On Sun, 14 Sep 2003 21:00:40 -0500, "Dave VanHorn"
wrote:


"'Doc" wrote in message ...
Dave,
Just so you will know in the future, the dipole is
a dipole, balun or no balun. It's still a balanced
antenna, but fed with an unbalanced feed line.

no, it's not.

Yes it is.

A dipole antenna is a straight electrical conductor measuring 1/2
wavelength from end to end and connected at the center to a
radio-frequency (RF) feed line. This antenna, also called a doublet,
is one of the simplest types of antenna, and constitutes the main RF
radiating and receiving element in various sophisticated types of
antennas. The dipole is inherently a balanced antenna, because it is
bilaterally symmetrical.

Ideally, a dipole antenna is fed with a balanced, parallel-wire RF
transmission line. However, this type of line is not common. An
unbalanced feed line, such as coaxial cable, can be used, but to
ensure optimum RF current distribution on the antenna element and in
the feed line, an RF transformer called a balun (contraction of the
words "balanced" and "unbalanced") should be inserted in the system at
the point where the feed line joins the antenna.

in order to be a dipole, it has to be fed with two signals, 180 degrees out
of phase, and equal ampliude.

otherwise, it's a monopole, with a counterpoise.

So I can feed my Ground plane or quad with a balun, then its a
dipole?

do you not see the difference between a driven, and a passive element

You think the end thats fed with the shield of the coax is passive?
Come on over and grab the end of my dipole, (fed with coax and no
balun), when I have 1Kw running to it. You will change your mind
about it being passive.



Do you really mean a balun,
or do you mean a coaxial choke? At HF either will work.
'Doc

whichever way you do it, you need to feed it balanced.


You will notice very little, or more likey no difference between a
dipole fed with or without a Balun.