On Mon, 27 Jun 2005 15:13:05 GMT, "Chris Trask"
wrote:

Whoa, let's reign back here a bit. The test was still for a 200-ohm
load, but it was made asymmetric (150-ohms and 50-ohms) in order to
accomodate the 50-ohm network analyzer.

Hi Chris,

You state you have several of these units, performing back-to-back
applications would resolve what you call asymmetry.

The 6dB loss is a result of the

Where did the 6dB come from? I didn't notice this mentioned anywhere.

Further, there is a strong 2dB/Octave frequency characteristic that is
not explained as an issue of symmetry.

voltage at the test port being Vin/2, but the voltage at the other output
port with the 150-ohm resistor is 3Vin/2, so there is no excessive loss
through the balun.

I don't know where this Vin/2 comes from. What is this divisor you've
injected into the discussion? As you offer it has no obvious
correlation to frequency, it stands that that same 2dB/Octave roll-off
is part and parcel to the unit's loss.

In actuality, there is less than 0.1dB of power loss in
the prototype that I made.

No where in your paper do you show the method to determine this, nor
do you reveal such a figure.

The test was made to determine if the balance
was correct.

The word "balance" occurs only once in your paper, and that as an
unsupported declaration. I see no work nor data to offer it as a
conclusion.

73's
Richard Clark, KB7QHC

On Mon, 27 Jun 2005 15:05:18 GMT, "Chris Trask"
wrote:

how is it that the ferrite makes the line appear longer?
The ferrite makes the line look longer by way of it's permeability

Hi Chris,

Conventionally, this is not an asset of BalUns. In fact, employing
permeability risks saturation, and saturation risks catastrophic
failure.

The paragraphs that followed (not quoted here) relate to the operation
of a conventional transformer.

Second, if this were to occur (through the design of a "transmission
line transformer" that was a voltage BalUn); what is the advantage of
longer lines?
It's a matter of what's practical.

Practical? This does not prove an advantage, it is a non-sequitur.

If you were to use very short lines
along with a high permeability material such as Fair-Rite 73, you may
encouter a region where the lines are too short to couple properly and the
magnetic material is well above the ferroresonance frequency. And even when
you do get into the flux-coupling môde, you still need to have sufficient
line in order to obtain decent coupling at lower frequencies. So, you have
to balance the two (line length and magnetic material) in order to obtain a
wideband transformer that has consistent performance over the desired
frequency range.

Most of this presumes a conventional transformer design. Your data
supports the results encountered from a conventional transformer
design. The risks of using a conventional transformer design are
legion. I see nothing that suggests this novel design is superior to
a Transmission Line Transformer (AKA Current BalUn).

73's
Richard Clark, KB7QHC

Chris Trask wrote:

1. That it is simply a 2:1 transformer with an isolated primary and
secondary?


No. It is a pair of 1:1 transformers on a single core. I can make it
work equally well by making the two transformers on separate cores. I can
also make it with a pair of equal length coaxial cables. Both of these
realisations defeat his claim that it is a 2:1 transformer.

If it were a mains or an audio transformer with four identical windings,
two primaries in parallel and two secondaries in series, most people
wouldn't hesitate to call that a "2:1" (voltage ratio) transformer. You
could also choose to call it "a pair of 1:1 transformers on a single
core" and that would also be valid, though I don't believe that would be
most people's preferred description.

The same output voltages can *also* be obtained by a different method,
by appropriately wiring two completely separate 1:1 transformers, but
that doesn't affect the way we should think about the transformer on a
single core.


But at the same
time, neither of them answer his claim that it is impossible to make a 4:1
current balun on a single core with a pair of 1:1 transformers.

Agreed.



2. That it is not a true transmission line transformer, because your
transmission-line windings are not being fed with opposite polarities
across the *same* end?


This isn't even a gray area. We're making a BALUN, in other words a
transformer that has an UNbalanced port and a BALanced port, and in this
case fully meeting the definition of a current balun. If we were to accept
the above statement, then we would have no choice except to conclude that in
no circumstances could we make a BALUN with transmission line transformers
because in all cases of BALUNs one port is fed unbalanced.

I was talking about TLT's, not baluns. Some baluns are TLT but others
are not.


Making transmission line transformers is not difficult, although Tom is
making it appear as though it's some sort of great mustery. For a length of
transmission line that is sufficiently short with respect to wavelength,
meaning less than an eighth of a wavelength in practice, the following rules
are observed:

1. The voltage across the one conductor is equal to the
voltage of the other conductor, both in magnitude and
in phase.

2. The current in the one conductor is equal in magnitude
but oppostite in phase to the current in the other
conductor.

These basic understandings of transmission line transformers are well
established and understood. Gary Breed brought the concept down to the
essentials in:

Breed, Gary, "Transmission Line Transformer Basics," Applied
Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60.

