"'Doc" wrote in message ...


Dave,
----snipped--------
passive dosen't mean 'no current flow' in this context, it means not
driven
from the feedline.


And the 'passive' element of a dipole antenna ~isn't~ fed
from the feed line? Confusing'er and confusing'er.

i've been maintaining that a properly implemented dipole does not have a
passive element.
both halves should be driven. in the case where it's fed directly with
coax, it isn't clear to me wether the shield connected element is getting
current from the inside of the shield, or by illumination from the center
connected element. i suspect both are true, to some degree.
certainly the rf on the feedline now couples into the system, and makes
things even fuzzier.

I thought both 'halves' of a dipole were fed by the feed line, certainly
every one that I've made, or seen have been.

No, I'm aware of that. But are you the one who 'minted' the
"two signal" way of looking at a single signal? Like some other
types of esoteric thinking you have to be very careful where
they
are applied, and how.

i wasn't as clear as i intended to be.
you can view the output of a balun as two out of phase signals, at half the
input power, or a single balanced signal. i wasn't sure if the fellow i was
talking to at that point, knew what you get at the output of a balun.

If you aren't careful, they deteriorate
into nonsense as has happened here. If how you think about a
dipole antenna helps you with what you're doing, then fine, have
at it. That doesn't make it 'correct' or the 'right' way of
doing
things, though, and it is very confusing to someone who isn't
familiar with that particular 'theory' of operation. If you
want to
call a dipole by another name, that's fine too. But it don't
make
it so.

no, the point i was making is that a dipole, is designed to be fed from a
balanced source, and it does make a difference. the magnitude of the
difference, in gain, radiation, and rf on the feedline /when feeding it
unbalanced/ is debatable.

Aunt Martha wasn't born with wheels, so she really isn't
a Buick... no matter what she thinks.
'Doc

beep beep /vbg/

"Frank Gilliland" wrote in message
...
In , "Dave VanHorn"

wrote:


And BTW, a 'doublet' only means the antenna has two elements. That's
all.

any two elements, anywhere in space?

Pretty much.

i think not.

Then why don't you explain why you think not?

maybe by purist definition, but putting the second element at a significant
distance makes it more an independent antenna, than part of a system with
the first one.
also, placing them very close together and in parallel would make them
essentially one element.

On Tue, 16 Sep 2003 16:19:28 -0500, "Dave VanHorn"
wrote:

i wasn't as clear as i intended to be.
you can view the output of a balun as two out of phase signals, at half the
input power, or a single balanced signal. i wasn't sure if the fellow i was
talking to at that point, knew what you get at the output of a balun.

Yeah, that was that Dave Vanhorn fellow you were talking to. I don't
think he quite understands what a balun is or what it does.

In , "Dave VanHorn"
wrote:


"Frank Gilliland" wrote in message
.. .
In , "Dave VanHorn"

wrote:


And BTW, a 'doublet' only means the antenna has two elements. That's
all.

any two elements, anywhere in space?

Pretty much.

i think not.

Then why don't you explain why you think not?

maybe by purist definition, but putting the second element at a significant
distance makes it more an independent antenna, than part of a system with
the first one.

Not necessarily. Sometimes a doublet is used for direction-finding by using the
phase relationship between the two elements while they are a significant
distance apart. In that case, "wider is better". And just for the sake of
discussion, a pair of TV 'rabbit ears' is considered a doublet. Even though it
uses balanced transmission line, it is not a dipole because it doesn't function
as a dipole.

also, placing them very close together and in parallel would make them
essentially one element.

Not even that -- they would no longer be elements of an antenna, but two
conductors of a transmission line.






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In , "Dave VanHorn"
wrote:

snip
no, the point i was making is that a dipole, is designed to be fed from a
balanced source, and it does make a difference.

If you are saying that a balanced load should be fed from a balanced source,
I'll buy that. But don't forget that a dipole doesn't necessarily need to be
balanced. It's just as easy, if not easier, to shift the feedpoint (gamma match)
as it is to wind a balun.

the magnitude of the
difference, in gain, radiation, and rf on the feedline /when feeding it
unbalanced/ is debatable.

I dunno... I've pegged my FSM more than a few times holding it next to a coax.
But that may not be such a bad thing if you want some vertical polarity while
using a horizontal dipole.





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This thread has not got out of hand, opinions are like asshole every body
has one, it seams that I have the Gods of the group in a heated discussion,
let it go on, do not kill a good thread.

br549

"Swan Radioman" wrote in message
...
On Tue, 16 Sep 2003 03:03:03 GMT, "BR549" wrote:

Thanks everybody, after I sort out all this info I will have a PHD in
Dipole
Antennas


Regards,
br549



Mitch;
Sorry this thread has gotten out of hand. Dipoles are one of the
easiest antennas to build and get working. Plus its a lot of fun to
play with.

Here is a link that will help you calculate the length of the wires.

http://www.qsl.net/w4sat/calc.htm