End Fed antennas Vertical polarisation?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by OG6Z, Oct 13, 2021.

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  1. OG6Z

    OG6Z Ham Member QRZ Page

    Hi Om's need to ask you following
    Im using a Hyendfed antenna which the total length is approx 23m/77ft might be wrong
    My question is has anyone tried an endfed vertical mounting?
    I know the inverted L antenna have tried and it words quite good locally in Europe.

    Im intrested of what will happen if I mounted it as an ordinary L shape ?

    That would meen that I have approx 6m/ 20ft horizontal line from feeding point and after that the rest of the antenna straight vertical. (Can't get it high enough to set whole antenna totally vertical... )

    Has anyone tested this? and if you know the radiation patterns what happens to them I would be very happy if you can share it with me.

    I tested it my self and could hear stations from all over the Europe on 80m .. is it vertical radion which gives it ???

    The local stations were of course a bit but not much weaker than in inverted L compared it also with my loopskywire .. and ... yes should not .. my loop skywire outperforms the endfed on every band .. but maybe long distance to south and central Europe on 80m band it's quite similar not sure.. anyway..

    Thinking also that maybe I should bypass the unun 49:1 balun and ad counterpoises?
    Or maybe just ad counterpoises direct to the unun 49:1 balun since there is a possibility to that. ?

    Happy to receive more information and thoughts from hams with more experience than me. 73 s de Marko OG6Z
     
  2. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    Yes, others have hung them as Inverted L antennas, as well as vertically. They will have vertical polarization.
     
  3. W9YW

    W9YW Premium Subscriber Volunteer Moderator QRZ Page

    Keep the bottom of the L above ground a few feet; more is better. Remember also that you need at least 20M/60' of coax to serve as a counterpoise on a 49:1 EFHW, as it's a Voltage/Hertzian antenna. 30M/100' is even better, but more length will start to cause realistic insertion loss.

    Some operators also add 4 to 5M of a short length of coax to the 49:1, and insert a current balun at that juncture, to keep the RF on the antenna. I haven't tried that yet.

    My EFHW is a sloper, and I have worked the planet. OK, most of it. OK, not enough ASIA.

    73 Tom W9YW
     
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    First, the correct length for a 40m/20m/15m/10m EFHW is developed in this previous post:
    https://forums.qrz.com/index.php?th...a-kit-and-doing-it-cheaper-and-better.770104/

    The discusses the reasons for putting a CM choke on the coax:
    https://forums.qrz.com/index.php?threads/core-for-efhw-1-49-transformer.677495/page-5#post-5954521

    This is specific to running a vertical or inverted-L EFHW ground-referenced by connecting the transformer common terminal (where the coax shield connects) to earth ground using a single ground rod (not radials):
    https://forums.qrz.com/index.php?threads/efhw-vertical-patterns.756180/#post-5805631 and
    https://forums.qrz.com/index.php?threads/efhw-vertical-patterns.756180/#post-5805750
    https://forums.qrz.com/index.php?threads/efhw-vertical-patterns.756180/#post-5806568
    Those three posts make the case that if all you have is a single ground rod, the antenna feedpoint impedance should be high (i.e. voltage fed, very close to a multiple of a halfwave).

    On any frequency where the feedpoint impedance is low (current fed, not close to an integer multiple of a halfwave), the losses are huge, even though the tune-up is easy for the tuner. The loss is in the dirt surrounding the ground rod, not in the tuner or feedline.
     
  5. W9XMT

    W9XMT Ham Member QRZ Page

    Below is the result of a computer study of this type of installation. The lengths of the horizontal and vertical wires of the "L" (arbitrarily) were adjusted to accommodate a 3m clearance above the Earth for the horizontal wire, for personnel safety.
     
  6. W9XMT

    W9XMT Ham Member QRZ Page

    Here is the graphic mentioned in Reply 5 (I wanted to edit some of the text).

    [​IMG]
     
  7. N4UFO

    N4UFO Ham Member QRZ Page

    I have an EFHW inverted 'L' up now for 160m, also resonant on 80, 60 & 40m. Feedpoint is mounted about a foot & a half above ground, have a 95 foot long feedline slightly buried with a choke just before entering the house. Pics and some explanation are on my QRZ page.
     

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