It all comes down to a difference between what is known by way of
established theory and practice versus trying to convince people that
everything we know is wrong.


Sorry, but it all seems to come down to the definitions of "current
balun" and "transmission line transformer" that one chooses to adopt.
Rather than referencing those definitions, please can you quote them
here, in full?


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Ian:

Yes, you inject a VERY GOOD point here--I realize my "definitions" are a
bit blurry. And, indeed, scanning the internet suggests there are some
others out there suffering the same.

What can we all agree are proper definitions to balun, "rf transformer",
etc... I admit I have not ever set up a solid foundation of knowledge
here--just used ideas, plans, etc which others have made available...
and referred to them by the names given... this leaves me at a loss
while I investigate.

John

"Ian White GM3SEK" wrote in message
...
Chris Trask wrote:

1. That it is simply a 2:1 transformer with an isolated primary and
secondary?


No. It is a pair of 1:1 transformers on a single core. I can
make it
work equally well by making the two transformers on separate cores. I
can
also make it with a pair of equal length coaxial cables. Both of
these
realisations defeat his claim that it is a 2:1 transformer.

If it were a mains or an audio transformer with four identical
windings, two primaries in parallel and two secondaries in series,
most people wouldn't hesitate to call that a "2:1" (voltage ratio)
transformer. You could also choose to call it "a pair of 1:1
transformers on a single core" and that would also be valid, though I
don't believe that would be most people's preferred description.

The same output voltages can *also* be obtained by a different method,
by appropriately wiring two completely separate 1:1 transformers, but
that doesn't affect the way we should think about the transformer on a
single core.


But at the same
time, neither of them answer his claim that it is impossible to make a
4:1
current balun on a single core with a pair of 1:1 transformers.

Agreed.



2. That it is not a true transmission line transformer, because your
transmission-line windings are not being fed with opposite
polarities
across the *same* end?


This isn't even a gray area. We're making a BALUN, in other words
a
transformer that has an UNbalanced port and a BALanced port, and in
this
case fully meeting the definition of a current balun. If we were to
accept
the above statement, then we would have no choice except to conclude
that in
no circumstances could we make a BALUN with transmission line
transformers
because in all cases of BALUNs one port is fed unbalanced.

I was talking about TLT's, not baluns. Some baluns are TLT but others
are not.


Making transmission line transformers is not difficult, although
Tom is
making it appear as though it's some sort of great mustery. For a
length of
transmission line that is sufficiently short with respect to
wavelength,
meaning less than an eighth of a wavelength in practice, the following
rules
are observed:

1. The voltage across the one conductor is equal to the
voltage of the other conductor, both in magnitude and
in phase.

2. The current in the one conductor is equal in magnitude
but oppostite in phase to the current in the other
conductor.

These basic understandings of transmission line transformers are well
established and understood. Gary Breed brought the concept down to
the
essentials in:

Breed, Gary, "Transmission Line Transformer Basics," Applied
Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60.

It all comes down to a difference between what is known by way of
established theory and practice versus trying to convince people that
everything we know is wrong.


Sorry, but it all seems to come down to the definitions of "current
balun" and "transmission line transformer" that one chooses to adopt.
Rather than referencing those definitions, please can you quote them
here, in full?


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Ian:

Here is a rather good paper on TLT's, this should be a definition
acceptable to most...
http://www.highfrequencyelectronics....204_Sevick.pdf

John

"Ian White GM3SEK" wrote in message
...
Chris Trask wrote:

1. That it is simply a 2:1 transformer with an isolated primary and
secondary?


No. It is a pair of 1:1 transformers on a single core. I can
make it
work equally well by making the two transformers on separate cores. I
can
also make it with a pair of equal length coaxial cables. Both of
these
realisations defeat his claim that it is a 2:1 transformer.

If it were a mains or an audio transformer with four identical
windings, two primaries in parallel and two secondaries in series,
most people wouldn't hesitate to call that a "2:1" (voltage ratio)
transformer. You could also choose to call it "a pair of 1:1
transformers on a single core" and that would also be valid, though I
don't believe that would be most people's preferred description.

The same output voltages can *also* be obtained by a different method,
by appropriately wiring two completely separate 1:1 transformers, but
that doesn't affect the way we should think about the transformer on a
single core.


But at the same
time, neither of them answer his claim that it is impossible to make a
4:1
current balun on a single core with a pair of 1:1 transformers.

Agreed.



2. That it is not a true transmission line transformer, because your
transmission-line windings are not being fed with opposite
polarities
across the *same* end?


This isn't even a gray area. We're making a BALUN, in other words
a
transformer that has an UNbalanced port and a BALanced port, and in
this
case fully meeting the definition of a current balun. If we were to
accept
the above statement, then we would have no choice except to conclude
that in
no circumstances could we make a BALUN with transmission line
transformers
because in all cases of BALUNs one port is fed unbalanced.

