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Old September 10th 08, 09:16 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

I am putting up a Carolina Windom using ladderline instead of the
variant that uses ten feet of coax.
As an OCF the antenna should drive RF to radiate from the vertical
ladderline (coupled to the coax via 4:1 balun)

Odd multiples of the desired wavelength are recommended for the
calculated length of the vertical component.

I have 47 feet of ladderline and my question is:
Does it make much difference whether a low odd multiple or high odd
multiple of the wavelength is used. i.e., 1/3 lambda, 3/5 lambda, 5/3, etc?

I don't have direct access to EZNEC right now.

If you gotta flame, OK but at least this is question about ANTENNAS.

JOhn
AB8O
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Old September 10th 08, 09:29 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

On Wed, 10 Sep 2008 16:16:59 -0400, john Wiener
wrote:

I have 47 feet of ladderline and my question is:
Does it make much difference whether a low odd multiple or high odd
multiple of the wavelength is used. i.e., 1/3 lambda, 3/5 lambda, 5/3, etc?


Hi John,

Your reference to Odd Multiples is incomplete. It is Odd Multiples of
quarterwave lengths: 1/4, 3/4, 5/4, and so on; otherwise every odd
number coming down the pike (3/7ths, 7/9ths....) would lead to unusual
claims that were wholly fanciful.

If you gotta flame, OK but at least this is question about ANTENNAS.


Windoms, Carolina Windoms, OCF dipoles, and any number of names for
what the authors "think" represents the same antenna, is a can of
worms from the beginning (as evidenced by the Odd Multiples, a loose
reference you undoubtedly picked up from one of those seers). You
would get further if you simply state what you want to achieve instead
of trying to put lipstick on this pig.

73's
Richard Clark, KB7QHC
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Old September 10th 08, 09:46 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

Richard Clark wrote:
On Wed, 10 Sep 2008 16:16:59 -0400, john Wiener
wrote:

I have 47 feet of ladderline and my question is:
Does it make much difference whether a low odd multiple or high odd
multiple of the wavelength is used. i.e., 1/3 lambda, 3/5 lambda, 5/3, etc?


Hi John,

Your reference to Odd Multiples is incomplete. It is Odd Multiples of
quarterwave lengths: 1/4, 3/4, 5/4, and so on; otherwise every odd
number coming down the pike (3/7ths, 7/9ths....) would lead to unusual
claims that were wholly fanciful.

If you gotta flame, OK but at least this is question about ANTENNAS.


Windoms, Carolina Windoms, OCF dipoles, and any number of names for
what the authors "think" represents the same antenna, is a can of
worms from the beginning (as evidenced by the Odd Multiples, a loose
reference you undoubtedly picked up from one of those seers). You
would get further if you simply state what you want to achieve instead
of trying to put lipstick on this pig.

73's
Richard Clark, KB7QHC

Richard

Fair enough. You used the "L" word.

I want to use this antenna for 30M but also for multiband use.
Thanks for correcting my fuzzy math.

I have read several articles that state inferiority of the OCF to the
dipole. Perhaps they are misunderestimating?

John
AB8O
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Old September 10th 08, 10:21 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

On Wed, 10 Sep 2008 16:46:00 -0400, john Wiener
wrote:

I want to use this antenna for 30M but also for multiband use.
Thanks for correcting my fuzzy math.

I have read several articles that state inferiority of the OCF to the
dipole. Perhaps they are misunderestimating?


Hi John,

You have a problem with too many references with too little knowledge,
I'm afraid. Of course my own posting could easily fulfill that
dilemma, but that doesn't stop me from proceeding.

First off, the OCF is a dipole. And here begins what would be a
pointless debate of semantics into the meaning, definition, and quest
for what a dipole "is." As a dipole, it simply has a different
feedpoint placement along its length.

As it happens, that same wire will resonate at very nearly every
harmonic no matter where it is tapped: in the conventional middle, or
to one side by whatever degree. What changes by shifting that point
is the match of resonance.

Over the course of time, some wag either brute forced worked it out,
did a model, or thought he measured it to demonstrate that a certain
sweet spot, in combination with a 4:1 BalUn produced an antenna that
was a most useful connection to a rig for little further tuning.

In some large part, that is true. The devil is in the details
however, and those details are rarely discussed by the sons of that
cult of worship. You may well already be aware that such an antenna
is prone to Common Mode problems (otherwise claimed as benefits by
those who couldn't solve them); and these problems are directly
attributable to the off center (or unbalanced) state. As truth be
known, nearly every dipole is unbalanced to some degree, so this OCF
is more so, and deliberately more so.

How do people reconcile using their own common dipole with its
unintended unbalance? Choking. Hence the same admonition goes with
the OCF, by that greater degree of "more so." Thus if you can
successfully choke it, the OCF could bring you all the claimed
virtues.

Now if you only knew the location of that sweet spot drive point....

If you got this far, we go to that length too.

