I have been reading all the answers to your questions. I have 2 questions.
Firstly I have had 3 160 inverted L's at different locations.
My questions for you are: Why 175 feet.?. Where does that come from.?. Every
one I've used has been 66 feet vertical and 66 feet horizontal. 132 feet is
the common accepted starting point for 1/4 wave 160 meter antennas. Ideally
an inverted L is a 1/4 wave vertical with the voltage portion bent over
horizontally. That's where the 66 ft vertical and 66 ft horizontal comes
Why the 75 ohm cable.?. The input impedance of an inverted L with a
reasonable ground system is slightly less than 50 ohms.
BULLHEAD CITY, AZ
Everyone in the world is
entitled to be burdened
by my opinion
----- Original Message -----
From: DENNIS BRICKEY
Sent: Friday, August 29, 2008 20:58
Subject: [TowerTalk] Inverted L Question
I realize this is not a tower question, but the antenna gurus hang out
here.Â Hopefully some bandwidth can be tollerated for an antenna question.
IÂ am working on a 160 meter inverted L and having some difficulty getting
the match correct.Â I'd appreciate any input.
175' total wire length.....100' vertical 75' sloping horizontal
23 (qty) 130' radials.
Fed with 75 ohm cable hardline through a variable capacitor.
I've trimmed and extended the vertical section and adjusted the cap with
each length change.Â The low swr point is alwaysÂ 2.8:1.Â Essentially the
only thing changing is how
much the capacitor meshes.Â
I started with 16 radials and thought adding more would help the match, but
it has not changed.
All advice appreciated.
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