Date: Wed, 21 Dec 2016 14:41:54 -0500
From: Michael Clarson <wv2zow@gmail.com>
To: Jim Thomson <jim.thom@telus.net>
Cc: "TowerTalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Double Coax Runs to Reduce Loss?
Perfectly clear. However, would the same math apply if the pair of cables
were treated as a shielded balanced line? I could see some applications for
that. --Mike, WV2ZOW
## a buddy did just that..to feed a 100 ohm Z quad loop. 100 ohms between
the 2 x center conductors. Braids bonded at each end. = shielded balanced
line.
## dunno what the total system loss would be in that config. He used no
balun at the
feedpoint. Forget what he did at the shack end.
## 75 ohm, kw rated twinlead would have been a lot lighter.
## He could have used a quarter wave of 75 ohm coax, as a matching section, to
get from 100 ohms down to 50 ohms.
You would still require a CM choke at the feedpoint though.
## an L network would easily transform the 100 ohms down to 50.
Jim VE7RF
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