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[TowerTalk] antenna height

To: <towertalk@contesting.com>
Subject: [TowerTalk] antenna height
From: marko@robo.fe.uni-lj.si (marko@robo.fe.uni-lj.si)
Date: Fri, 10 Oct 97 13:34:09 MET
 
 
 Re:
 
 > >You neglected to  mention that you are also located on a hill.
 > >With rolling ground, it is possible for VERY  HIGH  antennas
 > >to virtually cover ALL angles that the ionosphere will support.
 > 
 > I dont think that is possible.  What you get from a hilltop is lowering of
 > the lobe.  I have done a lot of analysis using N6BV's & K6STI's programs.  A
 > single antenna on a hill at a preferred height looks like a stack on flat
 > ground.  You dont get ALL angles, even with a stack.  
 
 We would all agree that tophill antenna at optimal height will
 behave like a stack. At some other height gain peak would not be
 so pronounced but more wide variety of angles would be covered
 at less gain.
 
 But, having all angles at once may not represent an advantage.
 You may have reflections from several hop modes (1, 2 or 3 .. hops
 in the same moment) and this might demonstrate similar as improper phasing
 of stacks.  Result is lower signal strength compared to only one selected
 hop mode. And the fact, that narrow antenna radiation patterns are
 possible with longer yagis, makes these long yagis GOOD, not the slightly
 increased gain figure. That extra dB or so does not mean anything.
 
 In this moment/propagations I would vote for yagi in the sky with
 narrow radiation loop.
 
 From the tophill location,
 
 
 Marko, S50K
 

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