The j-pole antenna is fixed...

Discussion in 'Amateur Radio News' started by KX4O, Jul 9, 2020.

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  1. WD4HXG

    WD4HXG Ham Member QRZ Page

    AEA did it with the Isopole antenna they sold decades back.
  2. KE4IKY

    KE4IKY Ham Member QRZ Page

    Although I think a more accurate description would be in the
    23rd edition of the ARRL antenna book. Figures 16-11. where the mast IS the feedline.

    It's a little confusing the way the antenna book (and hams in general) describe things as "impedance transformation" which is a very non-visual way of describing what is happening.

    Sometimes hams have a funny way of viewing and stating things,

    /Rant on
    like a portable radio being something that is transported in a vehicle, and a mobile radio being something that is hand carried. ;)
    /Rant off

    I was taught to visualize it as looking at a 1/4 wave stub that is shorted at its end, and drawing a sine wave along it, the short is where the zero crossing was, flowing back 1/4 of the sine wave shows an open being "forced" on the line.

    Figures 24-16, or 24-19, of the 23rd edition show more sophisticated uses of the 1/4 wave stub that are clearer than the RADAR references that I used earlier (mostly the same idea though).

  3. HK3VIO

    HK3VIO Ham Member QRZ Page

    Well, hello there to you all, I don´t know but I do still enjoy very much the antenna building stuff, as a matter of fact, my prefered scenario is the roof from let´s say 8 am! ;D And very much likely so, I´m gonna build me one of this decoupled J-pole. just for the fun of it, but of course I won´t tell anyone! 73´s
    KX4O likes this.
  4. KX4O

    KX4O Ham Member QRZ Page

    The patents are for the US and its territories only. Have at it and let us know how it goes.
  5. KX4O

    KX4O Ham Member QRZ Page

    That's one of the primary points of the patent... to document, permanently, the issues along with a novel solution to those problems, hence reinforcing the problems really do exist. This is documented in a system that makes the resulting research available to the public rather than buried behind the paywall of the IEEE or equiv.
    Who didn't research it? Me?
    Perhaps so and I welcome evidence that the combination of techniques presented in the patent preexists the patent. I looked hard, documented references aplenty in the two patents (unusual for patenting), and found no published solution matching the claims. Make no mistake though... the burden of proof no longer rests with me after issuance of the patents. So please... back up your assertions with hard preexisting published evidence.
    Because I work in antenna engineering in a gov. lab has little to do with anything.

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