Author Topic: Antenna Tales,the re-discovery and modification of the W3EDP Zepelin antenna  (Read 5581 times)

Offline Carl

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  Years ago when I passed my General Class Ham license  ,I immediately began
plans for the ultimate antenna that could be light ,easy to deploy and effective ,
the kind of antenna that just forced all who heard it to reel back in awe and ask,
“What the heck are you using?”

  I tried the antenna the everyone said you had to have…a DIPOLE,but it was only
good for ONE BAND and required me to trim the ends to TUNE the already cut
to length antenna to achieve minimum SWR as I was told that an antenna HAD
to have low SWR to be ‘good’.



 Many months and many trial antennas and I successfully
turned a 1000 foot roll of 14 gauge stranded wire into a bucket of 6 inch scraps…
and still the elusive ‘perfect’ antenna stayed out of reach.



  Then ,it came to me in a dream…OK ,I read an article that said I could tie many dipoles
to the same feed point and this way work many bands with one antenna.
I made a 10 meter ,a 20 meter, and a 40 meter dipole ,actually inverted “V” as the ends
of each band pair were lower than the feed where the coax connected…SUCCESS , well sort of…
I could use 10,20,40 and 15 meters with the bowtie antenna , BUT not all of the bands and
it certainly was an ugly set of wires hanging off the pulley on my tower.



  There must be some way to do what I had for so long been told was not possible
by the numerous local ‘experts’ and build a simple,all band ,effective antenna. I moved to
testing mobile ‘Ham Stick’ antennas…they were all about 7 feet long and you had one for each band.


I tested them on a small tripod in my yard and soon discovered that they simply did not make
effective antennas or multi-band…though I did discover that the radials,or counterpoise wires did not
have to be a  full quarter wave long to be effective and followed that idea to the point of discovery of
that magical answer to all questions .SEVENTEEN…



a 17 foot wire for a ground plane worked surprisingly well ,even for 80 meters ,
where more like 78 feet  was insisted on by the math ,and the experts.

  I then thought to use a 17 foot wire and a 34 foot wire as a type of off center wire antenna
and I used a 4 to 1 balun I had as a good coax connecter and then went twice 17 for the other
side and the heavens opened and an old LDG automatic antenna tuner came into  my possession .
The 17 and 34 worked 40 though 6 meters with that tuner ,and was easy,simple ,and quick to deploy…
MAGIC WAS WITHIN MY REACH!!

Then I chanced upon a digital version of  the March 1936 QST where an unconventional multi band antenna
was described , named after the Ham who announced it, W3EDP . The W3EDP was an 84 foot wire and
a 17 foot wire with a matching inductor and capacitor to adjust the match or TUNE the antenna for the
then TUBE transmitters that worked well with little concern for matching the radio impedance with the antenna.



A more modern version uses ladder line or parallel line to feet the /counterpoise’ , that actually radiates RF,
off the ground so as to not waste transmitter power.





And so the modern adaptation of the early antenna that closely copied a popular antenna used for zeppelins
is reborn as an easy to carry and erect,effective multi band antenna that we still call the W3EDP after it’s original designer.

Many variations are now in use and a few basic ‘rules’ practically insure success.

The 17 foot wire should not touch earth and can be 34 or even 51 feet for better 80 and 160 meter tuning.

Multiples of 17 adding length to long and, or, short sides can aide gain and insure ‘tuner acceptance’

A HALF SIZE can be used for 6 through 80 meters with 8.5 feet twin lead and 33.5 feet radiator.

The flexibility of this antenna is mostly due to the antenna match/tuner and manual or automatic work
well though internal tuners of most radios do not work well as they will not match the wide variance of
 SWR needed for all bands.



Much fun can be had with an antenna that deploys so quickly as to toss a plastic water bottle over a tree
while tied to this simple all band antenna…
THAT YOU GET THE SATISFACTION OF SAYING “The antenna here is homebrew,thanks for the excellent report”

Get out and make something!



Offline DonC

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While I don't have pretty pictures to post, allow me to lend credence to Carl's post. (Not that it needs it)! Carl introduced me to the W3EDP antenna over a year ago. I put one up in my 2nd floor apartment with the ladder line near vertical and the long wire wrapped around the ceiling of my radio room, then out to the hallway, almost into the kitchen.

I started off with the magical numbers of 84' + 17' counterpoise. With all the RFI in an apartment building, it just wasn't enough. My final length was 96' + 17'CP + 34'CPL. This gave me 160-10m with little noise. Enough for me to make more QSOs than I care to count and several ragchews on a couple nets.

