACING between:
1) Reflector & Driven Element = 730 / F (MHz)
2) Driven Element & 1st Director= 600 / F (MHz)
3) 1st Director & 2nd Director = 600 / F (MHz)

Enter the formula for the antenna calculation
Divided by Freq MHz


Total wire-length in feet is FEET.
Total wire-length in inches is INCHES.
One of four sides in FEET = <- Use ONLY this number for "element spacing" when entering the element spacing numbers (constants; 730 or 600) above!
Total all spacing measurements (in inches) then add 2 inches for each end.


THE QUAD SHOWN BELOW IS AN EXAMPLE OF A QUAD DESIGN USING DESIGN-A-QUAD ABOVE


The number "1" HAM station, field-day, and contesting, wire type antenna in the world today.
The Windom is an antenna that enables operation, 80 through 2 meters, without an antenna tuner.

By G. E. "Buck" Rogers Sr(60+ years as K4ABT)

VHF was fun, but most of our enjoyment was on HF;  September 1949, I was exhausted from climbing poles and trees to move, remove, add, or change my single-band HF antenna's.

The trick of it all, was to remember and change the plug-in "tank-coil" to match the antenna band.  My ole 807 rig was a home-brew, that I had built on an old Atwater-Kent radio chassis.  I had wound the tank-coils on phenolic, plug-in coil forms (No, it was NOT a pi-section, tank-circuit, it was a real, sure enough, link coupled output, no less).

I won't forget the day and all the jumping up and down by some SWLs who were listening on another band.  I had my 80 meter (3735 kc, now called kHz) crystal plugged into my homebrew rig, with the antenna connected and away I went to make some serious early morning CW contacts on 80 meters.

CAVEATE:  The night before, I had been operating 40 meters.  This morning, I wanted to make some 80 meter contacts.... BUT, and However, I forgot to change the "plug-in" tank coil from the 40 meter plug-in, to the 80 meter coil. 

By forgetting to change the 40 meter plug-in coil to the 80 meter coil, I had doubled in the final.... and the 3735 rock, had put my RF signal output on 7470 kHz. 

YES! you bet I got a letter... matter-of-fact, I received a "Show-Cause" notice from the FCC monitoring station at Powder Springs, Georgia, and furthermore, I received a letter from an OO in Delaware.  Never again, did I forget to switch the plug-in tank coil when I changed bands... moreover, I made sure the crystal I was using was for the band I was operating on.  To help me remember, I made an entry into my log book of each band change, and a check-mark to indicate that I had indeed changed the tank-coil to correspond with the crystal frequency.

Atenna tuners were few and far between. This being the case, it's a good thing the more up-to-date transmitter's used Pi-Section output tuning. Yes, I wrote, "transmitter's;" Transceivers were unheard of in those days.....  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.

Enter; THE WINDOM:  Call it what you like, OCF, OCFD, or the name for which it is named... its namesake is Windom.  The Windom was, is, and will be the number one antenna in the world for many years to come.  The Windom was first designed in 1923.  It was fed by a single wire (coaxial cable was not around in those days),  The designer William Litell Everitt (his photo is shown elsewhere on this page), brought it to the world in 1923, and later wrote a brief about it in 1926.

A detailed article by Loren G Windom, W8GZ  written in the September, 1929  issue of QST Magazine.  The Windom gained it fame then and many times through the following years.   I had heard of the "Windom" and read a few articles about the Windom, but most of my thoughts were ... ho-hum.. just another off center fed (OCF) dipole fed a bit off-center.

Then one fall evening in 1949, at a meeting of the GARC in the old "Sea Scouts" club house near the Coosa River in Gadsden, Alabama;  I listened as some of my "Elmer's" discussed the Windom all-band HF antenna.   It was when Jack Kennamer, (W4YPC) (SK), mentioned using one (Windom) antenna on all HF bands.... without an antenna tuner...! my ears went directional !

That last phrase caught my undivided attention. "all HF bands, ..etc" What ! A multi-band HF antenna? Surely I had been blessed.

To think that I could hang 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 (1945-1949), a BALUN was unheard of.  My Elmer's described, a means of connecting the coax to the off-center fed antenna using a lossy, 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.  Later I began to study something called a "BALUN."

In 1958 I read more papers by Gillette Guanella which referenced a “current” type BALUN.  then I came across  Thomas O’Meara’s papers, “Analysis and Synthesis with the ‘Complete’ Equivalent Circuit for the Wide-Band Transformer.”  This is when I made some changes to the design of the Windom antenna.  In 1970, I met Lew McCoy W1ICP (SK).  We talked about the Windom antenna and how we were building them.  Lew had some ideas that we felt had merit enough to give them a try… walla, almost like magic, Lew's current type BALUN design gave us the bandwidth that we needed to make the WINDOM into an eight (8) band plus antenna (even adding some VHF bands).

