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EFHW and TGXL

Mike-VA3MW
Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

The end fed half wave antenna is a pretty common antenna replacing the G5RV for the I-need-one-antenna-to-do-all-solution.

However, it, like most similar is a compromise antenna. As quoted by VU2NSB:

the EFHW antenna is an easy-to-deploy antenna and therefore tends to be a convenient choice for temporary or field-day deployments, however, avoid making it your antenna of choice for permanent home installation. If you have other viable antenna options with a balanced feed-point arrangement that could equally well fit into your real-estate limitations, then go for it instead of the EFHW antenna... Even if your choice means that you might be able to cover fewer bands on a single wire, it might be worth it.

It is very possible to **** such an antenna sort of have it work well, but not great. It is also possible to have SWR/Antenna values that have complex impedances that can't be tuned out by the radio and even the TGXL.

This is well worth the read if you use an EFHW antenna today:



Comments

  • Ignacy
    Ignacy Member ✭✭

    I compared EFHW to my other dipoles or OCF. EFHW was always down. Partly thsi is due to a feeding point being low. Elevating the feed point helps.

    A big problem with EFHW is easy saturating (fast increase of SWR) once the core has overheated once. The solution is to get a beefer model.

    Ignacy NO9E

  • JasonSt
    JasonSt Member
    This was great, Mike. Perfect for a newbie like me.

    73 Jason KD9ZHF
  • VE7ATJ_Don
    VE7ATJ_Don Member ✭✭✭

    Another option for a 'do-it-all' HF antenna which I recommend (having done it twice in different locations) is a 43 foot vertical antenna with a 4 to 1 UN-UN at the base and lots of ground radials. My vertical is ground mounted and will load up fine with the Flex 6xxx built-in tuner on 160 thru 6m.

    It's not GREAT, but it works. Just my $0.02

  • K1UO Larry
    K1UO Larry Member ✭✭✭
    edited February 3

    and if you want the 43ft vertical to perform more efficiently on 160 and 80 just add the little known MFJ-2904 coil option for 43ft verticals.

  • WX7Y
    WX7Y Member ✭✭✭
    edited February 4

    In theory the End Fed Antenna is NOTHING more or Less than a J Pole or ZEP antenna if constructed right, and Mikes posted a great article which I have found to be very accurate as you go up in frequency and get more multiples of the 1/2 Wave antenna.

    If your EFHW is Saturating the transformer then you must have a way under rated Transformer, I build my own and I can run ALL day long with out over heating and saturation @ 1.2KW on FT8 or easily run Full legal power on SSB from 80 to 6 Meters at <4:1 except for 12 Meters and 30 Meters all day so they work well with my TGXL Tuner and the Tuner in the Radio.

    I build my own transformers, I figure that each toroid is good for 500 Watts Intermittent duty cycle so I use 4 stacked 2.25" or 3 stacked 3" Mix 43 toroid's for 80M and up and Mix 31 for 40 Meters and below if your building a EFHW for 160M.

    I just have not ever seen MY Transformers saturate and as you have said get the feed point up in the air and it will work a bit better than being at ground level, but I do have one that is Feed just 6" above the ground using the ground rod as the anchor and it works fine in a inverted L format, it is a bit noisy because of the vertical part of the End Fed but works just fine on the bands it is designed for.

    Don't waist your money on the Store bought Transformers that THEY rate for 1.5KW, there really not hard to build correctly with room to spare for a much lower cost and have a MUCH longer radiator.

    I can't imagine how a 43' radiator can compete with a 128' Radiator at 80 Meters but that is just my opinion.

  • frc2302
    frc2302 Member ✭✭

    Just found this thread, and thank you - good info.

    I have a 5-band parallel loaded dipole that's resonant and pretty effective on those bands, but due to the coils, isn't useful on the whole 80m band. I am considering whether to add temporary pigtails to it for the upper end, or just throw up some other wire. I think I may just add another parallel wire, even though it'll have to droop at the ends.

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