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Re: Topband: Effect of trees- tree appreciation

To: topband List <topband@contesting.com>
Subject: Re: Topband: Effect of trees- tree appreciation
From: Gary and Kathleen Pearse <pearse@gci.net>
Date: Sat, 10 Aug 2013 09:08:16 -0800
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Thank you all for the replies regarding the "T" versus "L" rebuild for my 160 
antenna. I'm on a 120x120' city lot in Fairbanks. For fun look me up in QRZ, 
under 'Detail' zoom in for a satellite view via Google, then switch to a street 
view to see the trees. The motorhome is gone, the motorcycle is replaced with 
another, and the tower and trees still stand. 

The T would be strung between two spruce trees to the W of the home. Not the 
best scenario as the available tree spacing is a close ~75', the T wires would 
be touching the top of each tree trunk, and any excess for trim would drop down 
next to each trunk as well. A breeze would flex the trees and cause the 
vertical portion to rise and fall possibly affecting tuning.

The L (mimicking my former 160 antenna that came down with a blown tree) would 
climb a 75-80' tree adjacent to the SW corner of the home, be held away 5-7' 
from the trunk via branches except for the very top, and the remaining ~55' 
horizontal portion would head towards the street to the south but not reach the 
support, again at 75-80'. Eight tuned radials at ~15' are strewn where possible 
around the property. 

After some thought and your discussion, I think I'll repeat the L as it's easy 
to shoot the support ropes from the house roof. The T would be harder, and one 
end would be close to the power line that adjoins the north edge of the 
property. 

Adjusting resonance for the T would require lowering the whole deal a few times 
from both supports. Adjusting the L is simpler and only requires loosening the 
horizontal leg and shortening or lengthening the base of the vertical part. 
Plus I already have a big feed line choke and 3:1 matching unit built from the 
previous setup.

We'll see what happens,

73, Gary NL7Y
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