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.

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

---------------
Take a look at any standard text (Kraus's "Antennas" for
example) and
you will see your definition isn't correct. Among other
characteristics,
a dipole antenna (also called a doublet) has two 'elements'
which are
equal in length (and commonly accepted to be 1/2 wave length
long). Doesn't
really matter is it's horizontal, vertical, an 'L', or some
randomly shaped
thingy, it's still a dipole.
Having used dipole antennas for over 30 years, I can't think
of a single
instance when I've fed one with two signals, no matter what mode
of use. I
~have~ fed them with a single signal and each 'element' of the
antenna be
180 degrees out of phase, but that's normal with any antenna fed
in the center.
Except for commercial and military applications, I can't think
of a single
multiplex amateur or CB example (two signals to the same
antenna).



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.
------------------
Also not true. At HF there is very little reason to worry
about using
a balun unless you have to do impedance transformations or are
feeding a
directional antenna. The primary result of an unbalanced signal
to a
balanced antenna is a very slight skewing of the radiation
pattern. Except
for directional antennas (beams) that 'skewing' of the radiation
pattern
isn't noticable (and not very noticable even with a directional
antenna).
If you will notice, I qualified all of the above to HF. At
higher frequencies
there is a more noticable change in radiation patterns because
of a balanced
to unbalanced condition. The example you furnished for baluns
is for the
VHF/UHF spectrum where pattern skewing ~is~ more noticable and
important.
Baluns are fine for when/where they are of use. At HF they are
at best
just another point of failure that isn't strictly needed.
'Doc