Topband: Out of phase verticals

Bob Kupps n6bk at
Mon Jun 3 05:27:10 EDT 2013

Hi I am installing an 8 way rx array and will be taking down the nearby unfinished xmit 4 square. I plan to relocate one of these tx verticals about 100m from the nearest rx element as an omni tx ant. After thinking about it I have room to put another one back up too, anywhere from about 130-160' apart in the direction of EU and VK/ZL from here, but maybe 10m closer to the rx array. On modeling, this array fed out of phase looked like I could get 3 dB tx gain in those directions, a 4 deg elevation angle drop plus the null would be facing the rx array (if it works that way in the near field). Since this is solely a tx ant it looks easy to feed with 1/4 and 3/4 lines. The radiators are 10" X 100' aluminum tower sections with a 40' tubing T hat.
Does anyone have any experience with out-of-phase arrays? How significant are differences in current return efficiency between the 2 elements due to different ground conditions (eg one being flooded the other dry) or different radial field dimensions in an array of this type? Really worth doing??
TIA and 73 Bob HS0ZIA

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