Dipole Vs EndFed - Field Measurements

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  • Опубліковано 25 гру 2024

КОМЕНТАРІ • 30

  • @StreakyP
    @StreakyP 2 дні тому +4

    This is a beautifully thought out & conducted trial. Respect.
    Just some thoughts:-the efhw has the advantage of working on even & odd harmonics but the dipole cannot handle even harmonic operation however balanced antennas like the dipole can suffer less from local electric noise pick-up compared to unbal antennas like efhw & verticals. It looked like your test site was well away from local noise sources so here given its equal performance to the dipole but advantage of even harmonic operation for the efhw I'd probably choose the efhw, but in an urban environment for the home station I'd possibly choose the dipole instead IF it was quieter.
    The fact you were measuring snr was nice to see. It would be interesting to see the same trial conducted in a noisy urban environment to see if the theoretically quieter operation of balanced antennas gave the dipole any advantage there.

    • @CrazyChekov
      @CrazyChekov  2 дні тому +1

      thx for the comment! Great points!

  • @wojteksz.8984
    @wojteksz.8984 День тому +1

    This video does not state whether a dipole or EFHW is better; instead, it shows which of the antennas in the author's specific setup and configuration provides a stronger signal.
    It cannot be said that the measurement is wrong, but it certainly does not answer the question: "Dipole or EFHW - which is better?"
    We could try addressing the following questions first:
    Was the layout of the coaxial cable considered, and its interaction with one of the antenna's arms, where it might run parallel?
    Was the efficiency of the 1:49 transformer considered, and were the dB losses subtracted from the result?
    (What would the result be if the EFHW were powered in parallel through an LC resonance circuit? Resonance circuits have very high efficiency but make the antenna single-band or require retuning.)
    Did the author consider that when using a dipole, the EFHW antenna has no break in the center and acts as a half-wave element that could behave like a parasitic element?
    What constituted the counterpoise for the EFHW, and how was it implemented? (Coaxial cable, grounding, or a wire segment?)
    Was it taken into account that the effectiveness of the choke depends on where it is installed along the coaxial cable? The impedance for common-mode currents changes along the coaxial cable.
    These are just a few example questions.
    As we can see, the video does not conclude whether the dipole, as a dipole, is better than the EFHW, as an EFHW. The video only shows that the author's dipole is better in his setup, considering the antenna suspension configuration and the coaxial cable layout.
    Nevertheless, it is worth noting the remarkable measurement method, where our own station automatically responds and provides a report.
    Choosing the frequency 7078 kHz was a good decision, as it avoided distortions in the reception report in dB caused by interference from other stations.

    • @CrazyChekov
      @CrazyChekov  17 годин тому

      thx for the detailed comment. especially the coax coming down the pole from the dipole bothered me a bit too. it wasnt really parallel but for sure that could be improved for future tests. good points!

  • @DaDitDa
    @DaDitDa 2 дні тому +5

    Proof that a dipole is a dipole, regardless of how it's fed...

    • @rogerlafrance6355
      @rogerlafrance6355 2 дні тому

      Yes, but used as a multiband antenna, multi lobes increase with higher bands. Trading some performance for multiband works in most cases. It seems to me that performance drops above two bands. Upgrades include Traps and Relays to switch wires

  • @HowardKlein1958
    @HowardKlein1958 3 дні тому +1

    I've found end fed half wave works very well, especially low to ground NVIS propagation.

    • @CrazyChekov
      @CrazyChekov  2 дні тому

      @@HowardKlein1958 Yes, I thought the difference to a center fed dipole would be bigger. these transformers seem to work very well.

  • @chrissuddell7940
    @chrissuddell7940 День тому +1

    Well done.

  • @kenmartin1211
    @kenmartin1211 17 годин тому

    Nice test ! Thank You

  • @skypilot0077
    @skypilot0077 День тому +1

    An end fed is a dipole. It's just fed at the end instead of the center. Deployed as a flat top, sloper or inverted V they should perform the same.

    • @chrisolson968
      @chrisolson968 День тому

      Skypilot, you are flying too high. A dipole is the best antenna in a inverted v fashion. In an efhw. The matching transformer does the heavy lifting to make the antenna radiate efficiently. With a dipole although a mono banded antenna, is the most efficient. However, this gentleman made a great matching transformer, due to the efhw performance. I am impressed with the results. However you cannot beat a balanced dipole. You just cant. Yes they are both wire antennas. A dipole is a dipole. An end fed is an end fed.

