On Sep 1, 3:31*pm, Cecil Moore wrote:
wrote:
A common mode choke is used in RF applications, very true, but it
serves a filtering purpose, not a conversion of unbalanced to
balanced energy transfer or vice
versa. A common mode choke that operates well will turn
unwanted RF into heat or cause it to dissipate in its core or a
resistor etc..

The common "W2DU balun" works well as both choke and
balun function.
--
73, Cecil *http://www.w5dxp.com

Yes and I have to partially take back what I said; a balun CAN double
as a CM "choke" and a CM choke can double as a balun. If
one wishes to balance an unbalanced line with a CM choke, then the
impedance of the CM choke must match the source and the load, which
makes the CM choke a balun and no longer a choke :-)

wrote:

...
Yes and I have to partially take back what I said; a balun CAN double
as a CM "choke" and a CM choke can double as a balun. If
one wishes to balance an unbalanced line with a CM choke, then the
impedance of the CM choke must match the source and the load, which
makes the CM choke a balun and no longer a choke :-)



Although this URL:

http://www.radioelectronicschool.net.../ocfdipole.pdf

deals with a Windom Antenna, his text on the design, construction,
function and implementation of baluns is well worth the read.

Regards,
JS

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

...
Yes and I have to partially take back what I said; a balun CAN double
as a CM "choke" and a CM choke can double as a balun. If
one wishes to balance an unbalanced line with a CM choke, then the
impedance of the CM choke must match the source and the load, which
makes the CM choke a balun and no longer a choke :-)



Although this URL:

http://www.radioelectronicschool.net.../ocfdipole.pdf

deals with a Windom Antenna, his text on the design, construction,
function and implementation of baluns is well worth the read.

Regards,
JS

It's a trivial point, I agree, but there is one error in the url JS provided
above that needs correcting. The VK author tells us that the Windom antenna was
invented by Loren G. Windom. Tain't so. It was invented (developed) by William
Everitt, then the Dean of the EE Dept at Ohio State U. Everitt was doing the
grunt work and taking measurements along with another OSU professor. However.
Loren Windom was a student of Everitt's, and was tagging along and observing.
Then, later on he wrote up the experiment and had it published in QST sometime
in 1929, and as well as I can remember, he failed to give Everitt any credit for
having done the actual work. Consequently, readers of QST assumed it was
Windom's invention, while it actually was not.

Walt, W2DU

Walter Maxwell wrote:

...
It's a trivial point, I agree, but there is one error in the url JS provided
above that needs correcting. The VK author tells us that the Windom antenna was
invented by Loren G. Windom. Tain't so. It was invented (developed) by William
Everitt, then the Dean of the EE Dept at Ohio State U. Everitt was doing the
grunt work and taking measurements along with another OSU professor. However.
Loren Windom was a student of Everitt's, and was tagging along and observing.
Then, later on he wrote up the experiment and had it published in QST sometime
in 1929, and as well as I can remember, he failed to give Everitt any credit for
having done the actual work. Consequently, readers of QST assumed it was
Windom's invention, while it actually was not.

Walt, W2DU



Walter:

Thank you for that clarification, it was also interesting and
enlightening--I was ignorant to that info.

Warm regards,
JS

"John Smith" wrote in message
...
Walter Maxwell wrote:

...
It's a trivial point, I agree, but there is one error in the url JS provided
above that needs correcting. The VK author tells us that the Windom antenna
was
invented by Loren G. Windom. Tain't so. It was invented (developed) by
William
Everitt, then the Dean of the EE Dept at Ohio State U. Everitt was doing the
grunt work and taking measurements along with another OSU professor.
However.
Loren Windom was a student of Everitt's, and was tagging along and
observing.
Then, later on he wrote up the experiment and had it published in QST
sometime
in 1929, and as well as I can remember, he failed to give Everitt any credit
for
having done the actual work. Consequently, readers of QST assumed it was
Windom's invention, while it actually was not.

Walt, W2DU



Walter:

Thank you for that clarification, it was also interesting and
enlightening--I was ignorant to that info.

Warm regards,
JS

Hi John, glad I could make that microcontribution.

Walt

"Walter Maxwell" wrote in
:


"John Smith" wrote in message
...
wrote:
....
deals with a Windom Antenna, his text on the design, construction,
function and implementation of baluns is well worth the read.