FOR THE RECORD:  We have heard that some of our competitors are spreading false notions about our BALUNS and antennas:  For the record; Our BUXCOMM Windoms have specially designed "Broad-Band Baluns"  using multiple cores and  Teflontm covered, silver-flashed copper wire.  These BALUNs enable operation from 1.5 mHz, well into the VHF region. Internal BALUN connections are made using silver-bearing solder.  Except the special request BALUNs (with eyebolt terminals), all BUXCOMM BALUN's have large, right-angle, side screw termionals made of Brass.  The purpose of the right-angle, side-screw antenna connect points is to enable antenna feed points connections without turning the terminal connector.  Another purpose of the bronze bearing Brass stud is to enable the user to solder directly to the ring-terminal screw or to the stud itself.

It does not matter whose BALUN you use; PLEASE, Please seal all terminals and appendages in or out of the BALUN with Coax-Seal CS 104.   It does not matter whose BALUN you use, NO ONE makes a BALUN that is impervious to driving Rain.... sooner or later, it will fail because of moisture ingress.  If you don't wish to seal all the3 BALUN terminals, then drill a 1/8 inch "weep" hole in the bottom of the BALUN.

UP CLOSE, dealing with the reality of ground influence: Pay close attention to what I'm about to say.

l      Impedance at the feed point of the Windom (or any wire type antenna) decreases at resonance as the height above ground decreases !

or to say it vice-versa.... and still have the same meaning or result:

l      Impedance at the feed point of the Windom (or any wire type antenna) increases at resonance as the height above ground increases !

Having made this statement, I should clarify how we arrived at this axiom.

Here in the BUXCOMM lab and our antenna farm, we made many tests with the Windom at various heights above ground.  After many, and I mean "many" trials with the Windom at various heights above terra-firma, we found optimum performance at thirty-three (33') feet above ground while using a 4:1  BALUN at the feed point.

When we raised the BUXCOMM Windom above 35 feet (raised to 55') we found the feed-point impedance at 75 meters rose to 266 ohms.  To make our Windom appear at a more constant impedance, at the same operating frequency, we made a change in the BALUN ratio from 4:1, to 5:1.  With our 5:1 BALUN (model B15KC51), the impedance at resonance remained fairly stable when our Windom is 50+ feet above ground.  When in doubt, use the following rule-of-thumb to match/balance your Windom and BALUN;  

Antenna height above ground:

BucK4ABT

*  No test results available above 70 feet


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 (lossy) 9 turn, 8 inch diameter, decoupling loop.

As I soon learned, this is one of the best and least expensive HF multi-band antennas ever made. It appears as an off-centre-fed (OCF) dipole. This off-center fed design is actually the way the first Windom antennas were designed.  The short side of this story is:  the early Windom's were fed with a single wire (non-coaxial) which allowed the RF to radiated freely inside and outside the HAM shack.

UPDATING THE "ORIGINAL" WINDOM:

Using an open-wire feeder from the transmitter to the antenna was somewhat dangerous when running power levels above 50 watts. This is in difference to today's rules regarding RF radiation exposure, so to prevent this radiation by the feeder wire, we have adopted the use of coaxial cable to feed the Windom antenna. In order to do so, we had to move a bit further away from center than the designer of the Windom had.

Instead of using a 330 ohm feed point on the Windom (approximately 14% offset from center of the antenna and with the Windom more than 55 feet above ground), we found a more suitable feed point that was closer to 33 percent off-center. This point comes closer to being a 233 ohm feed-point, and since we adapted the Windom for coax feed, we now use a 1 to 4 (B15C41) current BALUN when our Windom is 25 to 35 feet above ground, and a 1 to 5 (B15C51) current BALUN when our Windom is 40 to 55 feet above ground.

With the offset at one third (1/3) distance from one end, we find the Windom has a median impedance of approximately 223 ohms. This impedance is more practical for using a 4:1 BALUN at the feed-point.  In order to use a 6:1 BALUN and achieve a close impedance match, we must move the feed-point further away from ground.

With the use of our Windom antenna, many customers will order the 6:1 BALUN because a friend told them to do so. These are customers who are sometimes misled by the unknowing. The 6 to 1 BALUN is OK when employed with the Windom feed point above or more than 55 feet above ground.  HOWEVER, we no longer use that 14 percent center offset.  We have moved to a more desirable feed-point (33 %) offset, and use a 4:1 BALUN (20 to 40 ft above ground or a 5:1 BALUN when we have the Windom feed-point 40 to 55 feet above ground.  When in doubt, use the 4 to 1 BALUN.  In either case, the 4 to 1 and 5 to 1 BALUN's are more efficient than a 6:1 BALUN.

Using a 4:1 or 5:1 BALUN at the feed-point of the Windom antenna, we can operate without the use of an antenna tuner. The Windom is an uncomplicated, easy to use, harmonic related antenna. If we are the owner of an antenna tuner then by all means use it.  Since I run 200 watts (or less) I for one don't like the idea of placing too many obstacles in line with my antenna, because each transition from one feed-line, tuner, or other transmission line transformer simply adds more losses into the equation and thus reduces this wonderful antenna's high performance.

