On Mon, 4 Apr 2005 13:06:59 -0700, "denton"
wrote:

Hi all......
I have a ground mounted 40 ft vertical wth an extensive buried radial system
that I have been using with good success on 40 thru 10 meters and have been
feeding it with 50 ohm coax to a 4 to 1 voltage balun at the base of the
antenna.
I recently tried feeding the antenna with 450 ohm twin lead and a Johnson
Matchbox with the twin lead parallel to the ground at about 6 inches
elevation.
I am pretty gratified to find the Matchbox will do a fine job of balancing
and matching on 80 thru 10 meters.

Anyone else try this?

I haven't tried feeding an unbalanced antenna with balanced line before,
unless there is a balun at the feedpoint of the antenna...have always
thought balanced line will only feed a balanced antenna....the exception
being an end fed zepp, or a 30 ft vertical with one 30 ft counterpose.


Dear Denton,

This is not to say that it will not be a problem in some way. You get
away with it primarily because the tuner end of the balanced line is
connecting only to the link - therefore floating (except for some
capacitive coupling from the link to the tank circuit).

To a large degree, the fact that the ground plane antenna is very much
unbalance, the twinlead doesn't have any way of knowing this and
doesn't care.




Bob, W9DMK, Dahlgren, VA
Replace "nobody" with my callsign for e-mail
http://www.qsl.net/w9dmk
http://zaffora/f2o.org/W9DMK/W9dmk.html