1/4 Vertical Question

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by K5WZI, Aug 11, 2018.

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  1. K5WZI

    K5WZI XML Subscriber QRZ Page

    Suppose the following

    1. Elevated 1/4 vertical insulated from ground
    2. Elevated radials spaced evenly about the base of the antenna and insulated from ground
    3. The sum of the currents in the radials is equal to the current in the vertical.

    Would this be considered a balanced antenna?
     
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I'd say "no," because only the vertical unipole radiates; the radials don't (or shouldn't). An elevated single radial will (it's an "L" antenna) but when you add multiple radials, there should be sufficient cancellation so the radiation is really vertically polarized.

    I think the sum of radial current will always be the same as the radiator current; ineffective radial systems that can't handle any current limit the amount of current the vertical element can accept.:) This is a reason why copper wire radials are more efficient than "earth."
     
    NH7RO likes this.
  3. K5WZI

    K5WZI XML Subscriber QRZ Page

    Thanks WIK for your reply. That was my gut feeling. Oh well, I thought it would be cool to feed
    such an antenna with open wire line and operate it on multiple frequencies.
     
  4. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    You could, using a good balanced tuner in the shack (as opposed to feeding with coax and a remote tuner, which is more expensive and complicated).

    Did you see the article in the August QST about letting open wire line -- well, he used "window line" which is almost as good -- lay on the ground (protected by slip-on foam insulation to keep it above the ground)? That was pretty cool. The article does describe using balanced line, laying on the ground and other stuff, to feed a vertical.
     
    NH7RO likes this.
  5. W7TFO

    W7TFO Subscriber QRZ Page

    Check out Don K4KYV, the owl/tower guru.

    73DG
     
  6. K5WZI

    K5WZI XML Subscriber QRZ Page

    Thanks you guys. I will check out your suggestions. Maybe there is hope!
     
  7. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Yeah, it may not be ideal and the 'balanced feed line' may not operate in a completely balanced mode but it can definitely work.

    I'm pretty sure Marconi didn't feed his verticals with coax....seeing as it hadn't been invented yet :)
     
    NH7RO likes this.
  8. NH7RO

    NH7RO Ham Member QRZ Page

    Of course not. Macaroni fed all of his antennas cheese, duh!
     
    NL7W and KU3X like this.
  9. AI3V

    AI3V Ham Member QRZ Page

    Electrically speaking, yes.

    Mechanically speaking no.

    With apologies to Tina Turner, What's feedline got to do with it ? :)

    Rege
     
    NH7RO and KU3X like this.
  10. NH7RO

    NH7RO Ham Member QRZ Page

    Thanks, Rege. That was a catchy song back in the 80s and it still is today. It'll be hard to get it out of my head now that you reminded us of it.
     

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