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Re: [TowerTalk] Hardwired coax

To: n3ox@n3ox.net, towertalk@contesting.com
Subject: Re: [TowerTalk] Hardwired coax
From: K7LXC@aol.com
Date: Mon, 30 Apr 2007 12:19:11 EDT
List-post: <mailto:towertalk@contesting.com>
 
In a message dated 4/30/2007 9:06:10 A.M. Pacific Daylight Time,  
n3ox@n3ox.net writes:

>  I checked the impedance transformation that you'd get from 2  inches of
several different types of parallel line at 14MHz.  With  "Open Air
Dielectric 19/1.30" I get 50+j6 ohms at the far end when the line  is
looking into a 50+j0 load.

>  In other words, no big  deal.


    That was my feeling but the antenna - a MonstIR -  went from 1.3 or so to 
3:1 - a big change. What else could make that much  difference?
 
    While hardwiring the coax is less than optimal,  it seems to me that you 
could see the impedance bump with a TDR or similar but  the RF really doesn't 
care how it's transported (so it's out-of-balance for 6  inches - so what?). 
 
    The feedline is acting like a feedline, it's  connected to the antenna 
and the antenna is acting like an antenna so I'm  trying to figure out what 
would cause the SWR jump. 
 
    More input appreciated.
 
Cheers,
Steve     K7LXC
 
        








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