[Antennas] balun and dipole question

Fri Dec 9 11:44:13 EST 2005

Guys:
A note on any doublet (read dipole antenna) fed with open wire. Sine the
line impedance is in the hundreds of ohms, the line will have some crazy
SWR, no matter what balun you have. Thus being the case, leave the antenna
in peace! That is to say, connect it directly to the antenna and le the
whole thing assume the impedance it will. In any case you'll have to take
care of matching at the transmitter end of the setup. What do you care what
actually happens with the antenna-line combination? Open line can stand
practically any SWR with little losses.
Remember power going in is going to get radiated, no matter what the SWR on
the line. What you have to do is to insure that under those conditions , the
transmitter will see a matched condition.
All this means the balun at the shack end of the line. 
As for the balun itself: what you need is a current choke balun , so as to
reduce possible unbalanced currents on the line. The lower they are the less
line radiation will be.
This is the gospel of W2DU and my humble experience.
Alex	4Z5KS
-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.371 / Virus Database: 267.13.13/195 - Release Date: 12/8/2005