Roy Lewallen wrote in
:

....
-- Be careful with the English language, in which fat chance and slim
chance mean the same thing, a wise man is admired and wise guy
shunned, and a bag lady and bag man are very different in ways other
than just their gender.

Ah yes, one's nose runs, and feet smell!

Owen

lu6etj wrote in
:

....
is very strict with wording and precision of terms :) then I thought
it was no exaggeration from me ask whether it is correct use the term
"balun" when both sides are "un", hi hi.

Perhaps the term 'common mode choke' works?

I did see a raging argument someone online (eham?) just recently where
parties were arguing that a 4:1 Guanella current balun could be wound on
a single toroid, it was the way Guanella intended it they said, but they
argued that use of two ferrite sticks for such a device was wrong.

In fact, Guanella's article describes his 1:1 balun without any magnetic
core material, and the 4:1 balun as a connected pair of 1:1 baluns with
no (ie negligible) magnetic coupling. Yet I have seen commercial sites
selling a Guanella 4:1 current balun on a single core, arguing that
Sevick said it was ok in a certain context... a context that is unlikely
to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they
sell. That context relates to another dimension of the balanced /
symmetric issue.

Back to the Carolina Windom, a common explanation holds that there is
common mode current on the feedline between the dipole feedpoint and the
'isolator'. The notion that common mode current exists on one side of the
isolator and not on the other is an interesting one, one better explained
by advertising hyperbole than radiocommunications theory.

Owen

On 9/12/2010 7:50 PM, Owen Duffy wrote:
... Yet I have seen commercial sites
selling a Guanella 4:1 current balun on a single core, arguing that
Sevick said it was ok in a certain context... a context that is unlikely
to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they
sell. That context relates to another dimension of the balanced /
symmetric issue.

Back to the Carolina Windom, a common explanation holds that there is
common mode current on the feedline between the dipole feedpoint and the
'isolator'. The notion that common mode current exists on one side of the
isolator and not on the other is an interesting one, one better explained
by advertising hyperbole than radiocommunications theory.

Owen

The first part, above, implies that no one has ever constructed such a
balun(s), one on a single core, one on a dual core, used "balanced"
resistances, to serve as loads, then unbalance the loads, and observe
results. I have, when constructed properly, one can be constructed on a
single core. Is the dual core better? Yes ... is it possible to run
the single core balun in conditions where it will fail miserably?; Yes.
Is it possible to run the dual core balun in conditions where it will
fail miserably?; Yes.

As to the second part, I have found a properly constructed balun to be
both, a choke and "impedance-transformer." Indeed, an excellent balun
is optimized to take advantage of both phenomenon.

And, of course, I have found and believe a 160m to 10m balun/unun is
stretching things, probably beyond what one should (but, hey, you can
get by with it), two baluns, a high freq and a low freq are better to
cover such a span ... however, you can carry that to an extreme and
optimize core material/size and windings for each specific band ...

And, radio is an onion, each layer built on a preceding layer. At the
core of all this is the EM transmission theory, and RF is both particles
and waves ... obviously, both have great difficulty being true at the
same time, so "waves of bullets" becomes the explanation ... obviously,
great difficulty is going to be had in having cement solid theory in the
outer layers of this onion. By the time you get to "balance" the errors
are only magnified ... balance is like any balance in life ... you'll
know it when you have it, and benefit from it.

Regards,
JS

On 12 sep, 23:35, Owen Duffy wrote:
Roy Lewallen wrote :

...

-- Be careful with the English language, in which fat chance and slim
chance mean the same thing, a wise man is admired and wise guy
shunned, and a bag lady and bag man are very different in ways other
than just their gender.

Ah yes, one's nose runs, and feet smell!

Owen

I agree with you Roy in several items, when we try communicate with
words and we not share the exact word meanings we end up inmersed in
the Babel course. Moreover, we later build bigger ideas based in that
misunderstood words, then it is not rare that at the end of the
process we can not agree almost nothing.

But there is a problem, explain our concepts writing in a paper it it
is not ease too, any dictionary it is circular referenced, verbal or
written definitions use words, then such circularity it is inherente
to written language in some point we will need to point to an object,
event or phenomenom and say to our partner: you see "this is a house",
"that is a river". That way we learn languages when we born, linguists
call them "ostensive definitions".

Because that, I pointed -in early post- we could end up having to
define all words we use. Here we call that process "socratic tests",
because a teacher could ask and ask definitions recursively to the
extent we were not able to explain even what is a mom.
Also, in some point we need support us in standard accepted
definitions of terms with its limitations at risk of failing to have a
common language, often authoritative definitions serve to this pupose
even although they are incomplete.

I do not would say I hate to waste my time arguing about apparently
senseless things because what to me may seems nonsense can be really
important and I am not capable to see it, but I agree that comes a
point where I tired and renounce (and there are much things that are
really suspiciously foolish). However I recognize that drop the bone
too early sometimes not conducive to resolving difficult issues, it is
all a matter of "balancing" :)

Thank you very much.

Miguel

PD: Nice examples of english meanings, when we tell: "ese es un hijo
de su madre" we are not talking about kinship relationships :)

On Sep 12, 9:50*pm, Owen Duffy wrote:
Back to the Carolina Windom, a common explanation holds that there is
common mode current on the feedline between the dipole feedpoint and the
'isolator'. The notion that common mode current exists on one side of the
isolator and not on the other is an interesting one, one better explained
by advertising hyperbole than radiocommunications theory.

