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[TowerTalk] Re: Vertical array applications

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Subject: [TowerTalk] Re: Vertical array applications
From: btippett@alum.mit.edu (Bill Tippett)
Date: Tue, 20 Mar 2001 22:51:07 +0000
K3BU:
>Using "crummy" 2 el. parasitic verticals and dysfunctional 3 el. triangular 
>array sitting on the beach I came very close to W4ZV 10m score who was using 
>optimized 3 stack KLM of 6 el. (Both in NC) (yea, yea, I am 5x times better 
>operator, etc. :-)

Hi Yuri!

        Nice job from the beach!  Just for the record, here are the actual
numbers for the CQ WW CW on 10:

W4ZV            2009   37  138      31   1,021,825 PVRC
N2EE/4          1675   36  128             792,284  

        I modeled a 4-square vertical system over salt water just for my
own curiosity.  If memory serves me correctly, it showed about 10 dBi gain
from about 1-14 degrees.  A 3-stack of 6 el monobanders has just under
20 dBi gain at a peak take-off angle of 6 degrees with a vertical beamwidth
of 6 degrees.  For higher angles, the lower two Yagis have <1 dBi less gain
at at take-off of 8 degrees and a 7 degree vertical beamwidth.  At this point
in the solar cycle, the vast majority of propagation to Europe is 3-10 degrees,
so the <3 degree angles where a saltwater 4-square would beat a Yagi stack are
not very predominant.  Salt water verticals for a temporary expedition work
very well but you need 4 each 4-squares to close the gap with a 3-Yagi stack...
and even that would still be >3 dBi below a 3-Yagi stack at peak angles.  
(10 dBi/system + 6 dBi [for 4 each] = 16 dBi versus 19.6 dBi for a 3-stack.)

        Good luck this weekend and I hope you aren't trying to put up those
verticals in the 40 MPH wind-driven rain we're having here in NC today!

                                     73,  Bill  W4ZV (aka NY4A in CQ WPX)

                                                      


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