I was talking about TLT's, not baluns. Some baluns are TLT but others
are not.


Making transmission line transformers is not difficult, although
Tom is
making it appear as though it's some sort of great mustery. For a
length of
transmission line that is sufficiently short with respect to
wavelength,
meaning less than an eighth of a wavelength in practice, the following
rules
are observed:

1. The voltage across the one conductor is equal to the
voltage of the other conductor, both in magnitude and
in phase.

2. The current in the one conductor is equal in magnitude
but oppostite in phase to the current in the other
conductor.

These basic understandings of transmission line transformers are well
established and understood. Gary Breed brought the concept down to
the
essentials in:

Breed, Gary, "Transmission Line Transformer Basics," Applied
Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60.

It all comes down to a difference between what is known by way of
established theory and practice versus trying to convince people that
everything we know is wrong.


Sorry, but it all seems to come down to the definitions of "current
balun" and "transmission line transformer" that one chooses to adopt.
Rather than referencing those definitions, please can you quote them
here, in full?


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Unfortunately, I don't have that edition.
Is it four windings?
1---/////////---2
3---/////////---4
5---/////////---6
7---/////////---8
with (1 to 5) and (3 to 7) as the unbalanced input,
(4 to 6) tied together, and (2) and (8) as the balanced
output?


Yes, but they are not windings. They are parallel conductors in pairs.
1 and 3 form one pair. 5 and 7 the other.

You can see a schematic at:

http://www.w8ji.com/balun_single_core_41_analysis.htm

under real transmisison line balun. Sevik proposes the winding can
share a common core.

73 Tom

The entire difference between Chris and I is in my opinion he built
what most of the world would call a transformer. There is no forced TEM
mode excitation that I can see.

Sevik clearly drew a pair of transmission lines, and that was what I
was discussing (and I even exempted a primary/secondary transformer.

If I take a true transmission line choke balun and remove the core,
electrical line length does not change significantly. Chris in an
earlier post claimed the core lengthened the electrical "line length".

Also I'm assuming he didn't use 100 ohm lines, as a TL 4:1 balun
requires. He used coax, which as far as I know isn't easy to make at
100 ohms.

The limited SWR BW, the fact the core affects the electrical length of
the "lines", the high loss (.1dB), the fact the lines don't need to be
100 ohm lines, the lack of differential mode excitaion of the
start.....all point to operation like any other interleaved winding
transformer including audio and some power transformers.

I don't think an isolation transformer is "new art", but calling it a
transmission line transformer might be new! ;-)

73 Tom

However, with no electrical connection (transmission line) existing
between primary/secondary, and the voltage and current only conducted
between these windings by a magnetic flux--I CAN'T see how a "true"
balun can be argued, clearly--as opposed to "rf transformer."


I left out the word "current". My balun is a proper current balun as it
meets the formal definition, which is that it maintains currents at the
output terminals that are equal in magnitude and opposite in phase
regardless of potentials at the output terminals with respect to the ground
connection on the unbalanced side. You can find this definition in less
strict form in the ARRL handbook, such as 1991 pages 16.8-16.9.

The single core Guanella 4:1 current balun meets this definition but
only for floating loads. Anything other than that and the two transformers
need to be on separate cores.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_ |/ Principal Engineer
oo\ Sonoran Radio Research
(__)\ _ P.O. Box 25240
\ \ .' `. Tempe, Arizona 85285-5240
\ \ / \
\ '" \ IEEE Senior Member #40274515
. ( ) \
'-| )__| :. \ Email:
| | | | \ '. http://www.home.earthlink.net/~christrask
c__; c__; '-..'.__

Graphics by Loek Frederiks

"John Smith" wrote in message
...
Chris:

Well, I certainly can see that your claim it is two 1:1 baluns on a
single core is technically accurate--the primaries are in parallel and
their secondaries are in series... that seems clear enough that it
cannot be argued. I can't imagine all NOT to be in agreement on this
point.

However, with no electrical connection (transmission line) existing
between primary/secondary, and the voltage and current only conducted
between these windings by a magnetic flux--I CAN'T see how a "true"
balun can be argued, clearly--as opposed to "rf transformer."

But, I am giving this thought--as I am sure are others... I never
thought about the humble "balun"/"rf transformer" in some of these ways
before--possibly I am not alone... either and anyway, I enjoy the
thinking you have established here...

John

"Chris Trask" wrote in message
link.net...

