What Is A W3EDP Antenna
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- เผยแพร่เมื่อ 10 มี.ค. 2018
- Fiori Films Presents Ham Radio TV: What is a W3EDP Antenna
John, WB6V explains what a W3EDP Antenna is and talks about his personal experience with it. He also touches on it's history, which dates back to 1909.
The W3EDP antenna is a design developed in 1936 and has found recent popularity with the Summits on the Air group and also Qrp enthusiasts. It was first written up in the March 1936 QST. A good technical description is also found in Practical Wire Antennas [pp. 33-34] by John D. Heys, G3BDQ.
On 20m it is 1.5 wavelengths long
On 40m it is 5/8 wavelength long
On 80m it is slightly less than 3/8 wavelength long
W3EDP might have patterned his design after the much publicized Zepp(elin) antenna that was patented in 1909 by Hans Beggerow. Early Zepp antennas were 1/2 WL long (or multiple) and fed with a 1/4 WL (or multiple) open wire feed line which uses only one of the wires. The feed line acted as a matching section for the transmitter. The antenna was typically connected to the transmitter with a tuned link coupled network. The HF antenna on the dirigible Graf Hinden- burg was 85′ long. W3EDP settled on a length of 84′ for the long leg of his antenna.
The Vaca Valley Radio Club (VVRC) has been serving the Northern Solano County area since 1988. The VVRC takes pride in providing a friendly place for radio amateurs to meet and to improve their operating skills.
Regular meetings are held on the second Thursday of the month at the Nut Tree Airport 301 Airport Rd., Vacaville. The June and December meetings are typically held at a different time and location. Please see the Events section of this web site (located on the "About Us" tab) for more details.
We hold weekly nets on the club's repeater (W6VVR) and give everyone the opportunity to request amateur radio assistance. The request for assistance can be physical such as putting up or taking down an antenna, or technical such as programming a hand held transceiver.
If you would like to join the VVRC or renew you membership this is a link to an Application Form
Browse our web site for more information about the club and what it has to offer.
If you have any questions, please email us at
w6vvr@arrl.net
or call Bob, K6HEW at 707-448-5665. - วิทยาศาสตร์และเทคโนโลยี
I use the full size and half size on my POTA activations. Easy to set up and works well.
Thanks for an interesting video clip on a very interesting antenna. M6APJ 73's.
We are glad you enjoyed it! 73 KM6FAK
I still cant figure out the LC tank. Whats the capacitance, how many turns for the inductor and how many turns for the tap?? This is necesary to replicate the design. I would love to experiment with this design.
thanks for explaining most other hams making these antennas use a 4:1 UNUN so i am getting a tad confused now
Nice Video and I agree entirely. I have a home made W3EDP antenna fed with RG58 coax on my house. Its 85' long with a 17' counterpoise. It tunes all bands from 80 through to 10m using a tee match antenna tuner. Using a home built L match it tunes Top Band (160m) and have made QSO's as far as the Czech Repaublic on our 32 watts 160m allowance from the U.K. I have made QSO's on CW as far as the Philippines and regularly make QSO's in the northern hemisphere on SSB or even AM. The only band I struggle with is 60m, but will make another tuner
. If you want an antenna that gets you on all bands although is a compromise on some, then you will struggle to go wrong with this type of antenna. No Ununs or Baluns needed and costs the price of some wire and a choc bloc connector.
73's
M0KIA
Thank You Paul! That's great news it's working that great for you. Thanks for the comment and watching the video!
The same can be done more efficiently with an auto transformer wound on a ferrite core. And fed against a good 8-ft ground rod. Putting the matching ferrite up in the air and/or using a counterpoise will pick up noise, but this can be a quiet effective antenna even on even multiples of the fundamental band thru the use of an auto transformer. No ATU or 4:1 balun needed.
Good to know! Thank you for passing that info.
At the end of the video, at around 21:53 a website Antennas X is mentioned, would anyone have a website link for this? All that I can seem to find is a bunch of sales site for manufactured antennas. Thanks de VA3NIE
I like this video
Thank You!
Thank You!
I've built a W3EDP and enjoyed the talk. I need to change the 67ft wire for somthing lighter. Thank you 2E0UKX / M6ENG
Thank You - KM6FAK
could you make that with 300 Ohm laderline for portabel use?
You are using a 4:1 Voltage balun. LDG also has a 1:1 Current balun. I am planing to use with a Xiegu G90 20w maximum. Any inputs? Thanks.
Thanks for the feedback. I will relay it to John.
I would think 300 ohm twin lead would work too. If so that would make a much smaller travel package!
W3AWH mentioned nothing about a quarter wave matching section in the canonical article from _QST_. Rather, matching was performed using a parallel tank ("It may be apropos to state here that the antenna in all cases was inductively coupled to the final power amplifier by a parallel-tuned tank circuit on all bands."), as shown at 4:20. I don't know what is being described here, but it clearly is not a W3EDP antenna.
Thanks for the feedback, I will make sure to forward it to the presenter.
It's quite a nice and informative talk by this gentleman and, despite the naysayer in the comments, it may or may not be the W3EDP antenna but who cares so long-term it works?
But I was distracted because the gentleman reminded me of Foster Brooks!
A 50 ohm dummy load for a 50ohm transmitter final will give 1:1 SWR. So YES SWR is not the only measure of an effective antenna.
Is there any actual science behind this or "blowing smoke"?
Jim Aspinwall The original zepp was designed to match an end fed half wave on a spot frequency from an airship. The W3EDP makes this multi band by adding a tuner and on some bands disconnecting the short length of wire. I have used one and it was no better than any other end fed wire. No worse either. Doing it with an open wire section might help you mount it in a better location. Overall, based on my experience a half wave end fed with a 49:1 balun will work similarly and not require a tuner. My advice to all new amateurs is to optimise for one or two bands and then change to the brands as the sunspot cycle changes. Get a resonant antenna for your two bands as high as possible. DE GM4SVM
Looks pretty much like a simple J-pole
Not really. It's closer to and end-fed that is multi band. All most all J-Pole are mono band and are just used on 70cm & 2m.