It could be that many young hams ignore the multi-band Windom antenna because of its sheer simplicity and may think it's too good to be true.  Think about it, and while you are doing so, remember, the more trinkets, and unnecessary inserts that are placed into the RF path to the antenna are simply "window-dressing" or gimmicks.  These added "gimmicks" become an obstacle or loss to that extra bit of RF signal that could have made that rare and needed contact in a contest pile-up.  The original coax cable fed Windom has proven itself over and over, to be the number one wire type antenna with the most versatile and valued performance record in the HF communications world.

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."  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. 

Remember the axiom:
"When you have achieved perfection, anything more becomes a point of diminishing returns." Enough said!

Trust me on the above paragraph, as I have experimented with every Windom and Jpole concept or design that can be imagined. Having built and sold thousands of these two antennas, I've found that It's difficult to improve on perfection.

80 through 2 meter WINDOMs are complete and factory assembled and tested.↓

Similar to WINDOMs shown above, These WINDOMs are completely assembled, ready to connect the coax, and erect. BUXCOMM Windoms are power rated at 1000 watts SSB and include all insulators, high-tensile strength, super flexible PVC covering, Power-Flex, tinned, copper wire, connectors, and BALUN. Our High-power versions are rated at 2000 watts and are identified with an "HP" in the model number. See coaxial cable and related items below. You can be on the air in no time, with any of our Windoms.
BUXCOMM Windoms are the choice of Hams, World Wide


 

Figure D

The Windom can be installed as a Droop-End (see figure D below) or as a sloper, but in no case, should the angle be greater than 90 degrees against itself. To use an angle that folds against the pattern of the opposite end, or the feed line of the Windom, could change the impedance of the feed-point, change the multi-band features, and most important, destroy the radiation characteristics of the antenna.

 A touch of Class,  The Windom and the J-POLE
By Glynn E. "Buck" Rogers Sr (60+ years as K4ABT)

The J-POLE has been around since the early days of HAM Radio, and is a direct descendant of the "Windom" Like the Windom or ZEPP, the J-POLE is a spin-off, or a modified WINDOM for VHF and UHF. One of the first articles I wrote about the J-Pole was in HRC magazine in 1958. Since 1958, I've written several j-pole articles in other HAM Radio publications.  Here, my references are to the early, 1923 (version) Windom (Article by Loren G. Windom September 1929, QST magazine) .

If you look at the feed method for the early Windom, it was fed with a single wire.  You soon see the similarity between the Windom, ZEPP, and the J-Pole.

Look close at the configuration of the Jpole and the Windom, and you will understand why in many of my articles in CQ Magazine and other publications, that I often refer to the Jpole as a Windom, with the short section folded back on itself to form the parasitic element. It is for this reason that I feel these are two of the best antennas ever designed.  Having said this, you will also note that the Windom (and the Jpole) are powerful antennas that provide outstanding performance on all bands above the band for which they are cut or designed for.

The reason these two antennas perform so well (as Multi-Band antennas; Windom for HF & lo VHF, Jpole VHF & UHF), is because they operate at harmonics of the fundamental or lowest frequency for which they are cut/designed.  To add additional feeders (ladder-line),  other than 50 ohm coax or UNUNs is a waste of RF energy. Only 50 ohm coaxial cable and a BALUN at the feed-point is all that is necessary. Anything more, add losses into the equation that cannot be overcome after-the-fact. See "frequency vs wavelength" and "ham-band, harmonic relationships" in the following color-coded chart. 


From: Richard Soikkeli
Sent: Monday, May 19, 2008 11:35 AM
To: support@buxcomm.com
Subject: Thanks for your fantastic Windom antenna!

Dear Buck,
Thank you so much for your patient technical help and the Buxcomm Quality windom antenna.   2 weeks ago down came the 102' G5RV and up went the 802136 BUXCOMM Windom. 

Now I am filling the log book with countries I rarely could even hear before, much less work, even with 500w CW.  I have "busted" some pile ups with a first or second call and got real 599 rpts from DX over 8000 miles away.   The low noise factor and gain does the trick.  Also, I don't have RF into my son's computer speakers any more and I'm sure the neighbors are happier. 

I am advising our Field Day team to ditch the g5rv's as they don't compare at all as you told me would be the case.  I only wish I had heard about BUXCOMM Windom's sooner and had more fun working DX over the years.   I just installed a 2nd windom for my jr. high ham station.  Now its time to break out the QRP rig and see what it will do too.  I will be ordering more parts soon.

  73 and thanks again, Rick  AE6RS 

To manage both CW and Phone portions of the HF bands with the Windom, some "pruning" of the elements L1 & L2 can be made. Pruning (reducing) the length of L1 & L2 may cause an increase in VSWR at the lower ends of the band(s). Always remember to make the cuts proportional to each element. If you remove 12 inches (1 ft) from L1, remove only six (6) inches from L2.... If you remove 2 feet from L1, remove one (1) foot from L2. Do not remove more than 3 feet total (L1=2 ft, L2=1 ft)

The Windom above is cut for the CW portions of the HF bands.

For the technical minded Windom builder, we opt for the 4:1 BALUN because it is; more efficient, and weighs less. Another nice feature we found using our Rhode & Swartz Antenna Systems Analyzer, the Windom exhibits similar feed-point impedance across the bands from 75 through 6 meters.

