[Antennas] Common Mode Choke

[Dan Richardson]

At 06:18 PM 3/10/2003 -0500, Ed wrote:
>     I want to clarify my first post. I use resonant antennas, no tuner, no
>balanced line. Simple setup...3 el Yagi 10/20...30/40 homebrew
>vertical...80/160 modified Battlecreek Special. Since there is no tuner,
>does it matter what I use for a common ground point ? I was thinking of
>using the power supply. About 70 watts is all I can run on CW and about 50
>on RTTY before I get RF in the computer. I plan on a choke between the rig
>and amp, and one between the amp and antenna selector switch. Does this
>sound reasonable ?? Thanks...73
>
>Ed W3NR
>
>Reply to:
>w3nr@arrl.net

Ed,

As you are using coax to feed all your antennas it would be best to place 
the choke/balun at the antenna feed point.  The idea is to try to reduce 
the common mode current on the transmission line. The wiLl help to keep the 
shack from getting *hot* and also will aid in maintaining a good pattern 
from your Yagi.

You may find some useful info at: 
http://home.iag.net/~w2du/Reflections2Chapter21SomeAspectsoftheBalunProblem.pdf

73
Danny, K6MHE