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(Repeat that title 6 times without stopping!)
Editors note: See latest updates and input at
 bottom of page for more info before you build it.

"These plans for this version of the EDZ for 6 Meters came from the previous Webmaster of the NRRL, the counterpart of the ARRL in Norway, LA2PJ, for all to enjoy and our many thanks and best wishes go out to him. This is a very inexpensive and easy antenna to build and has been used for many years in Europe by 6 Meter operators with great success!"......N4UJW

Materials needed:
About 15 feet of Zipcord (standard lamp cord #18 gauge)
Materials for end and center insulators (Your choice....Non-Conductive)
Short length of 2 inch diameter PVC pipe for winding 5 turns RG58 coax
Electrical tape, sealer, assorted hand tools
Soldering Gun and Solder
RG58 to transceiver
A handheld calculator would be handy too for the math
A little time and some nice weather!

This version of the 6 Meter Extended Zepp antenna designed for 50 ohm coax feed is made by splitting about 15 feet of zipcord (regular lamp cord wire) in half to form each half of the antenna and the short feedline all at once. When you split it you should have 2 lengths about 15 feet long each. This entire length is a little long so as to have some ends to work with when making connections to the coax and securing each half to the end support insulators. Your final length OF THE FEEDER should be cut longer than the design for adjusting SWR.( see update below)

The spreaders and center insulator are small pieces of plexiglass or any other non-conductor material you may have laying around.
They will have to be homebrewed using your own construction skills.

The short feedline wires should be separated about 3 inches from each other with the spreaders spaced evenly apart down the short length of feedline leading to the coax 1:1 balun coil.
The lower end of the homemade ladder line is soldered with one side to the center conductor and the other side to the screen or shield of RG58 coax going to your radio and sealed.
This coax is closewound with 5 turns, forming a 1:1 balun, on a piece of 2" PVC pipe and secured tightly, before it is routed down to the transceiver.
Make sure you seal the connections between the coax and the wire elements.
As with any homebrew antenna project, check your SWR using low power and trim or add to each top half for lowest reading on the frequency you will operate  with the antenna up as high as your supports allow!
"I don't know who is the originator of this design as the antenna has been around here in Europe for years." Egil, LA2PJ, Norway
Diagram below

Note - the lengths above appear to be cut for the very low end
 of the 6 meter band as used in Europe using the formulas below.
See article for suggested formulas.

Updated January 22, 2003
A little technical stuff!

Edited from latest email from Egil, LA2PJ, Norway as follows:

"My norwegian(= NORSK !!) EDZ page does not contain any technical discussion. I just state that the antenna works.
The length of the ladder-line is not random.
This kind of line will act as an impedance transformer, and you will find that matching to a 50 ohm line will take place at a point of between 45 and 50 degrees of the wavelength of the band the antenna is cut for.
I was once told to make the line an 1/8 of a wavelenth plus 10-15 percent, and then cut until you get a perfect match to a 50 ohm line, which preferrably should be connected through a 1:1 balun.

"Our" 6m version has a feeder length of 48 degrees of a wavelength.

The coiled RG-58 works as a 1:1 balun.

When the antenna is constructed this way it becomes a single-band antenna.
If you feed it solely with balanced line directly to an antenna tuner, the 6m  EDZ would also show a solid performance on 10m (probalby with fair performance at least down to 17m)."......LA2PJ

Let's design one (hopefully) using the above information:

Operating frequency 52mhz
(center of U.S. 6 meter band). Use your prefered center frequency.

We know that a full wave EDZ is actually 1.28s of a wavelength long end to end.
Using the standard formula,  (468) for a half wave, we multiply times 2 = 936 for a full wavelength.
1.28 times this  (936) = 1198 rounded off for the number to use in our formula = 1198/freqmhz

So.....1,198 divided by 52mhz = 23.03 feet for overall length.....cut in half for each leg = 11.51 feet per half or in inches = 12 X 11.51 =
138 inches rounded off per half.

Feeder Length (matching section) Calculations
Now it gets a little more difficult to calculate the feeder ladder line length. (or maybe not!)