A word to the wise.... NEVER make any angle of the Windom (or any flat-top antenna) more than 90 degrees. Ends can hang down, from a horizontal plane, but do not allow the angle to be tighter than 90 degrees e.g. 75, 45, degrees etc. A Windom may also be installed as an Inverted Vee, as long as the Apex (Point where BALUN feeds the Windom) is not sharper than 90 degrees. The Windom is suitable for mounting as an inverted V, supported between two masts, tower, or trees. The Windom wire elements must not come in contact with limbs, vegetation or metal objects.  In practice, try to keep both ends (wire elements) of the Windom three (3) or more feet away from any limbs, vegetation or metal objects.

The BUXCOMM Windom can be purchased in several different band or lengths. The number of bands covered is determined by the length.

The 160 thru 6 meters version is approximately 260 total length. BUXCOM P/N 166260 With Current BALUN attached The 75 thru 2 meters version is approximately 130 ft total length. BUXCOM P/N 752130 With Current BALUN attached The 80 thru 6 meters version is approximately 137 ft total length. BUXCOM P/N 802136 With Current BALUN attached The 40 thru 6 meters version is approximately 66 ft total length. BUXCOM P/N 40670 With Current BALUN attached The 20 thru 6 meters version is approximately 37 feet, total length. BUXCOM P/N 20634 With Current BALUN attached

AN UPDATE:

Since writing this article several decades ago for a major HAM radio magazine, I've received tons of mail (and eMail) asking for more information, especially with regards to my 160 meter version;

The BUXCOMM model 166260 Windom antenna is a horizontal wire, multi-band antenna intended for use without an antenna tuner on 160, 80, 40, 30, 24, 20, 17, 15, 10, 6, abd 2 meters. The WARC bands of 30, 17, 15, and 12 meters by using an antenna tuner. The antenna wire is made of 61 strands of silver flashed wire and covered with non-metallic, super-flexible PVC insulation. Each end of the BUXCOM Windom’s have end insulators made of high tensile strength TyNYTE. The Center insulator is also Tynyte, and is fed by customer’s choice of either a 4:1 or 6:1 BUXCOMM MasterMatch BALUN transmission line transformers. The BALUN feed is attached near the one-third offset point according to the feed-point required by the BALUN ratio (200 ohms/4:1, 250 ohms/5:1,or 300 ohms/6:1). By using a different feed-point for 4:1 BALUNS, a slight increase in antenna efficiency is realized when using the B15C51 (243 ohm) feed which results good VSWR on all referenced HAM bands. The antenna is suitable for mounting as a dipole, supported between two masts, tower, or trees.

The Windom wire elements should not come into contact with any limbs or other vegetation. Here's why;

The sky-blue insulation on the wire elements of our Windom antennas provide esthetic blending with surroundings, added tensile strength, and most important, it prevents oxidation of the wire. Oxidation can wreak havoc after a few years exposure to the elements.

A few new HAMS do not understand why we advise against allowing the wire elements (although insulated) to come in contact with metal objects, tree limbs, and similar vegetation. Here, insulation does not prevent "proximity influence (added capacitance), and RF absorption" by nearby vegetation, be it limbs, or metallic objects. The same thing happens when the "sap" is up in the limbs, as happens when the antenna elements come in contact with, or near metal objects; stray capacitance, both inductive and capacitive will surely detune a well engineered antenna

The BUXCOMM Windom’s may also be mounted as an "inverted Vee". Do not exceed 90 degrees when erecting as an "inverted Vee". Specifications: Frequency range: 1.8 – 2.0 MHz 3.5 – 4.0 MHz 6.8 – 7.4 MHz 13.9 – 14.7 MHz 27.8 – 29.8 MHz 49.5 – 54.0 MHz Feed-point Impedance 50 ohms VSWR <2.0:1 Horizontal Polarization (If suspended as an Inverted Vee, do not exceed 90 degrees) Maximum power 1200 Watts SSB, 750 W AM/CW, Wire Length model 166260 = 260ft. WARC bands of 30, 17, 15, and 12 meters by using an antenna tuner. Now-a-days, I see a lot of knock-offs of the windom, they even try to change the name or use acronyms and try and relate it to the dipole. The Windom is still a Windom, regardless of what they call it.  As with the "apple." The apple is still an "apple" regardless of what other name they try to give it!

Having said that: 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)

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. Although it was first build and tested by William Everitt (see photo), 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 200 Ω to 50 ohm, (4:1) balun in its feedpoint and fed with coax.

In recent years, some operator's are using 300 to 50 ohm, or 6:1 baluns. They base their decision on the simple math that the feed point is three (3) ohms closer to 300, than 200, simply because the feed-point of the Windom is 243 ohms nominal. Has anyone ever heard of "surge-impedance?" In tests, we've found, there's no significant difference in performance either way. Therefore, the trade-off is a matter of personal choice. Mine of course, is the Windom with a 4:1 Current BALUN (B15C41 or B15C41XV). If you plan to run more than 1000 watts SSB into our Windom, we suggest you request our Windom with the B15C41XV Current BALUN rated at 1.5kW SSB.

