[TowerTalk] 80m Inverted L or 40m vertical

Jim Brown jim at audiosystemsgroup.com
Sun Dec 20 08:30:05 PST 2009


On Sun, 20 Dec 2009 13:42:38 +0000, Daniel Hileman wrote:

>since I am surrounded by trees on three sides

What kind of trees?  What kind of spacing(s) between supports? 

An inverted L as you describe should work very well on 80M, but I 
would try to keep the vertical portion at a distance from the trees. 
That is, try to support it midway between trees. A Tee vertical is 
even better than an inverted L -- the radiation from the top cancels 
out, and all of the radiation is vertical. 

Another design trick -- don't resonate the antenna on either 80 or 
40, but somewhere in between, and use an antenna tuner. Why? Because 
an exact half wave is a very high Z at the feedpoint, and very 
tricky to feed. The middle value is much more likely to be within 
range of your tuner. 

73,

Jim K9YC





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