[TowerTalk] Balun question

[k3bu at optonline.net]

> 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 
> 

For mono-band antennas I prefer "bazooka" balun. It is a quarter wave stub wired per instructions in handbooks etc. Advantage is low loss, no ferites, it is a bal-un and also bandpass filter. Also widens the bandwidth of antenna, its reactance works opposite the antenna's reactance, SWR curve is more flat. 
 
Yuri, www.K3BU.us
www.TeslaRadio.org