Here are some final notes:

In our BUXCOMM BALUN's, we make it a point to polarize the posts of our MasterMatch series, identified by a RED or BLACK dot, or ring on the brass terminal posts. This provides the user with a benchmark that allows the BLACK post to be used towards the "cold" side of the antenna and the RED post is connected to the long, or "hot" side of the antenna. Some old-timers of my vintage, refer to the cold side of the antenna as the "parasitic" element.

As a point of interest, in some installations, the coax feed-line may pass through the RF field of the antenna, RF current can be introduced into the feed-line after the balun. In this situation, a 1:1 Current Choke should be inserted into the feedline near the feed-point of the antenna.

A few notes about "SkyWires" or, the full-wave Loop Antenna

Loop antennas have a fairly low impedance when they are built one (1) wavelength in circumference. The low feedpoint impedance at harmonic multiples of the resonant frequency as opposed to dipole antennas, have low feed-point impedances at ODD multiples of the resonant frequency.

When a Full-Wave Loop is operated near resonance on the desired band, a 5 to 1 or 2 to 1 balun works very well, when using 50-ohm coaxial cable to the radio from the balun, VSWR at resonance will normally be below 2:1. An external antenna tuner is not required.  If necessary, the transceiver's internal antenna tuner may be used.

Typical SWR Plot of full-wave horizontal loop at approximately 40 feet above average ground using BUXCOMM MM21, 2:1 balun should exhibit an VSWR at resonance below 1.5:1.

Application Notes for BUXCOMM BALUN`s

Definitions: BALUN = Asymmetrical to Symmetrical;   UNUN = Asymmetrical to Asymmetrical

1:1 BALUN: 50 ohms to 50 ohms, or to feed dipoles and similar antennas with 40 to 75 ohm feed points.
BUXCOMM model MM11

1:2 BALUN: 50 to 100 ohms. This Balun is suitable for feeding Vertical Antennas, Quads, Loop antennas and  Ladder Line antennas.
BUXCOMM model MM12

1:4 BALUN: 50 to 200 ohms. This Balun is suitable for the coupling 50 ohm coaxial cable to Windom’s, and off-center-fed antennas.
BUXCOMM model B15C41

1:5 BALUN: 50 to 250 ohms; Suitable for coupling 50 ohm coaxial cable to a Windom’s, when the Windom is more than 50 above ground.
BUXCOMM model B15C51

1:6 BALUN: 50 to 300 ohms. This BALUN is suitable for the adjustment to asymmetric fed dipoles such as Windom’s, G5RV, and zepp antennas. The BALUN is fed directly to the Windom and similar antennas. With double-zepp and G5RV antennas and use of asymmetrical feeder, the BALUN is positioned before entry of the cable into a building.
BUXCOMM model B15C61

1:9 BALUN: 50 to 450 ohms for coupling Asymmetrical to Symmetrical feeders.
BUXCOMM model MM91

1:9 UNUN: asymmetrical to asymmetrical (unbalanced to unbalanced) Long wire antennas, Ground Plane`s, Verticals, and some types of "beverage" antennas,.. etc.
BUXCOMM model MM19LW

1:16 UNUN: Similar to above application; asymmetrical to asymmetrical (unbalanced to unbalanced) Long wire antennas, Ground Plane`s, Verticals, and some types of "beverage" antennas,.. etc


An Improved G5RV Antenna:

The original G5RV antenna was developed by Louis Varney G5RV for 20 meters. Although his design was a good one, he used the 450 ohm ladder line as a feed-line-to-antenna impedance match, and without the use of a BALUN. We discovered that feeding the 450 ohm ladder-line directly with an antenna tuner, left us with a shack full of RF…HOT mics, hum, and in some cases, we had "squeals" from rectified RF getting into the microphone audio path, within the transceiver, a sure sign of RF-Feedback (base rectification).

To make the G5RV more "user-friendly" and with less RF exposure within the HAM-shack, we added an MM11 BALUN at the lower end of the 450 ohm ladder-line, and from the asymmetrical input of the MM11 BALUN (outside the HAM shack), we used 50 ohm (low impedance) coax to reach the antenna tuner inside the HAM shack. We’ve found that this improvement to the G5RV has put more of our transmitted RF into the elements of the antenna, and made the antenna virtually noise free and reduced re-radiation as much as 85 percent.

Without using an external antenna tuner, we’ve found that our transceiver will work into the 50 ohm coax and the MM11 BALUN with VSWR below 2:1 on the bands the G5RV is cut for.

By making the additional BALUN and coax improvement to the original 20 thru 10 meter G5RV, it is now possible to build the G5RV for more bands, and thus cover lower bands and frequency’s. We now have a means by which we can have an antenna that fits almost any real-estate configuration, from as little as 27 feet (8.2 m), (20 thru 10 meter bands) to 207 feet (64 m) (160 thru 10 meter bands).

