Big Loops. What is the point of diminishing returns?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by K0MBT, Nov 30, 2018.

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  1. W1VT

    W1VT Ham Member QRZ Page

    A Rhombic is more than just a big loop. The idea is to align the lobes from each straight wire element for maximum gain.
     
  2. WB5WPA

    WB5WPA Ham Member QRZ Page

    I think the previous post asked "Can you say ..."

    Make a 'loop' big enough (multi wavelength), you start to get "traveling wave" effects whether: (1) you know it or not, (2) whether you like it or not.

    Terminate a large enough loop on the far end, you essentially get the Rhombic (unidirectional xmit and rx) effect. Perhaps not optimized, but the physics are at work there ...
     
  3. W1VT

    W1VT Ham Member QRZ Page

  4. W1VT

    W1VT Ham Member QRZ Page

    How big does a loop have to be to beat a 50 ft high Extended Double Zepp on 20M? 9.9 dBi gain at 20 degrees after subtracting the loss of an 8' 600 ohm matching section to a nominal 50 ohm impedance.
     
  5. WB5WPA

    WB5WPA Ham Member QRZ Page

    That's an unfair question. The Extended Double Zepp is (the active antenna elements are) 'phased' properly for directed gain.
     
  6. W1VT

    W1VT Ham Member QRZ Page

    But DXing is unfair! I use a pair of EDZs on 10 meters and a dipole. If conditions get good again on 10M I plan to put up a four element collinear, two high and two across to work Asia!
     
  7. W1VT

    W1VT Ham Member QRZ Page

  8. K0UO

    K0UO Subscriber QRZ Page

    K6LPM likes this.
  9. K0MBT

    K0MBT Ham Member QRZ Page

    Tell me that Dxing is unfair. I do it on 10 watts
     
  10. WB5WPA

    WB5WPA Ham Member QRZ Page

    Can you do it on 160? Have you given that a shot?
     

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