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Re: [TowerTalk] [CQ-Contest] Stacking on separate towers, take off angle

To: towertalk@contesting.com
Subject: Re: [TowerTalk] [CQ-Contest] Stacking on separate towers, take off angles?
From: David Gilbert <xdavid@cis-broadband.com>
Date: Fri, 15 Mar 2013 10:29:01 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
The overall physics behind horizontal stacking of horizontally polarized 
and antennas is pretty much the same as if we were talking about feeding 
two vertical antennas (i.e, a phased vertical array). You get additions 
and cancellations depending upon the distance between the two antennas, 
the lengths of the phasing lines, and the direction involved.  The nulls 
and peaks are less likely to be predictable, though, and probably 
wouldn't be as well defined (i.e., I don't think you'd get a sharp null 
in some direction) since the horizontal elements don't look like a 
"point" when viewed from above.  I could imagine that the mutual 
coupling between the two antennas is a strong function of the beamed 
direction as well.
About the only direction where you can say with any certainty that you 
have a beneficial effect is when you are beaming broadside to the 
combination of the two antennas and are feeding them with transmission 
lines of equal electrical length.
73,
Dave   AB7E



On 3/14/2013 4:26 AM, Cqtestk4xs@aol.com wrote:
There's the rub...they may work.  Unless you can analyze them and  include
data for length of feedline, distance and terrain it's all guess  work.
Make one feedline 1/2 wavelength and you'll have a great local ant  but one
that pretty well sucks for DX.  Plus, if they are more than a  wavelength apart
the "stacking effect" starts to drop.
However, it never hurts to try. Bill K4XS/KH7XS by 1In a message dated 3/14/2013 10:34:25 A.M. Coordinated Universal Tim,
jpklemola@gmail.com writes:
No problem.
Just connect them and if they work as separate antennas, they  pretty
often work stacked,  too.
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