BUXCOMM now builds G5RV antennas in four (4) versions and lengths. Depending on your available space, you may choose the size and version to fit your needs and available real-estate space.

Model 80 thru 10 meter band coverage; Overall Length BALUN    

G5RV-16010 160 to 10 meters 208 feet or 63 meters

G5RV-8010 80 to 10 meters 102 feet or 31 meters MMG5

G5RV-4010 40 to 10 meters 52.5 feet or 16 meters MMG5

G5RV2010 20 to 10 meters 26.5 feet or 8,1 meters MMG5

Here's more commendation for our BUXCOMM Windom antennas:

From: M33Access Sent: Monday, October 16, 2006 2:55 PM To: support@buxcomm.com Subject: BUXCOMM WINDOM

Hello

I couldn't resist the opportunity to tell you about your Windom antenna I bought a couple weeks ago. I have been off the air for a number of years. Probably close to 15 to be exact. My oldest son got his ham ticket this past summer and started buggin me to get on the air. That's when I decided to bite the bullet and get on.

After working for days trying to make my old "Inverted V" work. I turned to you folks and your off center fed Windom. Since then I hung the antenna at the 70' mark on my tower and the long end to about the 55' mark on a tree in the back yard. My station is simple, I use the Kenwood TS-180s barefoot to the Windom. I love to work rtty and packet. I am using an ancient AEA Pakratt232.

I have heard DX that I never heard in my years of being a licensed Ham. I have worked Italy, England, South Africa and last night I worked a station in Chile. CHILE! Now that is at the other end of the world! This is so neat, I can't tell you how much I am loving your antenna. Remember this is barefoot. I have my dad's SB-230 amp, but it's not hooked up. I don't have the DIN plug for my 180 yet.

If you have customers asking how your BUX Comm Windom antenna works, give them my call and I will be happy to meet them on the air.

73, and thanks again.

Bob WB8UJB

From: Andy KA3ODJ

Sent: Wednesday, June 07, 2006 6:49 PM To: support@commparts.com Subject: 166261W100 Just wanted to let you know that your 166261W100 antenna here at KA3ODJ is working like Gang Busters. Purchased the antenna primarily as a 160 Meter antenna for the Internet Remote Base. The SWR and performance exceeded what I had expected, I have added it to the selection choices for the other bands. Can not wait to get the ends up higher, they are only 35" or so right now. Getting good reports from the users of the Internet Remote Base. No RF Problems at the coax end either, I also am using one of your Master Match at the antenna switch. I am running an Icom PW1 and in the past, I've had RFI issues in the shack resetting the computer, but no more, with this new BUXCOMM Windom, it's clean as a whistle. Feel free to give your antenna a try if you like. To operate Remote, You will have to download W4MQs software to get access. http://wpmq.com. Thanks for a great product at a fair price. Andy KA3ODJ

Our Windom Measurements

Freq mHz

1.9

3.5

7.1

10.7

14.2

21.4

28.5

SWR

1.8

1.2

1.8

1.55

1.33

2.1

1.25

Impedance

233

218

158

161

280

256

190

Metric Conversion

INCHES

To Millimeters Inches x 25.40 To Centimeters Inches x 2.54 To Meters Inches x 0.0254 From Millimeters M x 0.03937 From Centimeters C x 0.3937 From Meters M x 39.3701

FEET

To Millimeters Feet x 304.8 To Centimeters Feet x 30.48 To Meters Feet x 0.3048 From Millimeters M x 0.00328 From Centimeters C x 0.03281 From Meters M x 3.28084 From Centimeters C x 0.01094 From Meters M x 1.0936

YARDS

To Millimeters Yards x 914.4 To Centimeters Yards x 91.44 To Meters Yards x .9144 From Millimeters M x 1.094 x 10- 3 From Centimeters C x 0.01094 From Meters M x 1.0936

 WINDOM, to ZEPP, to VHF J-POLE.

BUXCOMM BALUNS are more than just antenna matching devices:

* Help keep RF out of the shack.

* Provides maximum transfer of RF to the antenna.

* Elemination of radiation from the feeder cable

* Makes the antenna radiation pattern predictable.

* Reduces QRN and TVI to the neighbors.

BUXCOMM 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 Line-Isolator BALUNS may also be installed anywhere along the cable to prevent the destructive influence of induced RF currents (VSWR).  The best location for the BUXCOMM LISO is to install it at the output of the transceiver or between the linear and the coax cable feed line to the BALUN at the antenna.

The illustrations, drawings, and documentation shown on these pages are for use at the readers
discretion and is NOT a recommendation by BUXCOMM Corporation, its owners, or employees.

Noise is the enemy of Packet, Voice, Data, and Digital Communications.  In addition to providing Equipment and Personnel Protection
from lightning, a good ground system will reduce noise in your Packet Station, or your mountain-top communications site.

G. E. "Buck" Rogers Sr.


If you follow these Lightning Protection & Grounding procedures
YOU'RE GROUNDED!

