Look ma, no counterpoise! An evaluation of a EFHW-8010

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by WA7ARK, Apr 24, 2019.

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  1. KK4OBI

    KK4OBI Ham Member QRZ Page

    By now the viewership is down to the hardcore. This is for you.

    The Bent Dipoles QSL site has four EFHW studies, Straight, Sloping, Inverted-V and Inverted-L. Over the past years the hit rate on these was low when the forum traffic was largely debates over Danny and his EFHW 8010. Since then the unprecedented volume of replies you folks have generated every time an end fed thread begins may have had an effect. The hit rate has climbed steadily. Every few days the Bent Dipoles site adds a thousand hits. There now are days when over 90% of these hits are EFHW.
     
  2. WA7ARK

    WA7ARK Ham Member QRZ Page

  3. PA1ZP

    PA1ZP Ham Member QRZ Page

    Hi to you all

    We have tested quite a number of homebrew EFHW antennas all of the types build by the US based My Antennas or HyEndFed compagny in the Netherlands.
    All were build with a 1 : 49 type up to 1 : 64 type transformer on FT240-31 , FT240-43 or FT140-43 core transformers.
    We never went above a single FT240 or a 2 stack of FT140-43, as if we want to go to QRO we just use traditional balanced fed zepps or balanced fed dipoles.

    We have tested the full size 80 mtrs multibanders the 40 mtrs full size multibanders and a number of shortened versions and even a few trapped versions.
    Conclusion they work well, and often better as we expected.
    We not used and tested them often above 20 mtrs but that was more due to not having good conditions and more often we almost nerver work above 20 mtrs.
    Also we have a tradition to use different types of antennas as wire antennas or other wire antennas (much smaller wire antennas) for 20 mtrs and up

    Conclusion these antennas are easy to build hang and use.
    Good way of hanging improves performance significantly like all other wire antennas.
    Hight does wonders and also very important the surroundings are very important.
    a wire antenna hanging in a very crowded city area with lots of steel reinforced concrete and street lights power lines etc will reduce performance big time, if you compare the same antenna being used in a free country surrounding with the antenna hanging free of any obstacles and conductors in or above ground.
    But they do not differ in those cases from any other dipole like wire antenna or OCF antenna.
    We almost never had any troubles with TVI or HF-detection etc, even without use of a HF-choke, in crowded city surroundings we do use realy well purpose build HF chokes ( 1 : 1 current baluns) but more for recieving purposes as for having any TX problems.

    So I can support WA7ARK findings.
    And I still have 3 different transformers to test against eachother on the same 80 meter half wave long wire.

    73 Jos
     
  4. KE4LH

    KE4LH Ham Member QRZ Page

    Hi Brian, Ok. Let's see where it goes, maybe I should start a new thread for it but I'll let you be the judge. I have been making and experimenting with a capacitive antenna of extremely small purportions for years now. And I have tested them with a friends Anritsu VNA. We decided to test one against a ground plane built for 2 meters. The one tested was a exact scaled up model of the 40 meter design I build. The reference antenna was a 1/4 wave ground plane 1 meter off the ground out of the near field in distance. We also used a Motorola service monitor with a signal tracking generator spectrum analyzer. The Reference receive antenna was a 1/4 wave dipole on the spectrum analyzer, all antennas were vertically polarized. All antennas were in the same ground plane (height), location, elevation and distance .... The spectrum analyzer was set to zero db scale on receive with the ground plane being driven from the signal generator. This was our reference setup. Upon connecting the scaled antenna in place of the ground plane a sweep of the 2 meter band indicated a 2 dbd increase in signal over the ground plane. That's 2 dbd over a dipole, or 3.+ db over an isotropic source. The tests were repeated at least 3 times, each time checking the calibration of the spectrum analyzer to indicate zero db with the ground plane. Now the fun part,.... the 2 meter scaled antenna was 1/2 inch in diameter and 1 inch long....... and a royal pain to tune because of the dimensions... but it did work, and to this day it works. On the air comparison's with 5/8 wave mobile antenna's show similar performance, and in some cases better performance. In Redwater TX, I took a portable 2 meter radio outside and tried to hit the 66 repeater in Texarkana, no dice. Put this little scaled antenna on it and full quieting contact.......

    Does that sound like something you might be interested in, or is it just "snake oil"?
    Best regards,
    Tom Ke4LH
     
  5. W9KEY

    W9KEY XML Subscriber QRZ Page

    As for me - I'm always interested in new antenna discussions. And sadly, have been guilty of hijacking a thread with a related (but somewhat off-topic) question.

    But since this thread now stands at 53 pages and doesn't seem particularity related to your "tiny antenna", I suggest you start a new thread with a proper "Subject" line allowing it to be discovered by others (now) and found in the future when searching the archives.

    Anyway - just a thought! :)
     
  6. K6BRN

    K6BRN XML Subscriber QRZ Page

    Tom (KE4LH):

    What a great opportunity to draft a very long post in response on a very nice day in the midst of a COVID19 pandemic, where I really can't go anywhere! Thank you! (Apologies to the REST of the Forum!)