Doesn't that article espouse the Guanella 4:1 current balun built on a
single toroid?

The extent to which such a construction works is due to flux leakage,
rather than the principles described by Guanella.

Owen

Owen Duffy wrote:
"Walter Maxwell" wrote in
:

"John Smith" wrote in message
...
wrote:
...
deals with a Windom Antenna, his text on the design, construction,
function and implementation of baluns is well worth the read.

Doesn't that article espouse the Guanella 4:1 current balun built on a
single toroid?

The extent to which such a construction works is due to flux leakage,
rather than the principles described by Guanella.

Owen

Owen:

You might have missed this part from the Windom URL:

"As far as the forward power to the antenna is
concerned there is no ferrite core. This is
because we have transmission “through two
transmission lines”. There is no external flux
around transmission lines. However if the
antenna is unbalanced there will be leakage or
common mode current flow through the
balun. These currents are not transmission line
mode currents. These currents will see a
choking reactance presented by the balun and
be stopped or significantly reduced. These
leakage currents if extremely excessive can
cause heating of the balun (but you have
probably got a serious problem that you need
to fix). Very high SWR can cause voltage
dielectric loss and even flashover between the
windings. Again this would indicate a more
serious problem with the antenna."

I should think a single core would be superior in relation to the above
stated phenomenon. Indeed, I suspect it to be preferable to two cores.
However, if such "leakage" is occuring, the author indicates you have
a problem with the antenna proper which needs a fix ...

However, this URL:

http://www.n0ss.net/qrp_4-1_guanella-type_balun.pdf

in the include pick 4-1_schematic.jpg, in the URL, contains a "blurb" on
how to move a single core design on to two cores.

Regards,
JS

John Smith wrote:

However, this URL:

http://www.n0ss.net/qrp_4-1_guanella-type_balun.pdf

in the include pick 4-1_schematic.jpg, in the URL, contains a "blurb" on
how to move a single core design on to two cores.

Did you mean a two core design onto one core?

Here is an analysis of the single core version:
http://www.vk1od.net/balun/gsc/index.htm .

Guanella did not show the 4:1 balun on a shared magnetic circuit, and it
is an error on the part of those who think that the two independent TLTs
in Guanella's circuit can be coupled without changing the behaviour
significantly (basically, ruining it).

Owen

Owen wrote:

...
Did you mean a two core design onto one core?

Here is an analysis of the single core version:
http://www.vk1od.net/balun/gsc/index.htm .

Guanella did not show the 4:1 balun on a shared magnetic circuit, and it
is an error on the part of those who think that the two independent TLTs
in Guanella's circuit can be coupled without changing the behaviour
significantly (basically, ruining it).

Owen

Let's cut the crap, currents in one winding which cause lines of force
in the toroid/ferrite-core, should only assist the lines of force
generated in the core by the other winding on the opposite side of the
core--in the single core model of the guanella balun--composed of two
1:1s in a 1:4 configuration (or guanella TLT, since you seem to prefer
acronyms.) At least TLT get the transmission line requirement out in
the open ...

Since toroids naturally demonstrate "economy of loss" in the magnetic
lines of force within their structure, few, if any, lines of force would
be shared between two separate cores, stacked.

Now, wasn't it Einstein who recommended that things only be made as
complex as necessary and not one iota more?--Or, watch out for the gray
haired man who keeps attempting to sneak behind the curtains in this
train ride though Oz--and KEEP HIM AWAY FROM THE LEVERS! ;-P

Regards,
JS

--
It is like a nightmare where the public servants are the people which
the police are supposed to protect us from!

Owen Duffy wrote:
"Walter Maxwell" wrote in
:

"John Smith" wrote in message
...
wrote:
...
deals with a Windom Antenna, his text on the design, construction,
function and implementation of baluns is well worth the read.

Doesn't that article espouse the Guanella 4:1 current balun built on a
single toroid?

The extent to which such a construction works is due to flux leakage,
rather than the principles described by Guanella.

Owen

Here is an article which includes text on the use of ferrite rods in
place of toroids.

Someone who has a couple of rods from some old am radios, etc. may
already have the stuff in his junk box to throw together an introductory
prototype?

Regards,
JS