[TowerTalk] Balun question

[K7LXC at aol.com]

Howdy, TowerTalkians --
 
    I'm putting up a huge F12 6M beam and the B1 balun  is AFU - the SO-239 
on it pulled out. :-(
 
    The non-technical support advice from F12 was to  wind an RF choke. Umm, 
okay. I'm not a huge fan of them on HF so Lord knows what  happens when you 
use one at 50 mHz. 
 
    Can anyone tells me what happens? Should I be using  a current-type balun 
ala' W2AU or should I wind the choke? If so, what size is  it? 
 
    Part deux. In my meager understanding, a balun  is a transformer that 
goes from balanced-to-unbalanced (bal-un, get  it?) vis-a-vis a feedpoint. It 
also functions as an RF choke to prevent RF  from spilling down the outside of 
the shield. A coax wound RF choke  doesn't really "transform" anything but does 
choke the stray RF trying  to come down the outside of the shield. Am I close? 
 
    Anyway, all comments appreciated. 
 
Cheers,
Steve     K7LXC
TOWER TECH 



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