Topband: Best Receive Antenna over Sloping Terrain?

Lee STRAHAN k7tjr at msn.com
Sat Sep 2 14:37:14 EDT 2017


   Greetings Topband antenna guys,
     As a manufacturer of shortened vertical element receiving antennas, I have been asked the question about sloping ground many times.
It occurred to me one day that I could use Eznec to solve the question. What I did was to slope the elements with respect to Eznec zero elevation and made the angle of the elements to the ground the same as if the earth under your sloping antenna field suddenly went flat and the elements were then leaning. I lean the verticals in Eznec to the angle offset of the questionable uneven earth.
   It is not too hard to program these angles into Eznec and then when you view the resultant plot you can turn your head or viewing angle so that the plot zero elevation is at the slope angle or if you have any vertical elements you simply view it at an angle where the vertical portions are vertical in your view.
   It is a little hard to describe this but starting with a single vertical element should help to understand the process.
      What I found generally was that the patterns of the vertical antennas or the take off angles mostly simply followed the rising ground and the pattern stayed mostly the same up to a point where the difference in height of the verticals was about 1/3 of the height of the element.
   I suspect Eznec could easily be used on other style antennas like Beverages or loops, etc. using my technique with Eznec.
  Your results may vary . I have not tried other style antennas except shortened verticals. I would be interested in hearing results if someone tries this.
Lee   K7TJR    OR


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