As you know, common-mode RF obeys the rules of the reflection model.
From an (ideal) physics standpoint, there is nothing technically wrong
with having zero common mode current between the isolator and the
source while having a common mode current maximum (loop) 1/4WL back
toward the antenna feedpoint from the isolator. (Assume an ideal
isolator with an infinite choking impedance.)

Consider the following example:

Source--------1/2WL coax1--------isolator-------1/2WL coax2----------
antenna feedpoint

The net common-mode current on each side of the (ideal lumped)
isolator must be equal to satisfy Kirchhoff. There is no technical
reason why the net standing-wave common-mode current could not be zero
on each side of the isolator where the isolator is causing a standing-
wave current node (minimum). 1/4WL back from the isolator toward the
source, there is no technical reason why the net standing-wave common-
mode current could not be zero. 1/4WL forward from the isolator toward
the antenna, there is no technical reason why the net standing-wave
common-mode current could not be at a high (maximum-loop) value. Since
it is theoretically possible, one should not dismiss it as
"advertising hyperbole" without having performed the measurements to
prove that particular statement applies to the Carolina Windom because
of poor isolator performance, not because it violates Kirchhoff's
laws.

Incidentally, this is the same conceptual error that some folks have
made when they reported measuring no phase shift in the current
through a large air-core 75m loading coil when installed on a standing-
wave antenna. Hint: Pure standing wave current has zero relative phase
shift so it obviously cannot be used to measure phase shift. EZNEC
confirms that fact.
--
73, Cecil, w5dxp.com

On 9/13/2010 4:39 AM, Cecil Moore wrote:
... "Unun" is not in "The IEEE Dictionary".
--
73, Cecil, w5dxp.com

Yeah, those fools haven't plagiarized someone else yet, without giving
that someone else credit, give them time ...

Regards,
JS

On 9/12/2010 8:59 PM, John Smith wrote:
On 9/12/2010 7:50 PM, Owen Duffy wrote:
... Yet I have seen commercial sites
selling a Guanella 4:1 current balun on a single core, arguing that
Sevick said it was ok in a certain context... a context that is unlikely
to ever exist in an antenna system. But hey, Sevick is Mr Baluns, so they
sell. That context relates to another dimension of the balanced /
symmetric issue.
...
Owen

The first part, above, implies that no one has ever constructed such a
balun(s), one on a single core, one on a dual core, used "balanced"
resistances, to serve as loads, then unbalance the loads, and observe
results. I have, when constructed properly, one can be constructed on a
single core. Is the dual core better? Yes ... is it possible to run the
single core balun in conditions where it will fail miserably?; Yes. Is
it possible to run the dual core balun in conditions where it will fail
miserably?; Yes.

As to the second part, I have found a properly constructed balun to be
both, a choke and "impedance-transformer." Indeed, an excellent balun is
optimized to take advantage of both phenomenon.
...

Regards,
JS

This:
http://www.pdftop.com/view/aHR0cDovL...8xQmFsdW4ucGRm

is actually a pretty fair appraisal of it all ... beware line wrapping.

Regards,
JS

On 9/13/2010 1:22 PM, John Smith wrote:
On 9/13/2010 1:17 PM, John Smith wrote:

...
You might want to note that to Trask, he thinks it IS a current balun
... since it has the appearance of two 1:1 current baluns used on a
single core, I tend to agree with his take on it.

Regards,
JS

This core contains four windings, two on each side, they ARE wound to be
two 1:1 current (guanella baluns.) The phase of one winding on the
floating side is reversed, resulting in balun voltage being additive for
that floating winding, alone.

Regards,
JS

I should note, this is NOT misleading, the terminology clearly defines
this balun as a "HYBRID" balun.

Regards,
JS

Owen Duffy wrote in
:

Roy Lewallen wrote in
:


The key to the answer is in two words in the first sentence of your
posting: "immediately adjacent". You're certainly correct that the
current can't abruptly drop to zero at the terminator, because of
Kirchoff's Current Law. But the current doesn't abruptly end, rather
it drops to zero following a sinusoidal distribution curve. It's
quite

My modelling experience is that other things like connection to
ground, and open ends to conductors have more influence on the
location of a standing wave pattern than typical common mode chokes.

I have created a simple model of a Carolina Windom at 7MHz, assuming
that the device at the dipole feedpoint is a 4:1 voltage balun with
negligible common mode impedance, the isolater is 1000+j0 (your
nomination), and a feedline configuration that demonstrates that the
isolator has not caused a minimum in the common mode standing wave
pattern at that point.

A pic of the current distribution is at
http://www.vk1od.net/lost/Clip043.png .
...

Common mode chokes can be made pretty easily to have an impedance of
more than 1k ohm. Both modeling and measurement show this is usually
adequate in typical installations to drop common mode current to very
near zero at the choke location. But you can easily have substantial
current a quarter wavelength on either side of it.

Didn't work for this case, the current minimum is about half wave
between the isolator (left hand blue square) and the dipole, and the
common current entering the shack (right hand blue square) is quite
large.

Apologies, there was an error in the model... I hadn't installed the
source properly. I have replaced the pic at
http://www.vk1od.net/lost/Clip043.png . The situation is a little
different, but the isolator does not force a current minimim at its
location, and the common mode current flowing at the shack is large.

Owen

Owen Duffy wrote in news:Xns9DF34D79C6188nonenowhere@
61.9.134.55:

....
source properly. I have replaced the pic at
http://www.vk1od.net/lost/Clip043.png . The situation is a little

I have renamed it so that you get the new pic...
http://www.vk1od.net/lost/Clip043.png