    I'm glad you have a compact 2M amateur radio antenna design that you are happy with. But, no, I'm not personally interested in it in a professional or investment sort of way. Is it snake oil? I don't know. Could be. Lots of snake oil out there. Your description does not have nearly enough information to decide, nor will more posts on the topic help. It would take real work and my own tests for me to find out.

    Do you REALLY need my approval and interest? If so, read on. If not STOP HERE.

    Also ... your explanation is a little ... inconsistent. Going from HF to 2M is scaling DOWN, not up. All antennas are a blend of capacitance, inductance and resistance. And the electrostatic (capacitive) and magnetic (inductive) fields have to merge to form an EM field. So your antenna MAY emphasize some electrostatic aspect - but you throw out that term ("capacitive") as a mighty symbol. And don't explain why. Not enough info. Do I believe that a one inch long 2M antenna is narrow-band and "works"? Yes. Of course it works and has already been done, many times. And the more compact the antenna is, the more narrow-band it tends to be. Do I believe it's more efficient than a half-wave dipole (etc.)? I'm sure it can APPEAR to be, in the near field due to coupling phenomena or in the far field due to orthogonal directionality of some sort. But is it REALLY a 1-inch antenna with a revolutionary design that is more efficient under all conditions than a full sized one. Doubtful. But never "Impossible".

    Based on your claims, it WOULD be fun to play with, though. As an amateur. But if you want to go further...

    I've helped design, build and place in commercial service phased array antennas with many thousands of beams that others had said were impossible or impractical. Those antennas are now serving you and the community without you ever being aware of them, in applications far beyond what I once thought probable. And are bringing in a great deal of revenue in the process. So I understand what it's like to be belittled over a concept - then actually bring that concept to profitable life while under a great deal of opposition.

    Pay attention to that last part - it's very important. Revenue. Value. Profit. I learned the hard way that practical application and the harsh judgement of the business world is the crucible that separates interesting phenomena, dreams and ...snake oil... from useful inventions. You'll find a lot of perpetual motion "generators" on YouTube. But none, in actual revenue bearing application.

    Since I first retired, I've been asked to consult on many things. One of those was evaluating high-risk inventions proposed to a group of investors looking for high leverage payoffs. It was a fun thing to do for a while, but very repetitive. Lots of investment capital available this way. And lots of fraud. I found three general types of "inventors":

    1. Sincere persons (or groups of people) who had an idea that "MUST!" be valuable, only they had no idea how to apply it in a practical way. Often that idea was new only to them and frequently created problems far larger than the ones solved. Usually, they could NOT demonstrate the inventions and had only vague drawings of what it might look like. (Hey, nothing ventured, nothing gained!)

    2. The second group were inventors or groups of inventors who would propose, and often "demonstrate" new inventions, including "proof of concept" devices. But these devices were often existing commercial products cloaked under a disguising case or stand or drop-cloth or (you name it) and even possibly attested to by a group of sometimes vague individuals. The inventions did nothing new, or appeared to work under their "laboratory conditions" but either failed to work or (mysteriously) could not be duplicated outside of the laboratory. In every case, the game was to get as much funding from the investors as possible, for as long as possible, then walk away. And do it again with a different investment group. Background checks (not the simple, on-line style) showed in several cases that these individuals and groups were well organized and had been doing this for some time, making a decent living at it. Some even had their own very effective legal team to clean up afterwards. Have you ever seen the classic movie, "The Sting". Think of it as a variant of the "Long Con". "Psycho-Acoustic" musical healing devices and even invisibility gadgets are examples of this genre.

    3. The third group were the sincere, real inventors. Some had made inventing and selling off the resulting business basis or demonstrating the device idea and selling it off a lifelong and (usually modest) profession. They were capable, sincere, very bright and often very hard to distinguish from Group 2 above, initially. It took a while. Some inventions were web businesses, others were 3D TV concepts. Some worked out, some did not. All took capital to explore. And needed the investors to provide it - and access to influential people to improve marketing. Think "Shark Tank".

    In the end, the value of all of the inventions was decided by the market - the end customers. It really didn't even seem to matter if they were brilliant - or a "Pet Rock". But the fraudulent ones rarely made it (at least - not in my DIRECT experience). So... which category do you and your miniature 2M antenna fit into?

    Find an investor, develop the concept, market and sell the product. Your customers will be the eventual judges. Do you have the commitment and belief in your own invention to "Go the distance"? It's really up to YOU. Not me.

    And me? I just like to "Play with stuff" when I'm not over-employed, according to my XYL. I'll TRY just about ANY technical gizmo. As above - my opinion... is just an opinion. Everybody has one. And we're free to express them.

    Best Regards,

    Brian - K6BRN
     
    Last edited: Jul 19, 2020
  7. KE4LH

    KE4LH Ham Member QRZ Page

    :) Brian, I appreciate that.... Not necessarily looking for money or investments. I do have a patentable version but like you indicated, the business world can be quite cruel... And I've read of others who have patents and didn't make enough to pay for the patent itself. Have a friend who has 5 of them, cheapest one cost $5,000, others $10,000+. That's one of the reasons I've never tried to get one. I'm not sure it would ever pay for itself, no matter how well it worked.