I enjoy this antenna so much that I made a 2nd one for portable use. I got a chance to test that portable setup as well. I attended the Skywarn Recognition Day at the Shreveport NWS Office and operated on all bands from 6pm - 6am. There were QSOs ever 3khz, I swear. Anyway, long story short, it was a successful SES! All I did was sling the long wire 20' up into a couple trees and let the ladder line dangle.

I've recently moved away from Shreveport. I plan on putting up my towers in the not-so-distant future. Until then, I'll be putting up my........ Survey says........ W3EDP!

Offline Smurf Hunter

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My problem is my home shack is upstairs, and I know from testing the ladder line portion prefers to be vertical.  I might try laying it on top of my roof this spring.

Offline Carl

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My problem is my home shack is upstairs, and I know from testing the ladder line portion prefers to be vertical.  I might try laying it on top of my roof this spring.

NO antenna is perfect,especially a multi-band antenna as compromise is a big part of antenna ,the very soil content and height above ground are
always factors along with the final configuration as to vertical,horizontal,or mix of both in orientation...the time spent with different configurations
can occasionally find that magical combination that performs well for ONLY YOUR LOCATION as the environment around you is a major variable also.

Offline Carl

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My problem is my home shack is upstairs, and I know from testing the ladder line portion prefers to be vertical.  I might try laying it on top of my roof this spring.

I also note that the first 17 foot or so vertical on even the ZIPP ZEPP (51 foot long version with 12 gauge wire,not ladder line) perform and matches faster with the tuner with the vertical orientation, even when the rest of the length just slopes toward the ground at a fairly steep angle. I have not found performance radically changed with orientation and find a 10 foot or so with the entire length horizontal works well as NVIS and has less noise on receive,Making it easier to hear stations that can get lost in the noise when vertical is compared as most man made noise is vertically polarized and the rest of the static is solar/space radiation and lightening that tends to not exhibit polarity after reflected off the ionosphere or interacting with the ionosphere. I read most of this as I lack the equipment to actually measure such myself.

Offline Alan Georges

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Video of Radio Prepper (you know, the French dude) having fun with his full-sized W3EDP: https://www.youtube.com/watch?v=OgCqLmHnpQo

Bottom line: Worked great, except on 20m where he had some trouble tuning up.  May have had something to do with wrapping the ladder line section around a tree trunk.  Also, I see that special guest R.F. Burns made a brief surprise appearance.  ;)

Offline Carl

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  I found that 20 meters,and other bands,tunes better when the 17 foot length is 25 feet long...may be a better choice as I have read a shorter length worked better for 20 meters . The original W3EDP has been something else ,even before I posted it...though I still like to credit the original design.

Offline LodeRunner

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OK, so you guys convinced me to give the 'EDP antenna a try.  I know I'd seen references to it many years ago, but had never seen a good construction article, nor any numeric/quantitative data on its performance, so had never bothered to give one a try.  But Carl's nice, clear construction notes were impossible to ignore - particularly given that I'd recently come across a ~20 ft. section of nice lightweight "300 Ohm Transmitting Twinlead" out in the garage.
I already have several 66~68 foot wires for portable antennas, so I cut the twinlead to 17'2" and shucked an inch off the conductors at each end.  I soldered short pigtails of 22ga teflon insulated wire on the BALUN end, and secured the junction with some heat-shrink tubing.  Tomorrow I'll join a 68 foot wire to the twinlead with a wirenut and hoist it up in the front yard... I have a good 4:1 current BALUN that I can borrow from my go-kit, and will go from that straight into the MFJ-259B and see what it says...  If the VSWR isn't too far off the charts, then I'll hook up a rig and tuner, and see how well it makes contacts.  Assuming it does well, I'll put a permanent 4:1 balun on the end of the twinlead, ruggedize the connection between the twinlead and wire, and it can join the other antennas in my field radio kit  ;P

Cheers



Offline Carl

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OK, so you guys convinced me to give the 'EDP antenna a try.  I know I'd seen references to it many years ago, but had never seen a good construction article, nor any numeric/quantitative data on its performance, so had never bothered to give one a try.  But Carl's nice, clear construction notes were impossible to ignore - particularly given that I'd recently come across a ~20 ft. section of nice lightweight "300 Ohm Transmitting Twinlead" out in the garage.
I already have several 66~68 foot wires for portable antennas, so I cut the twinlead to 17'2" and shucked an inch off the conductors at each end.  I soldered short pigtails of 22ga teflon insulated wire on the BALUN end, and secured the junction with some heat-shrink tubing.  Tomorrow I'll join a 68 foot wire to the twinlead with a wirenut and hoist it up in the front yard... I have a good 4:1 current BALUN that I can borrow from my go-kit, and will go from that straight into the MFJ-259B and see what it says...  If the VSWR isn't too far off the charts, then I'll hook up a rig and tuner, and see how well it makes contacts.  Assuming it does well, I'll put a permanent 4:1 balun on the end of the twinlead, ruggedize the connection between the twinlead and wire, and it can join the other antennas in my field radio kit  ;P

Cheers

As the original was designed in 1933 and little data ,beyond the joy of the multibands ease of erection ...I would enjoy seeing the "numbers" as to how bad it really is . These posts developed over time as the re development of a single antenna for multiband use with rapid deployment is really a need for the mobile prepper .