ANTENNAS AND SUPPORTING STRUCTURES

Metal antenna structures that are anchored into the ground are inherently self-protected. Some radio systems antennas and beams may be unlikely to be damaged by direct lightning strokes, but they should be bonded to metal supporting structures to eliminate arcing. If the ability of an antenna to withstand direct lightning strokes is doubtful, Lightning rods atop the tower or supporting structure, to intercept strokes should be provided where the transmission pattern permits.

Lightning rods may be attached directly to a metallic supporting structure and should protrude sufficiently above vulnerable elements to provide an adequate "cone of protection". Top lighting fixtures may also be subject to damage if they are not properly shielded. Metallic antenna towers, either guyed or self-supporting, provide an excellent conducting path for stroke currents but the footings, base, and guy anchors of such structures must be properly connected to suitable grounding electrodes.

When wood poles are used to support antennas a lightning rod should be provided at the top of the pole to intercept strokes.  This lightning rod should have a large size ground wire cadwelded to it and routed to a good ground system. This will give protection against pole splitting and possible antenna damage.  In a common arrangement, a ground rod is attached to the pole with one end protruding sufficiently above the top of the pole to provide a suitable cone of protection.  A #6 AWG (or larger), solid, bare copper, down conductor is connected to the rod and stapled directly to the pole on the side opposite the coax or transmission line to the antenna.  All pole-top hardware, the antenna, and any supporting guys should be bonded to this grounding conductor.

At the base of the pole the shields of lines, equipment cabinets, and any other conducting objects should be bonded to the down lead which then must be connected to the common area ground system similar to that shown below.


An overview of how a communications site is grounded.

Your site should not contain an independent ground(s). ALL grounds should be connected together as shown in the illustration above. A single point (common) ground is noted by the Master Ground Bar or MGB, as shown.   Ground rods are chemical rod systems that are used in areas where grounds are hard to achieve.

The drawing above is a "cut-away" that illustrates how the chemical "L" ground is installed.   Chemical ground rods are also available in straight or "vertical" shaft design.


NOTICE:   When working around electrical earth or signal grounds, Never intrude, interfere with, or interrupt, any part of this ground system.  Above all, do not "break" or open your electrical power ground.   In no way should you compromise your electrical service grounds!  When in doubt, call or consult your utility company and a licensed electrician.

Remember, lightning is unpredictable.  A direct lightning strike or a nearby hit/strike can damage your equipment.  In addition; It can cause injury to those near the strike, start fires, or cause death.  Again; When in doubt, call the local utility company or consult a licensed electrical contractor or specialist.


For those who want top level lightning protection, here are a few of the current generation in lightning protection devices.

A Secondary Lightning Protector

Remember the axiom; "An ounce of prevention is worth a pound of cure."  This lightning protector contains a modified spark gap that provides that ounce of prevention.  We offer this device as a secondary radio protector.   Remember, there is no substitute for a good earth ground, AC line surge, and spike protection. 

Keep all ground leads as short as possible.   Where lightning is involved, we make no warranties.
 OrderLine Only; toll-free 1 866 300 1969 Monday > Friday 9:AM to 4:PM,  eastern time

  7516

Remember the axiom; 'An ounce of prevention is worth a pound of cure.'  This lightning protector contains a modified spark gap that provides that ounce of prevention. . Remember, there is no substitute for a good earth ground, AC line surge, and spike protection. Where lightning is involved, we make no warranties. We offer the 7516 as a secondary lightning protector. Ground wire attached to wire lug.

Power line Surge & Spike

Suppressor, with three Outlets,

and all three are MOV

protected.

 "Don't plug it in without protection !"

 

Lightning and power surges can permanently ruin your electronic equipment. Changes in voltage can cause lockups and loss of work and data. This device will protect your equipment from the threat of bad power. This Surge Arrestor offers a great value for high-end home and business equipment applications such as home and office computers, expensive HAM gear, high-performance stereo equipment, printers, appliances, televisions and more.

 

Order  3OUTMOV
$ 3.95 ea

 OrderLine Only; toll-free 1 866 300 1969 Monday > Friday 9:AM to 4:PM,  eastern time
 

Order  3OUTMOVX10
10 for $ 29.95

 OrderLine Only; toll-free 1 866 300 1969 Monday > Friday 9:AM to 4:PM,  eastern time


FYI... No inline device will protect against a powerful, direct lightning hit.



The industry "work-horse" is the model 3710 (and 3730) Ground Tester. I consider my model model 3730 to be one of the most "user friendly" devices that I have ever used to test an existing ground system at communications sites. 



 OrderLine Only; toll-free 1 866 300 1969 Monday > Friday 9:AM to 4:PM,  eastern time


 

Digital Ground Resistance Tester Model 4610
(When it comes to making ground measurements and soil resistance tests, this "magic box" is my first choice!)

  • Measures from 0 to 1999 ohm
  • Direct reading bridge
  • Fall-of-potential method
  • Autoranging
  • Measures Ground Resistance (3-point) and soil resistivity (4-point)
  • Step voltage tests
  • Touch potential measurements
  • Continuity tests on bonding
The model Digital Ground Tester Model 4610 performs accurate ground resistance
measurements (3-point) on single rods or computer grids, and soil resistivity
measurements (4-point). It may also be used for step voltage tests and touch
potential measurements.

