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Re: [TowerTalk] RG11 Cable

To: <n4zr@contesting.com>, "Jim Brown" <jim@audiosystemsgroup.com>
Subject: Re: [TowerTalk] RG11 Cable
From: "Stan Stockton" <stan@aqity.com>
Reply-to: Stan Stockton <stan@aqity.com>
Date: Tue, 25 Aug 2009 18:55:47 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I am still using 3/4" 75 ohm hardline for the majority of my antennas. 
If it is a 50 ohm antenna and convenient I will make the hardline a 
multiple of a half wavelength.

Many of the antennas are designed for about 36 ohms and I step then up 
to 75 ohms from the driven element to the hardline with a odd multiple 
of a quarter wavelength of 50 ohm cable and then use a 12th wave 
transformer in the shack.

There is nothing critical or complicated about it that I can tell. All 
you have to remember for .66 VF coax is 30 inches for 15M.  You can 
scale that to any of the normal bands - 45 inches for 20M, 90 inches for 
40M, 22.5: for 10M, etc.  It is convenient to not have to worry about 
the SWR changing when you change a coax length and have a good feeling 
when you look at the thing with a 50 ohm analyzer.

Stan, K5GO 

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