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

Ian Jackson wrote:
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.

I think he is totally unable to understand that an antenna and a transmission
line are two different things.

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).

That does not change a dipole into anything other than a dipole.

Feeding an antenna with any transmission line ill suited for the antenna
will of course lead to unwanted currents which will radiate to some
degree.

However, the antenna is defined by the geometry of the antenna and the
transmission line does not change the radiation of the antenna unless
you are doing something really stupid like taping the transmission line
to one of the elements of the antenna, which changes the antenna
geometry.

Feeding an unbalanced load such as a ground plane with balanced line
will also lead to unwanted currents which will radiate to some degree,
but the ground plane antenna is still a ground plane antenna.

It appears to me that someone has been reading too many Wikipedia articles - especially the ones that I wrote a long time ago.
Not to mention too many old editions of S9 and CQ magazine.

In the mid 60's - we talked about Tower Lighting - where the energy emitted from the antenna was being asorbed and reflected and radiated by the tower - which technicially was being electrostatically charged.

This was also the reason why HY Gain came up with the little egg beater / colineariator on top of their vertical antenna's such as the Super Magnum 117..

I think someone forgot to give Sheldon his medications today and he has gotten a little out of hand and the other techo geeks on this forum decided to attack.

Would everyone please take a chill pill and just calm down and relax.

I'm sure you can display your Pedant knowledge to someone a little less bright then you, say maybe the check out girl at the grocery store or the guy that pumps your gasoline into your vehicle at the gas station.