1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

The Truth, ... ,and Nothing But The Truth (as I've experienced it)

Discussion in 'Amateur Radio Antennas' started by HomerBB, Jun 29, 2021.

  1. HomerBB

    HomerBB Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    3,785
    Likes Received:
    2,180
    I have tried numerous EFHW 49:1 antennas, and no matter how good they look with a resistor load I have never had one successfully load with a wire across multiple bands with >2:1 SWR on all the bands. I've always had to use a tuner somewhere. In fact, running a ~66' wire in the inverted V configuration for field day in order to avoid a tuner here are the transformers I had to use to get >1.7:1 SWR on all these bands (including 11m).
    Band-----X-former
    160m--------49:1
    80m------------9:1
    40m----------49:1
    20m-----------49:1
    17m-------------9:1
    15m-----------49:1
    12m-------------9:1
    11m--------------4:1
    10m-------------49:1

    Sometimes a 16:1 transformer would work, but all those have listed worked to a lower SWR by a little.



    I have tried different length resonant (?) wires. And, nope. Some say they've done it, but it eludes me.
     
    #1 HomerBB, Jun 29, 2021
    Last edited: Jun 29, 2021
    Crawdad and Slowmover like this.

  2. Slowmover

    Slowmover Elmer

    Joined:
    Feb 17, 2015
    Messages:
    5,270
    Likes Received:
    8,281
    Nilotic Greek translation is the successful path.
     
    Crawdad likes this.
  3. HomerBB

    HomerBB Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    3,785
    Likes Received:
    2,180
    My Greek sucks.
     
    Crawdad and Slowmover like this.
  4. tecnicoloco

    tecnicoloco Tweaknician in Training

    Joined:
    Apr 23, 2005
    Messages:
    579
    Likes Received:
    306
    But the Antenna MacGyver never give up until Victory is achieved (y)
     
    HomerBB, Slowmover and Crawdad like this.
  5. Captain Kilowatt

    Captain Kilowatt Professional Amateur
    Staff Member

    Joined:
    Apr 6, 2005
    Messages:
    16,632
    Likes Received:
    10,455
    A 49:1 works on all the bands except the WARC and of course 11m bands. You show that in your chart above. The anomaly in your case is 80m. I have an EFHW and the SWR is acceptable on all the bands with the exception of the WARC bands which is to be expected since the harmonic relationship is different. Many people use an inductor placed at the near end to make things level out on the higher bands. IIRC they call it a "compensator". I am surprised you were able to use a 49:1 on 160m and be acceptable considering it is only 1/8 wave on that band. Mine is about 135 feet long and is in an inverted L configuration.
     
    Slowmover and NZ8N like this.
  6. Jay Mojave

    Jay Mojave Sr. Member

    Joined:
    Nov 17, 2015
    Messages:
    284
    Likes Received:
    508
    Hello All: Yeah Great question there Homer, had a few long wire antennas and was only impressed with the dipole cut for a band. So what is the all band long wire or dipole HF gettem all wire antenna. I see many with home made tuners and Dyno Labeled makings on the front panel makings for the different bands. Mabey no way out but to use a tuner.

    Jay in the Great Mojave Desert
     
    HomerBB and Slowmover like this.
  7. Justme

    Justme Sr. Member

    Joined:
    Jan 28, 2008
    Messages:
    564
    Likes Received:
    663
    Only company i trust with endfed antenna's is HyEndFed 8 Band 1KW AL Plaat (hyendcompany.nl)
    80 to 10 no 160 beccause a half wave on 160 woud be 80 meters long.....
    Fact you will need tuner on one or more bands if you want to tune a piece of wire on all the frequencies you are after.
    Even my Fritzel FD-4 with coil for 160 meters will need some tuner help on some bands, not much, but still.
    My 77 feet vertical uses the MFJ998 legal limit tuner working from 160 to 10, that says nothing about efficiency and radiation pattern, but it will tune it flat.
    I don't use thaat vertical above 20 meter there is the Imax 2 K for doing fine there, worked all continents with both antenna's.
     
