[TowerTalk] Simple 1:1 Guanella Balun

[Mark .]

Hello TowerTalkers,

Another inquiry for the neural network. Do any of you have practical 
experience with the simple Guanella choke balun? I learned about this from 
either the ARRL antenna book, or Jerry Sevick's book on making baluns and 
ununs (not a misspelling).

There is a clever way to wind coax around a ferrite core such that it enters 
and leaves the core in an in-line manner: eg., the coax enters and leaves in 
positions 180 deg apart. You wind 1/2 of the core, then cross over to the 
other side, and continue winding in such a manner as the turns always pass 
throu the center of the core in the same direction. This effectively chokes 
off the RF from the outside of the coax shield

I have used this on some homebrew, coax-fed, fan dipoles, placing the core 
inline at the antenna feedpoint. Using RG-58 yielded close to 12-15 turns on 
an FT-240 size core. The performance seemed good, with no TVI reported.

I would like to try using a simple 1:1 Guanella balun with an unbalanced 
tuner to feed antennas having parallel feedlines. Any comments or 
experience?

Thanks,

--...MARK_N1LO...--