    Scaled up refers to frequency (in my mind), not physical size but its just a few words. (semantics) I've been self employed for more than 30 yrs and have seen a lot of things come and go.

    The 2 meter version I refer to was outside of the near field, and tested on the same mount, same coax, same distance/location as the reference ground plane antenna. However, I have not tried to sell them because they are Extremely hard to get on frequency. The gain figure of 2dbd we observed was ~2.5 mhz wide. If you would like to build one or have me send you one to play with I can arrange that. But what I have built in the past are 40 meter (mostly) antennas that are 2 feet long and 2 inches in diameter and the performance is impressive. And if the scaling factor is anywhere near correct then perhaps that little antenna on 40 may have some gain....
    And I would imagine this design is closer to your "Pet Rock" in the market, and as you have said, makes the final call. Amazing to me that such a unique product/idea is simply cast aside due to a lack of knowledge... "The human condition" is correct. But I will try one last time to stir some interest and perhaps give away the software I wrote as a design aid just to see if there is enough interest for something new.....
    Anyway, I'll stop posting here about this. I just spent the last couple of hours looking thru the forums to see if I would be repeating a thread on this subject. And I'll see if I can't get one started.
    Hope you have a great day all,
    Tom Ke4LH
     
  8. K6BRN

    K6BRN XML Subscriber QRZ Page

    Tom (KE4LH):

    Nothing would really stop you from filing as an LLC and offering your antenna designs to the public, as Danny Horvat has done. with the EFHW antennas. You could have some fun, make a few bucks (not a LOT of profit in amateur radio), benefit the community and possibly evolve and improve the product. You could certainly "prove" that the antenna design approach is both practical and beneficial. Patent or not.

    Perhaps you don't need a patent to feel vindicated, afer all.

    On patents - Patents are expensive and take years to negotiate and receive. The best deal, in my experience, is to have a backer that is willing to pay for the patent and has a need or application for the invention. Then work out an equitable profit sharing arrangement - and not be too greedy. Once you have a producing patent, file DIV patents on it expanding on the idea and it's application. Because if you don't, others will. Generally any new (and "non-obvious") idea is a candidate for patent approval. Or an old idea used in a new way.

    Large companies generally divide patents into three categories: Dormant, defensive and producing. Dormancy generally means the patent has not been useful and the rights will be sold or dropped rather than renewed. Defensive means that the patents sre held against infringement claims by other companies in other areas - you sue me, I'll sue you. For a snapshot of that process gone terribly wrong, refer to the Apple vs. Samsung IP dispute of a few years ago. Producing patents are the most rare and this means that the patent either secures a critical market segment for the holding company, or is licensed to bring in revenue or is sold with residual use rights for a lump sum. Or any combination.

    Nice thing is that even if you are in inventor working for a very large company, you likely will be able to receive "due compensation" far beyond the well-known "Patent Award Bonus", IF (and only IF) that patent brings in a GREAT deal of revenue. In that case, many companies have somewhat hidden processes to further compensate employees. But sometimes these are ONLY offered if you know and ask about them and some fairly well hidden conditions are met.

    Best Regards, (and good luck!)

    Brian - K6BRN
     
  9. 2E0VSS

    2E0VSS Ham Member QRZ Page

    The original XFMR design was from PA0EJH
    Id be careful assuming it was Dannys design.

    M
    73
     
  10. K6BRN

    K6BRN XML Subscriber QRZ Page

    Hi Mark:

    I have confidence that the execution/productization of the MyAntennas EFHW antennas are strictly Danny's. His implementations are now being widely copied - but when I first looked around for similar products years ago (there are usually many in hamdom) or obvious writings on them, they were almost non-existent (I DID find a stub tuned variant which turned out to be a lousy design). The ARRL certainly seemed to be unaware of them. Perhaps I missed some obscure reference back then - not important, as Danny changed the market with his successful and popular designs.

    Now, is the basic electrical transformer concept his? Or the band alignment coil in the wire? Probably not. We all stand on the shoulders of those who came before us. That's reality. But Danny took all of the concepts, put them together with an excellent electrical and product design and reasonable price to become one of the easiest, most flexible and reasonably priced antennas on the market. Are they the best possible antenna? No, if such a thing exists. But for many hams, especially new ones, they're terrific. And terrific works just fine for most of us.

    So... on another topic, I really DO think that Nikola Tesla invented the polyphase electrical system concept, including the 1st practical, brushless electrical motor design.

    Any doubters? :)

    On that note - I'd like to also recommend a fine piece of historical fiction by Graham Moore called "The Last Days of Night" concerning the AC vs. DC current wars in the USA at the turn of the 20th century. I love history, and this novel is well researched and written with an in depth listing of historical facts and deviations used by the author in the book. He also provides a list of other reference materials I intend to explore. If you like to read, if you like history, and technical/engineering history in particular, this is a great book.

    Graham Moore was also the author of "The Imitation Game", about Alan Turing and his Bletchley Park codebreakers during WWII. Moore's book was turned into a major and popular movie in 2014.

    Wishing you all the best!

    Brian - K6BRN
     

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