  • @M7XCB
    @M7XCB 2 дні тому

    Very interesting video.

  • @wojteksz.8984
    @wojteksz.8984 День тому

    It is unclear whether the statement "WINNER" refers to the dipole relative to the EFHW or to the dipole with a choke versus without a choke when using a voltage balun.
    The statement "WINNER" about the dipole, where the assumption from the video title suggests it is in comparison to the EFHW, could be misleading for new radio amateurs.
    Even though a more accurate phrase like "MY DIPOLE IS THE WINNER" would be appropriate, the use of "WINNER" is somewhat inadequate. Nonetheless, I give a thumb up 👍for the effort, as it provides inspiration for others.
    73, Joe

  • @hennero.3826
    @hennero.3826 5 днів тому +1

    Thanks for sharing this! 🙂
    This is exactly the information that I am interested in most as I am forced to operate outdoors when I really want to do interesting DX (due to my living situation), so I am looking for the most efficient wire antenna for outdoor operation. By the way as of now with being into the hobby a few months only, I am trying to go for verical wire antennas which is feasible as I am using most 15/17/20 m.
    And as you mentioned - I would have expected the advantage of the dipole to be a bit more obvious.
    73 de DL1HNR

    • @CrazyChekov
      @CrazyChekov  4 дні тому +1

      thx a lot!
      Yes for DX and 15-20m I would also chose a vertical antenna.
      73!

    • @hennero.3826
      @hennero.3826 4 дні тому

      @@CrazyChekov Until now, I was not really sure if this approach makes sense as it is merely what I as a newbie understood so far from radiation patterns and everything that goes with it, so it is good to see that you confirm my conclusion to go for a vertical for that purpose! This help me, thank you.🙂

    • @RoelandJansen
      @RoelandJansen 3 дні тому

      ​@@CrazyChekovI did, actually

  • @P.SeanCoady
    @P.SeanCoady 2 дні тому

    I am surprised as well

  • @user-yh7mv7jd1l
    @user-yh7mv7jd1l 2 дні тому +1

    Thank you. I appreciate the methodology and the data. It’s very illustrative. KO6DEV

  • @huangcheng2130
    @huangcheng2130 3 дні тому +1

    The directivity of end-fed antenna is very strong, so it is meaningless to pay attention to directivity when comparing horizontal antennas.

    • @sfrahm1
      @sfrahm1 3 дні тому

      "The directivity of end-fed antenna is very strong" In what direction? How is it different from a dipole arranged in the very same configuration? My understanding is that it is nearly exactly the same.
      It is the shape and placement that primarily determine directional or elevation characteristics. If the current node(s) is/are at a significant height relative to wavelength, the angle of radiation will be low and visa versa for low heights and NVIS radiation.

    • @CrazyChekov
      @CrazyChekov  3 дні тому

      better to have it equal for both antennas in a comparison imo. removing one variable from the test.

    • @gunterkonig959
      @gunterkonig959 День тому

      You are right, because the efhw antenna field pattern is for a small part directed in the opposit to the feed point.

  • @mrlowbudget6979
    @mrlowbudget6979 Годину тому

    Oha wiener Dialekt in Englisch ist aber schwierig :-)

  • @vladtepes481
    @vladtepes481 15 годин тому

    While your experiment is rather good but there are flaws. The radiation pattern of an end-fed and center fed dipole are identical for a fixed antenna height. The chief difference will be the efficiency of the 49:1 UNUN. A center fed dipole is rather efficient. Your antennas are placed 90 degrees with respect to each other so the signal received at a distant point be different. Antenna modeling can be used to determine the effect of antenna orientation. You only need to model a centerfed dipole as the radiation pattern is unaffected by the feed point location. You just need to know the difference in gain for a change of 90 degrees. A low inverted V will not have much directionality but modeling is easy using EZNEC or MMANA-gal.

    • @CrazyChekov
      @CrazyChekov  52 хвилини тому

      thx for the comment. I wouldnt call it an experiment. Its was just a test.
      I like to test stuff more in the real world than modeling it. The direction of the targeted station was between the dipole and the endfed. 45deg to each of them.