    HomerBB and Slowmover like this.
  8. HomerBB

    HomerBB Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    3,785
    Likes Received:
    2,180
    CK, your explanation rings truer than any of the hype/ads I have seen about the 49:1 EFHW.
    I do have the little compensation coil for the upper bands inline on the wire. At home my Imax2k does all the 15, 12, 11, and 10m work, but as a portable I was looking for the claimed all band wire. I guess I'll just carry more than one transformer out portable.
     
    Slowmover likes this.
  9. Captain Kilowatt

    Captain Kilowatt Professional Amateur
    Staff Member

    Joined:
    Apr 6, 2005
    Messages:
    16,632
    Likes Received:
    10,455
    The most reliable and competent maker of an EFHW I have experienced is.............myself. It was a LOT cheaper too! I made my own from a pair of stacked T240-52 toroid cores instead of the type 43. Better performance up to 6m. 20200825_132722.jpg 20200831_151707.jpg
     
    #9 Captain Kilowatt, Jun 30, 2021
    Last edited: Jun 30, 2021
    ForestRunner98, Crawdad and HomerBB like this.
  10. Captain Kilowatt

    Captain Kilowatt Professional Amateur
    Staff Member

    Joined:
    Apr 6, 2005
    Messages:
    16,632
    Likes Received:
    10,455
    Here are the results before a bit of tweaking the 10m band which also lowered 15m a bit. At the time 10m was dead so I was not too concerned with it. I have a Hustler 5BTV as well.It is common practice to use an EFHW cut for 80m on 160m by installing a relay at the feedpoint to bypass the transformer thereby making the antenna wire a simple quarterwave on 160m which is what I have done after these were taken. Match is good around 1870 KHz. 20200831_150545.jpg 20200831_150514.jpg 20200831_150443.jpg 20200831_150328.jpg 20200831_150354.jpg 20200831_150417.jpg
     
    #10 Captain Kilowatt, Jun 30, 2021
    Last edited: Jun 30, 2021
    Crawdad and HomerBB like this.
  11. NightThumper

    NightThumper Sr. Member

    Joined:
    Nov 8, 2017
    Messages:
    536
    Likes Received:
    1,216
    Captain, those are some nice numbers!
     
  12. HomerBB

    HomerBB Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    3,785
    Likes Received:
    2,180
    And there is my same experience.
    I am a no code General ham, so the "best" matches seem to fall too low, into the Extra portion (guess I need to fix that part). Adjust the wire length to get them up on the bands, and they go awry. And, my Icom 746 starts rolling back power when the SWR goes above 1.3:1 - annoying. Those 2.2 and 3.1 SWR numbers mean I must use a tuner.
    I find I do just as well with a non-resonant wire and a 9:1.
    BTW, CK, you're setup is really slick.
    I wish they didn't want a significant portion of my retirement for 52 toroids. About 3x to 4x the price of 43 mix.
     
    #12 HomerBB, Jun 30, 2021
    Last edited: Jun 30, 2021
    Crawdad likes this.
  13. Captain Kilowatt

    Captain Kilowatt Professional Amateur
    Staff Member

    Joined:
    Apr 6, 2005
    Messages:
    16,632
    Likes Received:
    10,455
    Or wind your own transformer with taps and select whichever tap provides the best match.
     
  14. TheBlaster

    TheBlaster Well-Known Member

    Joined:
    Jun 29, 2020
    Messages:
    227
    Likes Received:
    254
    I use a 20m EFHW although it is mono band cut for 20m. I had a 64:1 version but it was a little underrated. I can get 1.2:1 which puts me in a happy place...(but not for power handling of 100W PEP) I also have a 49:1 version and cannot currently get it below 1.5:1 - It does not seem to be a "trim or add wire situation" I have had it longer bent it over and ultimately cut it and still it won't go down. It now seems as good as it will get in the position it gets put up.

    Tried a 8 turn ferrite toroid coax choke in line just below the unun - the numbers charged slightly according to my internal radio meter but very marginally and became worse on other areas of the band.... not enough to even bother with the choke.

    So my hasty yet not ultimate conclusion is that a 64:1 may be a better solution than a 49:1 - I will continue to experiment.

