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Ian Jackson[_2_] · July 11th 12, 07:33 PM posted to rec.radio.amateur.antenna

In message ,
writes
Szczepan Bialek wrote:

Simply same of you do not know that "dipole" is a radiator and counterpoise.

A dipole does NOT have a counterpoise.

As I keep saying, I'm convinced that Szczepan is thinking of a situation
where a dipole fed directly with coax. He may have seen diagrams which
show this, and they have become fixed in his mind.

Then, because the coax is (usually) grounded at the TX end, he believes
that the leg of the dipole, which is connected to the coax screen, is
also grounded - and therefore it serves the function of a counterpoise -
like you might use in a situation where the antenna is a directly-fed
end-fed wire situations, and it is not possible to get a good ground
connection.

In a way, Szczepan is sort of right. Consider the situation where a
dipole (no balun) is connected to the TX via essentially zero length
coax, and the TX chassis is not well grounded. [For example, possibly
there is a physical safety ground connection, but it is too long to be
effective at RF.] The 'ground' side of the of the dipole would indeed
function as a counterpoise, which might - or might not - radiate
effectively (depending on its height, its physical relationship relative
to the 'live' leg etc).

Now increase the length of the coax. At some stage, we would no longer
consider the 'ground' leg as a counterpoise, and think of it simply as
the other leg of the (directly connected) dipole.

However, while Szczepan may have a point if he is thinking of a
directly-connected dipole, he is obviously talking total nonsense if he
is referring to a dipole fed via a balun, or from a balanced tuner via
twin feeder. I fear that he is incapable of taking a rational, lateral
view of things, and therefore will continue to repeat his essentially
incorrect mantra.
--
Ian