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Re: [TowerTalk] Inverted L..........

To: "" <>
Subject: Re: [TowerTalk] Inverted L..........
From: "Jim Brown" <>
Date: Tue, 25 Dec 2007 09:30:23 -0800
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On Mon, 24 Dec 2007 14:48:58 -0600, John wrote:

>Although I have worked 78 entities in a very short period of 
>it just doesn't seem like this thing is playing very well.  The 
>vertical portion is about 3' to 4' from the pine tree.  

You've worked 78 entities on 160M in a short time and you're 
complaining? I've worked 61 in a year and a half and I'm thrilled!  
You guys on the east coast have all the fun with DXCC, with all 
those entities in EU and Central America. :) 

There are four things that can make it play better for DX, but 
they may not be practical at your QTH. 1) Make the vertical 
section taller. 2) Move the vertical section further from the tree 
(loss in the tree MIGHT be a small issue on 160, but I've seen no 
science on this). 3) Add more radials. 4) Turn the horizontal 
section into a Tee so that there's less high angle radiation. 

All of these are "a dB here and a dB there" sort of improvements. 

As to your impedance measurements -- you should really try to 
measure at the base of the antenna with a decent bridge. I'd bet 
that the Z is a lot lower than you think it is. If you measure in 
the shack, you've got to translate complex R + jX measurements to 
the other end of the feedline to get it right, and to do that, 
you've got to know the ELECTRICAL length of the feedline to fairly 
good accuracy. 


Jim Brown K9YC
Santa Cruz, CA


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