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[TowerTalk] 75 ohm - v - 50 ohm coax

To: <towertalk@contesting.com>
Subject: [TowerTalk] 75 ohm - v - 50 ohm coax
From: "Jim Thomson" <jim.thom@telus.net>
Date: Tue, 19 Feb 2013 06:21:28 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Another point with respect to loss in that coax. Because its diameter 
is quite large, loss is MUCH lower than the RG8-size coax we usually 
use. It is also lower because the loss in ANY coax at HF is I-squared R 
loss in the copper, and the current in 75 ohm coax is proportionally 
less for the same power level. 

73, Jim K9YC


##  say what ?   What about skin effect at HF ?  
.875” heliax uses a  hollow cu tube.  If it was solid CU center
conductor, loss’s would NOT decrease. 

##  Fine for your to recommend  the use of 1” 75 ohm coax for a high dipole,
but do you have any clue how heavy that is gonna be ????   Never mind
the  “balun” at the feedpoint.  

Lets get practical for once. 

Jim  VE7RF
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