There is enhanced radiation in the direction of the top loading wire,
however it is not worth worrying about. It is about 1db with a 1/4 wl
inverted "L" that is 1/8 wl. high.
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] Inv L Directivity
From: Craig Clark <jcclark@wildblue.net>
Date: Fri, 31 Aug 2007 13:33:58 -0400
List-post: <mailto:towertalk@contesting.com>
> 8. Re: Topband: INV L Directionality
>
G3XAP wrote a number of articles in RadCom (RSGB magazine) about this
question.
December 1973 p 842 "160m dx from suburban sites"
November 1977 p 858 "The G3XAP directional antenna from the
lower frequencies"
Ashton's conclusion was there is enhanced radiation in the direction
of the top loading wire. His antenna used a 40-60' vertical element
and a 130' top loading wire. To get omni-directional performance, he
added more top loading wires.
73, Craig Clark, K1QX
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