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20m Vertical dipole vs 20m 1/4 wave. When is a 1/4w better, if ever?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KE0EYJ, Dec 5, 2017.

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  1. AK5B

    AK5B Ham Member QRZ Page

    Roger that, Charles---no stinkin' coils! I suppose the matching unit in the middle of the TWA model is due to most of their antennas being multi-banded.

    I thought of your (our) VWMI Painter's Dipole earlier but it didn't occur to me that all we'd need to do is orient it sideways and adjust the lengths of the elements/cap hats---cool. I'll really have to cobble one together for 40 or 20 sometime and take it down to our beach (which looks almost the same as the one in the UK pic you posted earlier).

    73,

    Jeff
     
  2. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Gotcha on the no coils... but a 40m antenna is pretty darned big. I was assuming I wouldn't be able to pull it off without a coil, of some sort?

    If a person adds more to the cap hat, to compensate, does that add more losses? Or do cap hats not present much of any loss?
     
  3. AK5B

    AK5B Ham Member QRZ Page

    Cap hats are a method of loading and generally reduce ground loss in vertical configurations.

    Probably a good idea to tilt the bottom one up more like a flattened V when configured as a vert. dipole (or get it a bit higher above ground otherwise).
     
  4. KC8VWM

    KC8VWM Ham Member QRZ Page

    Last edited: Dec 6, 2017
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  5. AK5B

    AK5B Ham Member QRZ Page

    I'm already planning my Double T-Bar Ranch...

    Many thanks for the links and info!
     
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  6. KE0EYJ

    KE0EYJ Ham Member QRZ Page


    Now you've got me thinking about doing some kind of capped horizontal 40m dipole on the 10m wide portion of my roof, which is broadside to the USA. The problem is -- do I build it with the caps straight up and down, or perpendicular to the Earth?

    In which way does the H antenna radiate? IN-line with the caps, or perpendicular to the caps?

    In your horizontal dipole, you've got the cap ends level with the ground. In the H models above, they are different.
     
  7. N8CMQ

    N8CMQ XML Subscriber QRZ Page

    I would put the ca

    I would put the cage around his welding area...
     
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  8. AK5B

    AK5B Ham Member QRZ Page

    Of course they look different---but they are really the same type of antenna with different polarization. The ProAntenna/TWA double T-bars are capacitively loaded vertical dipoles; Charles's painterpole dipole (Painter'sDipoleTM) is a capacitively loaded horizontal dipole.

    The cap hats are generally made longer for the vertical dipoles to keep the vertical height manageable.

    In either case the cap hats will always be parallel to ground.
     
    Last edited: Dec 6, 2017
  9. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Ok, but am still confused which way the antennas are firing. I would assume Charles dipole fires broadsides, but what about the vertical dipole H?
     
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  10. AK5B

    AK5B Ham Member QRZ Page

    Vertical dipoles are omnidirectional; horizontal dipoles are bi-directional.
     
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