73's
Richard Clark, KB7QHC
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Old September 10th 08, 10:39 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

john Wiener wrote:
I am putting up a Carolina Windom using ladderline ...


Technically, if you use ladderline (or twinlead) it
is not a "Carolina Windom" and also not a "Windom".

I ran such an off-center-fed dipole 57 years ago
at Texas A&M fed with 300 ohm twinlead and a 6:1
Heathkit balun at the DX-40. It worked very well.
--
73, Cecil http://www.w5dxp.com


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Old September 11th 08, 02:05 AM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline


Hi John,

You have a problem with too many references with too little knowledge,


You talkin' to ME?

I'm afraid.


I thought so.

Of course my own posting could easily fulfill that
dilemma, but that doesn't stop me from proceeding.

First off, the OCF is a dipole. And here begins what would be a
pointless debate of semantics into the meaning, definition, and quest
for what a dipole "is." As a dipole, it simply has a different
feedpoint placement along its length.

As it happens, that same wire will resonate at very nearly every
harmonic no matter where it is tapped: in the conventional middle, or
to one side by whatever degree. What changes by shifting that point
is the match of resonance.

Over the course of time, some wag



(I would assume that would be Windom)


In some large part, that is true. The devil is in the details
however, and those details are rarely discussed by the sons of that
cult of worship. You may well already be aware that such an antenna
is prone to Common Mode problems (otherwise claimed as benefits by
those who couldn't solve them); and these problems are directly
attributable to the off center (or unbalanced) state. As truth be
known, nearly every dipole is unbalanced to some degree, so this OCF
is more so, and deliberately more so.

How do people reconcile using their own common dipole with its
unintended unbalance? Choking. Hence the same admonition goes with
the OCF, by that greater degree of "more so." Thus if you can
successfully choke it, the OCF could bring you all the claimed
virtues.

Now if you only knew the location of that sweet spot drive point....

If you got this far, we go to that length too.


Gee, I think I follow, professor. Do tell.

73's
Richard Clark, KB7QHC


Appreciate the warning about choking beyond the balun. Ferrite beads
come to mind...easy and I don't like "wasting" cable in coils but I'll
do it if necessary.

73

John
AB8O
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Old September 11th 08, 02:18 AM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

Cecil Moore wrote:
john Wiener wrote:

I am putting up a Carolina Windom using ladderline ...



Technically, if you use ladderline (or twinlead) it
is not a "Carolina Windom" and also not a "Windom".

I ran such an off-center-fed dipole 57 years ago
at Texas A&M fed with 300 ohm twinlead and a 6:1
Heathkit balun at the DX-40. It worked very well.


Hi Cecil,

Thanks for that report.
Amazing how many different views there are of the Windom.

According to one source (K4IWL, Carlson):

Original Windom is a single wire feed OCF dipole

Carolina Windom is a twin lead OCF dipole with balun below the twin lead
segment

New Carolina Windom is a OCF dipole to a 4:1 balun and a short coax
length followed by a 1:1 unun (choke)

Each using a .378/.622 OCF feedpoint.

I think I'll just call mine the Wiener Dipole and be done with it

John
AB8O


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Old September 11th 08, 07:58 AM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

On Wed, 10 Sep 2008 21:05:09 -0400, jawod wrote:

Gee, I think I follow, professor. Do tell.
73

John
AB8O


Hi John,

This (attached) should give you some sense of the rich variation of
matching opportunities for the same length of wire under variations of
tapping it with a drivepoint. The complexity of that data eludes
simple discussion.

73's
Richard Clark, KB7QHC
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Old September 11th 08, 12:25 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

jawod wrote:
Original Windom is a single wire feed OCF dipole


A "dipole" is usually two wires with an insulator between
them. The original Windom was a single wire fed with a
single wire against ground. It's radiation was primarily
vertically polarized. The horizontal wire acted more like
a top hat than a dipole.

Carolina Windom is a twin lead OCF dipole with balun below the twin lead
segment


This is one I was ignorant of - sorry.

New Carolina Windom is a OCF dipole to a 4:1 balun and a short coax
length followed by a 1:1 unun (choke)


I didn't know the present one is a "New" one. My
apologies for my ignorance of the Carolina Windom
history.

P.S. IMO, they should not have called it a "Windom".
--
73, Cecil http://www.w5dxp.com
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Old September 11th 08, 02:32 PM posted to rec.radio.amateur.antenna
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Default Carolina Windom using 300 ohm ladderline

Richard Clark wrote:
On Wed, 10 Sep 2008 21:05:09 -0400, jawod wrote:


Gee, I think I follow, professor. Do tell.
73

John
AB8O



Hi John,

This (attached) should give you some sense of the rich variation of
matching opportunities for the same length of wire under variations of
tapping it with a drivepoint. The complexity of that data eludes
simple discussion.

73's
Richard Clark, KB7QHC


Thanks for your help Richard. Always enjoy your posts.
BTW this one had no attachments (on my end anyway )

73

John
AB8O
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