The model Model 4610 is autoranging: It will automatically seek out the optimum
measurement range. To use the tester, simply connect the leads, press to
measure, and read. This rugged, easy-to-use tester is ideal for maintenance
crews performing multiple and repetitive tests.

Here are some rules of safety that could help save your life if lightning threatens.

  • Stay indoors, and don't venture outside, unless absolutely necessary.

  • Stay away from open doors and windows, fireplaces, radiators, stoves, metal pipes, sinks, and plug-in electrical appliances.
     

  • Don't use plug-in electrical equipment like hair dryers, electric tooth brushes, or electric razors during the storm.
     

  • Don't use the telephone during the storm; lightning may strike telephone lines outside.
     

  • Don't take laundry off the clothesline.
     

  • Don't work on fences, telephone or power lines, pipelines, or structural steel fabrication.
     

  • Don't use metal objects like fishing rods and golf clubs. Golfers wearing cleated shoes are particularly good lightning-rods.

  • Don't handle flammable materials in open containers.
     

  • Stop yard work, especially when the mower or tractor is pulling metal equipment, and dismount. Tractors and other implements in metallic contact with the ground are sometimes struck by lightning.
     

  • Keep away from water and off small boats.
     

  • Stay in your automobile if you are traveling. Automobiles offer excellent lightning protection.
     

  • Seek shelter in buildings. If no buildings are available, your best protection is a cave, ditch, canyon, or under head-high clumps of trees in open forest glades.
     

  • When there is no shelter, avoid the highest object in the area. If only isolated trees are nearby, your best protection is to crouch in the open, keeping twice as far away from isolated trees as the trees are high.
     

  • Avoid hill tops, open spaces, wire fences, metal clothes lines, exposed sheds, and any electrically conductive elevated objects.

When you feel an electrical charge; if your hair stands on end or your skin tingles; lightning may be about to strike you. Drop to a prone position immediately!


 WE Accept
NOTICE:
We ship WINDOM and G5RV (wire type) antennas worldwide, However;  Due to excessive damage, we DO NOT ship Mobile HF or Base VHF antennas outside the continental USA !

For those who want lightning protection, here is one of many, lightning protection device.

An HF Dipole Antenna specially designed with the Apartment Dweller, RV, & Field-day operator in mind.
Don't be fooled by those over-priced knock-offs that use a piece of drilled aluminum that breaks in a cold wind.  This is the original, Fixed station, RV, apartment dweller, and portable dipole from BUX Communications.  It is designed for rapid deployment and effective HF communications where space is limited.  The mounting bracket and hardware are made of high-quality, hard-drawn, aircraft aluminum, to withstand the elements and maintain a strong posture in adverse wind and weather conditions.

On a budget, Mobile in an RV, or live in a space-restricted environment?..  Here's the the solution: Here's an HF horizontal (or vertical) polarized antenna that will meet those beams "head-on!"  When installed on a rotor, this combo makes a great bi-directional fixed-station antenna.  Shown here with BUX UNUN (ONION) as the decoupling balun (unun) to prevent reradiating of the coax shield and better match at the antenna feed point.

When the stations with the gain and power in their antennas are transmitting in the horizontal plane, then you should be meeting them in the same plane.  Horizontal signals tend to follow the earths contour, and are easier to capture using a horizontally polarized antenna.  See the BUX UNUN elsewhere on this page.


BCC Photo
 
Photo above;  BUX COMM, "DBLCOMBO", see details below.
 
BUX COMM graphics 1998-2004 (c)

By combining a pair (two) of the single band HF Mobile (loaded) tunable-tip antennas, you can have an ideal, single element, (bi-directional) horizontal dipole.

  At left;  is a photo of the BUX CommCo dipole configuration using a pair of our model BHF20M mobile antennas, and our model DABRKT "Double Antenna BRacKeT."   The DABRKT will fit up to one and a quarter inch (1-1/4") diameter mast.

The supporting mast is attached to the apex of our warehouse.  Overall height of my antenna above ground is only 17 feet. When you see me on 20 meters (14.070,15 USB) running test on RASCAL interfaces, this is the antenna I am using.

 

← 
By combining a pair (two) of the single band HF (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.

Bracket alone is $16.95

tuneable-tip antennas allow adjusting for minimum VSWR.
 

or see the DBLSPCL; details below

← 
When you see me in QSO on 20 meters, using PSK31, I am using this antenna mount with two of the BHF-20 M antennas at 17 ft.  An FT-817 at 5 watts PEP, worked 50 + countries.

When installed on a rotor, this combo makes a great bi-directional fixed-station antenna.   Turning radius, seventeen feet, (approx).

HF Mobile (loaded), tunable-tip antennas

 All text and graphics on these pages are ™ of G. E. Rogers Sr and BUX COMM Corp 1986 - 2014
All drawings, photos, text, and related graphics are the property of G E "Buck" Rogers Sr.,
and may not be copied, or reproduced, in any form without the written permission of the author.

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