[TowerTalk] KT36 Balun
jim.thom at telus.net
Mon Apr 28 11:52:29 EDT 2014
Date: Sat, 26 Apr 2014 19:43:57 -0700
From: "Jim W7RY" <w7ry at centurytel.net>
To: <towertalk at contesting.com>
Subject: [TowerTalk] KT36 Balun
Which balun do you recommend for the M2 KT36? A voltage balun or a current balun? I run 1500 watts during RTTY contests.
I?m planning on winding my own. I have Jerry Sevick?s book on building them.
## You need a 1:4 balun..since the ant is 200 ohms. Use either a balun designs 1:4 balun..like a 5 kw unit,
or get one from array solutions. Array solutions will make a 1:4 balun in any power rating you want.
## Then follow it up with a 1:1 choke balun, like a bead balun made from type 43 or type 33 large diam beads
slid over RG-213 or RG-393 coax. Or use a k9yc design, optimized for 20-10m. Or get a 1:1 choke balun
from baluns designs.
## The 1st balun does the 1:4 transformation..right at the feedpoint. The 2nd balun, 1:1 choke type...is right in front
of it. The 2nd balun kills any residual RF. Between the two of em, you end up with your 1: 4 transformation, plus
a sky high choking Z.
## IE; 50 ohm coax up the tower, then 1:1 choke balun, then 1:4 balun. Most 1:4 baluns will do the transformation
job ok, but will not have the high choke Z you are after.
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