  The first was my 17 foot with 34 foot wire that worked pretty well,without caring how efficient it worked. Then came the W3EDP (actually a modified version as the ladder line was not part of the original) THEN a HALF SIZED 7  1/2 FOOT BY 42 FOOT version and THEN to enhance installation and portability I made  the 17 by 51 foot ZIPP-ZEPP from any non twisted twin lead and zip cord/lamp cord,even 28 gauge speaker wire worked ...though I would really love to see the 'numbers' on the zipp-zepp as it is my current choice for portability and it has proven effective in use (even at 10 feet above the ground in my back yard) I know it is better than the many choices of mobile whip /portable antennas ...just not how much better.



 

Offline LodeRunner

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... I would really love to see the 'numbers' on the zipp-zepp as it is my current choice for portability and it has proven effective in use (even at 10 feet above the ground in my back yard) I know it is better than the many choices of mobile whip /portable antennas ...just not how much better.

When I get a chance I'll put it into NEC and run it.  How do you configure it (horizontal | sloper | vee) and at what height(s) so I can model it properly?  Also, what kind of soil do you have in your area?

Cheers

Offline Smurf Hunter

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ease of erection

That's what she said!

Offline Carl

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When I get a chance I'll put it into NEC and run it.  How do you configure it (horizontal | sloper | vee) and at what height(s) so I can model it properly?  Also, what kind of soil do you have in your area?

Cheers

The antenna is in it's BEST when the first 17 feet is vertical and the rest is horizontal for a home station so as to get better 20 - 6 meter take off though I usually put mine all horizontal at 10 feet for NVIS duty and ease of install...two different purposes with two distinct orientations. I get fair GAIN through 40 meters on the full size 84/85 foot model and faster setup with the 51 foot length.

Note : I have also used a 25/51 foot with success though find I prefer the 17/51 length as the 3 to 1 ratio appears more stable with my tuner that the 1 to 2 ratio and I can easily make TWO antennas from a 100 foot roll of wire with even 20 gauge speaker wire working well through on air testing.

The 17 feet measure came from my kit as it worked most favorable as ,above ground,counterpoises for my Ham stick and Super Antennas as a respectable ground for fast vertical operations as I have a number of 3/8 X 24 mount antennas and mounts for most any situation.

 

Offline danimal

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An SF  18E showed me a really cool quick setup antenna he made from tent poles with bungee cord. It folded up small enough to fit in the flap of his ruck and sort of popped open in to shape. He said he'd connect it, sling it over a tree branch and get better reception than anything else weight/height/ease of carry ratio. I wish I could remember more. I think it was triangle or diamond shaped. If he had to he'd climb a tree to get it up above forest interference.

Offline Carl

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An SF  18E showed me a really cool quick setup antenna he made from tent poles with bungee cord. It folded up small enough to fit in the flap of his ruck and sort of popped open in to shape. He said he'd connect it, sling it over a tree branch and get better reception than anything else weight/height/ease of carry ratio. I wish I could remember more. I think it was triangle or diamond shaped. If he had to he'd climb a tree to get it up above forest interference.

Sounds interesting.

Offline Alan Georges

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An SF  18E showed me a really cool quick setup antenna he made from tent poles with bungee cord. It folded up small enough to fit in the flap of his ruck and sort of popped open in to shape. He said he'd connect it, sling it over a tree branch and get better reception than anything else weight/height/ease of carry ratio. I wish I could remember more. I think it was triangle or diamond shaped. If he had to he'd climb a tree to get it up above forest interference.
From your description I'm guessing that it was some variant on a jungle antenna:
https://brushbeater.wordpress.com/2015/10/15/the-jungle-antenna/
Does that picture look similar?  Anyway, pretty slick, I like the bungee'd tent pole idea.  It sure beats scratching around for suitable sticks under adverse conditions.  For the 2m band, the poles would be about 19" long, but on 440 they'd only be 6.4" long, and on 220 about 13" long.

Thanks for mentioning this.  I don't need any more projects right now, but I need a decent little 440 enough to carve out the time to make this.