1. That it is simply a 2:1 transformer with an isolated primary and
secondary?


No. It is a pair of 1:1 transformers on a single core. I can make
it
work equally well by making the two transformers on separate cores. I
can
also make it with a pair of equal length coaxial cables. Both of
these
realisations defeat his claim that it is a 2:1 transformer. But at
the same
time, neither of them answer his claim that it is impossible to make a
4:1
current balun on a single core with a pair of 1:1 transformers.


2. That it is not a true transmission line transformer, because your
transmission-line windings are not being fed with opposite polarities
across the *same* end?


This isn't even a gray area. We're making a BALUN, in other words
a
transformer that has an UNbalanced port and a BALanced port, and in
this
case fully meeting the definition of a current balun. If we were to
accept
the above statement, then we would have no choice except to conclude
that in
no circumstances could we make a BALUN with transmission line
transformers
because in all cases of BALUNs one port is fed unbalanced.

Making transmission line transformers is not difficult, although
Tom is
making it appear as though it's some sort of great mustery. For a
length of
transmission line that is sufficiently short with respect to
wavelength,
meaning less than an eighth of a wavelength in practice, the following
rules
are observed:

1. The voltage across the one conductor is equal to the
voltage of the other conductor, both in magnitude and
in phase.

2. The current in the one conductor is equal in magnitude
but oppostite in phase to the current in the other
conductor.

These basic understandings of transmission line transformers are well
established and understood. Gary Breed brought the concept down to
the
essentials in:

Breed, Gary, "Transmission Line Transformer Basics," Applied
Microwave & Wireless, Vol. 10, No. 4, May 1998, p. 60.

It all comes down to a difference between what is known by way of
established theory and practice versus trying to convince people that
everything we know is wrong.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_ |/ Principal Engineer
oo\ Sonoran Radio Research
(__)\ _ P.O. Box 25240
\ \ .' `. Tempe, Arizona 85285-5240
\ \ / \
\ '" \ IEEE Senior Member #40274515
. ( ) \
'-| )__| :. \ Email:
| | | | \ '. http://www.home.earthlink.net/~christrask
c__; c__; '-..'.__

Graphics by Loek Frederiks

"Ian White GM3SEK" wrote in message
...
Chris Trask wrote:

It's not a matter of whether I disagree with him or not. It's a
matter
of him standing on a cybersoapbox and declaring to the world in
numerous
ways that such a thing cannot work and that only his analysis of how
it
can
and cannot work is valid. He can't deny that he claimed that it was
impossible, so now he has to prove that the solution cannot possibly
work
the way that he knows that it cannot work. Whatever.


Please skip the personal rhetoric, and tell us how you respond to his
two main technical points about your transformer:

1. That it is simply a 2:1 transformer with an isolated primary and
secondary?

2. That it is not a true transmission line transformer, because your
transmission-line windings are not being fed with opposite polarities
across the *same* end?


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

I left out the word "current". My balun is a proper current balun as
it
meets the formal definition, which is that it maintains currents at the

output terminals that are equal in magnitude and opposite in phase
regardless of potentials at the output terminals with respect to the
ground
connection on the unbalanced side. You can find this definition in
less
strict form in the ARRL handbook, such as 1991 pages 16.8-16.9.

I agree.It just isn't a transmission line balun, nor an optimum design
for most applications.

The single core Guanella 4:1 current balun meets this definition
but
only for floating loads. Anything other than that and the two
transformers
need to be on separate cores.

I agree again. That's what I've been saying all along.

There we have it. Problem solved except for calling transmission lines
transformers, and transformers transmission lines.

73 Tom

However, with no electrical connection (transmission line) existing
between primary/secondary, and the voltage and current only conducted
between these windings by a magnetic flux--I CAN'T see how a "true"
balun can be argued, clearly--as opposed to "rf transformer."


But, I am giving this thought--as I am sure are others... I never
thought about the humble "balun"/"rf transformer" in some of these ways

before--possibly I am not alone... either and anyway, I enjoy the
thinking you have established here...

Aw comen on now John. Every single link coupled transformer from the
1900's to today works on the principle, as do link coupled tuners or
matching systems.

Many solid state amplifiers, as amatter of fact MOST HF solid state
amps use a primary/secondary transformer to couple unbalanced loads to
the PA transistors balanced source.

As a matter of fact many use a similar circuit as this "novel
invention". The ALM-500 for example used series secondarys for a period
of time, as did Henry amps.

I had a push-pull 810 amplifier that used the same system to drive the
grids of the triodes in 1964 or 65.

Using a transformer with interleaved or coaxial windings is about as
new as the first power transmission with AC power.

The only thing new or novel about Chris' "invention" is he has
redefined transmission line to include flux-coupled windings that do
not convey energy via TEM (transverse electiomagnetic) waves like the
normal transmission line we use.

Making up a new definition is not the same as producing a new or novel
invention. This is almost like the new invention call Fractal antennas
or E-H antennas that don't use "old" technology!

73 Tom