Ian White wrote:
The Natural Philosopher wrote:

[Ian White had written}
Likewise the final paragraph about baluns being generally associated
with twisted pair. A balun makes a transition between a "balanced"
(ie physically and electrically symmetrical) system, and an
"unbalanced" system like coax. Andy is talking about the transition
between the dipole (balanced) and the top of the coax feedline
(unbalanced), which is a classic application for a balun.

No, you have just refuted your own argument.

What I just gave is the normal textbook description of what a balun is
for. If you find that in any way self-contradictory, the problem is all
yours.

The cable can ot be considered unbalanced just because one side of it
is earthed at one end, that is exactly what you said, and I agree..
and it make bugger all difference if you actually have no cable at
all, and simply earth one side of the dipole - in which case its a
quarter wave whip and a ground plane.

In standard engineering usage, coaxial cable is called "unbalanced"
because it doesn't have the same left-right symmetry that a "balanced"
dipole does.


A balun may also include an impedance transformation, but that is
categorically *not* its primary function.


No, and yet in his case its its ONLY valid function.

Again, it's only wrong according to your own misunderstanding of the
subject.


(PS: Just read your other two postings, and the same comments apply.)


I suggest you go and actually study the theory then.

Oh I have, I have... and also designed baluns, built them, measured
them, used them, written about them and had more discussions about them
than you could possibly imagine.

That's why I can say with confidence that Andy and I are right in the
mainstream on this subject, and you are in a minority of one.



We will have to agree to disagree.

You gave repeatedly stated that the concept of balancing cant apply to
an RF dipole, which I agree with, and yet you persist in saying that you
need a balun to properly match it to an unbalanced coax, which by your
definitions, is also a relatively meaningless term, since at RF the
actual voltages with respect to ground at the far end are fairly
indterminate.

You are just parroting two statements, probably culled from simplistic
text books, without actually thinking what they actually mean when put
together.

If you cant see the logical contradictions in your arguments, I cant
really have anything more to say.