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Re: [TowerTalk] Inverted L Question

To: "DENNIS BRICKEY" <>, "towertalk" <>
Subject: Re: [TowerTalk] Inverted L Question
From: "N7mal" <>
Date: Sat, 30 Aug 2008 08:12:24 -0000
List-post: <">>
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.

Everyone in the world is
entitled to be burdened
by my opinion

----- Original Message ----- 
To: towertalk
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. 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. 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. The low swr point is always 2.8:1. 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.

Any Ideas?

All advice appreciated.


Dennis N4DD


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