    I mention this with my basic experiences and not much deep knowledge about the effectiveness of the 2 matches 49/64 : 1 matches and caveat I am using just approx 10m wire cut for one band. I would use 64:1 if/when I make one myself. I do use some small counterpoise wires as well (which given no useful change with the choke seem to do their job).

    49:1 seems to work ok but SWR on the 49:1 is not at that... "no longer in the back of mind" stage.

    Some of this must be feed point, vs wire length, vs surrounding objects and influence of ground below.

    It feels good when it is 1.2:1 - we all know that feeling.

    1.6:1 is in the "Oh well.. I suppose it'll have to do then." zone.
     
    #14 TheBlaster, Jun 30, 2021
    Last edited: Jun 30, 2021
    HomerBB likes this.
  15. magnuman

    magnuman Well-Known Member

    Joined:
    Feb 20, 2010
    Messages:
    210
    Likes Received:
    160
    Hi Homer,
    I have experimented with many EFHW set ups.
    As your radio starts shutting down at 1.3 swr it might not be the right radio to use with an EFHW. I use the EFHW so I don't need to use a tuner.
    If you just want one band then hook up the wire to the transformer and adjust the wire for the lowest SWR. If you are lucky it will also be close to resonance there too. If not raise the transformer a bit more and recheck. The position of the transformer seems to change the antenna properties a lot more than where you hang the other end! Although I see many pictures with the transformer a couple of meters off the ground I have found the antenna works better the higher you have the transformer. Mine is currently about 20ft up and the wire slopes up to 50ft from here.
    For best results I have found single band set as vertical as possible, (sloper good too). Just need the toroid transformer and cut the wire to suit.
    For single band tuned to close to 1:1 SWR there shouldn't be too much issue with CMC's on the coax but I think it is always a good thing to have a choke inline. To get the best match to 50 ohms the boffins reccommend placing the choke 1/20 of a wavelength in free space down the coax from the transformer. It does not seem to be a good idea to put the choke directly under the transformer. I use an 80 to 10m EFHW from Myantenna and I have the choke placed just under 4m from the transformer. Works well on all the bands it is supposed to. I do not use a counterpoise or earth at the transformer but I do have a station ground.
    Multiband use.
    It is very difficult to get one toroid to tune from 80 to 10m without some extra steps. For 160 and up to 40m you can use 3 winds on the primary and either 21 (49:1) or 24 (64:1) on the secondary.
    For 40m to 10 it should work well using 49:1 because the bands line up well.
    7.1mhz, 14.2mhz. (x2) 21.3 mhz (x3) and 28.4mh (x4)
    For some reason the higher bands want to go high so the inductor in the antenna wire 2m from the transformer certainly helps here as does the 100pf accross the primary.
    First thing is to set the choke on the coax for the lowest frequency (1/20 lamda as above) and trim wire length for the lowest swr on 40m. Then see where you stand on the other bands and with some fiddle farting around with the location of the transformer you should be able to get the other bands to play.
    Once we try to bring 80m into play we run into problems with the width of the 80m band. using our 40m reference of 7.1 if we halve that we have 3.55 mhz which is probably too low for most of use. I have been able to raise the 80m frequency to just under 3.7mhz at 1.6 to one While keeping the 40 to 10 intact by adding 500pf in series at the center of the antenna wire. I have the inductor 2m along the wire from the transformer and 100pf accross the primary of the toroid and the choke at about 3.75m down the coax. It works well on 80, 40, 20, 18,15, and 10. 60, 30, and 12 are no go without a tuner but as they are not half wave or multiple for the 80m wire length that is hardly surprising.
    An antenna analyzer is of enormous help here as is a decent amount of perseverence but I don't think you lack perserverence!
    You probably have it sorted by now.
    The 43 mix toroids are fine. Just use one while you are fiddling about and then once you get things lined up build a multicore transformer to handle the extra power.
    The advantage of being able to tune these to a very low SWR is the increase in bandwidth achieved.
    Good luck.
     
    HomerBB likes this.

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!