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[TowerTalk] Flaky dipole

To: <towertalk@contesting.com>
Subject: [TowerTalk] Flaky dipole
From: "Jim Thomson" <jim.thom@telus.net>
Date: Tue, 2 Aug 2016 09:31:29 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
From: Grant Saviers <grants2@pacbell.net>
To: Tom Osborne <w7why@frontier.com>, towertalk@contesting.com
Subject: Re: [TowerTalk] Flaky dipole


First, I have to admit to a strongly held opinion that "ladder line" is 
one of the worst feedlines one can chose for getting the rf to the 
antenna.  By "ladder line" I mean the windowed polyethylene insulated 
"twin lead". The "low loss" mystique is misleading.

Yes, it is low loss when suspended in free space in a vacuum.  If it is 
wet or dirty or in contact with most anything the loss goes WAY up.
see  http://www.k6mhe.com/n7ws/Ladder_Line.pdf   and 
http://www.karinya.net/g3txq/wet_ll/

## can u get the  300/450 ohm line..without the windows ?? 
Seems to me that 300 ohm TV type line back in the 60s /70s
had no windows, I remember it well.  It was also available
in a windowed variety. 

##  along the same subject, back in the 70s, solid twinlead
was available in 75 ohm.  Came in 2 x formats, small and large.
The large stuff would easily handle high power.   Back then,
the kw rated 75 ohm twinlead was fed  directly to the dipole,
then the other end had a PL-259 installed on it.   Dunno if its
still available or not.   With no windows in the line, water wont collect.

##  On a similar note, a buddy used paralleled 50 ohm coax,
to make  100 ohm, shield, balanced line for his quad project.
Shield tied together at each end.  100 ohm Z between the
2 x center conductors.   Made from 2 x 213-U  taped together
every few inchs.  Can also be done with 2 x RG11  to make
150 ohm, balanced, shielded line. 

Jim   VE7RF 
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