Topband: 4-square phasing

john battin jbattin at msn.com
Tue Dec 14 21:43:23 EST 2004


  ----- Original Message ----- 
  From: George & Marijke Guerin<mailto:gmguerin at voyager.net> 
  To: DAVID CUTHBERT<mailto:DAVIDNNAN at MSN.COM> ; topband at contesting.com<mailto:topband at contesting.com> 
  Sent: Tuesday, December 14, 2004 7:11 AM
  Subject: Re: Topband: 4-square phasing


  See comment below on phasing reversal with a BalUn or UnUn:
  ----- Original Message ----- 
  From: "DAVID CUTHBERT" <DAVIDNNAN at MSN.COM<mailto:DAVIDNNAN at MSN.COM>>
  To: <topband at contesting.com<mailto:topband at contesting.com>>
  Sent: Monday, December 13, 2004 11:28 PM
  Subject: Topband: 4-square phasing


  > Ron,
  >
  > if I have it figured correctly the 3/4 wavelength lines will cause the two 
  > extra elements to lag by 180 degrees. You can fix this by doing one of 
  > these:
  >
  > 1) adding 180 degrees of line to the two existing element feedlines
  > 2) adding 180 degrees of line to the two 270 deg lines to have 450 deg 
  > lines
  > 3) invert the phase of the two 270 deg lines with a choke balun (hot to 
  > shield/shield to hot)

  A regular balun or UnUn will also do the 180 degree reversal job:
  Top of first winding to 270 deg line center conductor, bottom to shield.
  Top of second winding to shield, bottom of second winding is reversed phase 
  coax center conductor connection.
  The transformer can go on either end of the line!

  George        K8GG

  >    Dave WX7G

  Please note that this will be a more narrow bandwidth approach than having equal 3/4 wave lines on each antenna because as you change frequency the phase shift of the feeds will not track each other. Why not just make them all 3/4 wave and be done with it??
  John K9DX


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