We know by the above description that the feeder length should be about 48 degrees of a full cycle or full wavelength at 52mhz but we can't measure out 48 degrees on our tape measure so we have to convert degrees to feet and or inches.
Assuming our full wave length number that we used in the formula above (936) is correct and is equal to 360 degrees, we continue.

936 / 52mhz = 18 feet = one full wave length = 360 degrees

18 feet = 360 degrees or one full wave length.

18 / 360 degrees = .05 feet per degree.

.05 times (x) 48 degrees = 2.4 feet = 2.4 x 12 = 28.8 inches for the feeder length.

Now take the suggestion of adding 10 to 15 percent to that for tuning and we get, 28.4 X .15 = 4.26 inches added to 28.4 inches = 32.66 inches for the feeder before trimming for best SWR!
Note that we used the longer length suggestion in the formula above. (.15)

Now we know that our design must have each top half at 138 inches or 11.51 feet and our short homebrewed feeder matching transformer should be 32.66 inches before trimming.

"This example was determined by deductive reasoning using a little math with the assumption that the original design described by LA2PJ works well.
I have no reason to believe that our Ham Radio friends in Norway would have passed this design down thru the years if it was not a good design!......Please not that your installation, techniques, materials used , height above ground and other possible variables may require you to trim the antenna as needed for best performance.
As with all antenna projects, trial and error sometimes are the best teacher and the most fun!
Good luck on your design and we welcome feedback, tips, tricks, corrections, etc"......
I can't thank Egil enough for all his help in sharing this project with us and I am very glad his English is so much better than my NORSK! HI! .......N4UJW


Some authors have provided other formulas for cutting the EDZ.

They can be controversal as to which works the best in all installations.

The most common formula for the EDZ antenna is based on the long wire length formula:

L (in feet) = 984 (N - 0.025) / f (in MHz), where N = number of wavelengths, or

L (in feet) = 1205/f (MHz).

The author Beers prefers a constant of 1218, while recent editions of The ARRL Antenna Book call for 0.64 per side, which yields a constant numerator of 1258.2.....it all depends on which "experts" source your prefer!

Latest update: 09/2011
This added and very informative input below is cause for some serious rethinking of the information provided above.

From W2OZ, Skip:

Hello all, I think that the constants used in the formula are 'walking away' with sort of imbedded correction factors.

Here is what I mean. I believe that the zip cord design works, because it has been done for so long, so there is experimental merit in the final numbers. 2 5/4 = 1.25 WL, ain't no getting around this.

So it looks to me like there is a fudge factor also built into the '1.28' "constant" to correct  my suspicion of a long time error in the ARRL constant 468[234 for 1/4 W], such that 1.28/1.25 = 1.024 representing about a +2.4% correction on the long standing constant.

It is better to separate these in one's mind to avoid correcting other constants that others are already using, otherwise everytime someone goes to design an EDZ the numbers keep moving. This can be seen by 234 x 1.024= 239.616.  The 239.616 is very close to numbers found in independent experiments by many hams, and leads to an EDZ constant that agrees with other sources like Keith WB2VUO,
http://home.frognet.net/~mcfadden/wd8rif/text/zepp.txt  . 
He uses a constant of 600 per element/freq and for the entire flat top this would be 1200, amazingly close to the Norsk 1198 !  
Looking at the error factor, if there is truly a +2.4% error correction on the 468[234] in the ARRL constant then it should not be applied and reapplied, so those using 'correct constants' should only be using 1.25 for the 5/4 Wave numbers, not the 1.28.
Also there is a nagging hint of misunderstanding about percentages that makes me think someone might have wanted a 3% correction and instead of multiplying 1.25 by 1.03 to get 1.2875 instead they just added .03 to 1.25 and got the 1.28.

Why do I bring this up ? Because of 2 reasons, one if you multiply the ARRL 234 by 1.03 you get 241.++ which is even closer to many of the recent experimental constants, and when you multiply by 1.25 and 4 to get the EDZ constant, you get the mysterious 1205 ! So are we correcting a 2.4% or a 3% error ?

Other higher numbers appear likewise to be coming from the application of 1.28 on already corrected constants, like 239 and 241. The new ARRL number, looks like an 'in air' value not an 'in wire' value ie based on the 246 in air [no velocity factor applied] and then erroneously applying the 1.28 instead of 1.25 [note that .64= 1.28/2] .

