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Topband: gamma match a tower

To: <Topband@contesting.com>
Subject: Topband: gamma match a tower
From: "Jim Miller WB5OXQ in Waco" <wb5oxq@grandecom.net>
Date: Mon, 26 Nov 2007 21:02:12 -0600
List-post: <mailto:topband@contesting.com>
I have a 50' tower with a tribander on top with which to support an inverted L 
or a 1/4 wave sloper.  
....
>Why not just gamma match the tower and use it as a vertical.

Actually the tower is 52' with a force 12 c3 trapless tribander at the top and 
another 10' of mast with a dual polarity 10 element 2 meter beam on top of 
that.  What effect does the hf or vhf beam have on the action of the feed?  
also the tower is guyed at 45' and the guys are insulated from the tower.  
There is also a house bracket at 18' and it is electrically connected to a 
metal gable vent and there is a cross arm at 30' with a fm broadcast yagi and a 
scanner ground plane on it  The tower has 3 ground rods 1 by each leg with 30' 
of buried copper wire clamped to each leg and running 3 directions, 1 direction 
terminated with another ground rod and connected to the shack ground.  there is 
a alpha delta twin sloper mounted just 2' below the hf beam and it uses the 
tower as a counterpoise also.  At 47' there is a uhf atv yagi attached to 1 leg.
With all this baggage do you still think feeding the tower is a good idea?  I 
see far too many rf paths to decouple.

WB5OXQ
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