I can't prove any of this, other than to restate the merits of the original experimenters correctly recording their results and trying to arrive at a synthesizing factor [1.28] based on the published standard 468 [234]. And this results in a constant of 1198 within 2 of what is quoted by Keith WB2VUO. 

I hope you can follow my thinking here. Hamuniverse.com is a perfect platform to get everyone on the same page, and help us all to have the precision in our hobby.

The WL for the length / degrees  calculation should be based on the corrected constant ie, 468[234] times 1.024 = 239.61, this will adjust the 18 FT length of the calculation above in the article.  So using 52Mhz as an example, we have 239.61 as a constant (for 1/4 wave length) x 4 (for full wave length) = 239.61 x 4 = 958.44/52Mhz = 18.43 feet rather than the 18 feet mentioned!

The use of the word 'error'..... from other sources, 'Antenna Engineering Handbook' by Jassik, the ARRL's numbers are more inclined toward 'Fat' cylindrical elements, tubing not wire, and must be corrected if used for wire, this avoids finger pointing.  'Error' can be a harsh word leading to time wasted in petty arguements while the hobby stops going forward !

The match....I won't know until I construct and measure on the AIM4170 what the results will be, but suspect that when the WL is corrected, the match will be around 45 +/- degrees with possibly an inductive stub for single band [no tuner] applications as is mentioned in the WB2VUO article briefly. There is a very excellent treatment of this type of match [BETA match] by Gary O'Neal N3GO, it is out there on the web, and moves around , on matching [correctly], the Jpole or original [single]Zepp, and the concept is very similar.

In the 2 step adjustment [coax tap + inductive stub] the coax stub is located such that the Parallel Equivalent Resistance is = 50 ohms with -J [capacitive reactance, this is NOT an SWR minimum! The AIM4170 C reports the Rp as you adjust the tap point, when the resistive component is near 50 ohms, then the inductive stub is introduced and adjusted for SWR Minimum, the AIM4170C both annonces and gives a varying pitch tone.... low tone = low SWR. Without the inductive stub the antenna will not be optimum, but very usable.  By adjusting just the coax tap point, one can arrive at the less efficient setting of Z=50 ohms, meaning that some part of the feedpoint will remain reactive preventing 100% loading on the elements.  

Next....A bit about the 6 meter band plan.

A couple of words on design frequencies; The 6m U.S. ham band true center is 52Mhz, (used as an example in the article above), but this antenna will not cover more than 700KHz, and the band is further subdivided lessening that need. 52 to 53 MHz is FM [vertically polarized] repeater inputs where most repeater users need to center their SWR so pick 52.5 MHz for vertically polarized FM if you want to use that part of the band.

The part from 53 to 54 is repeater outputs. Most repeater users never transmitt here, good SWR therefore optional.
Most Horizontally polarized emissions are from 50 to 50.5 MHz and are USB or CW.  This is where I am intending this application in a future 2 meter antenna project. European DX comes in around 50.105 to 50.115.
US calling frequencies are 50.125 , 50.2 MHz.

I will design for 50.15 or so. The freqs above 50.5 to 52 are for special uses like ATV, FM simplex ,and  AM.
Most of the high power contesting is done in the USB portion of the band.  This is where the individual hams SWR must be optimum. Hitting repeaters only takes a few watts and does not require the gain of an EDZ type antenna, however a 2 or 3 element Vertically polarized EDZ 'H' might be an excellent repeater transmitter array!
Like wise for 2m, I'm after the USB contesting portion of the band, not being 20db over into the local repeater, so I'm trying to get the SWR optimized for 144.2, and build a stacked horizontal array. Hopefully in the future, you will see it here on Hamunivere.com....stay tuned! 
73 Skip - W2OZ

Editors note...as with any antenna, there are always variables, sometimes very small, that are involved in how it will perform on the air. Many of these variables can not be accounted for in your installation by using only one single "standard formula". Remember there is NO PERFECT antenna or formula that can be duplicated EXACTLY (at least we know of none), every time, in every case using different locations, installation variables, varying material specs, space variables, height above ground and Murphey's Law.




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