开云体育

Yes, they are used to clip their toenails. The Frankenstock guys were too hard to remember so they narrowed the snoot and called them gators and for the most part they held better..... IMO.

John
KK4ITX

Visit: www.zaarc.org. ?

Are they used to clip alligators? :)

(Thou shalt not take thyself too seriously!)

I have lived in Florida for 20+ years....... believe me they are ALLIGATOR CLIPS if I ever saw one !

John
KK4ITX

Visit: www.zaarc.org. ?

You mean one like this:



Small Fahnestock Clip


Fahnestock clip top viewFahnestock clip top viewFahnestock clip top view

Mike C. Sand Mtn GA

On Sun, Mar 12, 2023 at 03:49 PM, WB2UAQ wrote:

If you are measuring baluns and large components like this below 30 MHz you
surely can get away with a lot. I guess when you run into situations at
higher frequencies you can over do it a bit for these large very widely
varying components. As others above soldering these to BNC's or SMA's should
be fine but still not alligator clips:) 73, Pete

Once you get above a few MHz. you have to be careful when measuring capacitors, inductors and baluns if you want meaningful results. Stray inductance and capacitance can make a big difference and you can get resonance effects that are due to parasitics and not the component itself. Attached is one example where a few pF of stray capacitance from using an alligator clip test jig made an inductor look like it was resonant when this was not the case. Another shows how the value of a capacitor measurement is affected by an alligator clip test jig. Comparisons were made to a fixed jig using properly spaced SOL with 50 ohm SMD.

Well put! Yes, we've traveled into the gravitational warp of a neutron
star.

Dave - W?LEV

--
Dave - W?LEV

No longer exist?

We have gone down the rabbit hole. Fahnstock clips no longer exist, and effectively never existed! :-)

I’d say from the way the group io acted up, we’ve hit a point of local resonance and have driven the web j to the left hand plane of the Bode plot!

?

Can we go back to Fahnestock clips? :-\

73,
Gary - W6GVS

If you are measuring baluns and large components like this below 30 MHz you surely can get away with a lot. I guess when you run into situations at higher frequencies you can over do it a bit for these large very widely varying components. As others above soldering these to BNC's or SMA's should be fine but still not alligator clips:) 73, Pete

But the expression for voltage or current yields a bigger number. Everyone
knowns a bigger number is "better"......

Dave - W?LEV

--
Dave - W?LEV

Hello all of you,

Almost a year ago I asked if someone has done (or is able to do)
measurements of the same DUT with a 3-term (like NanoVNA) and a 12-term
calibration device (
).

I am still interested in such a comparison, to be sure on the accuracy (and
precision) of such results.

My results are here:

and the whole page is at:


So if you have done such a comparison or are willing to collaborate on
this, let me know. I am eager to help to do this. Thanks in advance.

All the best,

Victor

--
73 de PE1ATN or NL413

Again, remember, we are not dealing with metrology quality instruments.
They are certainly good enough for what we need. Well, maybe for tuning
repeater cans, we'd like 100 dB of on-screen dynamic range. But we are
dealing with very capable instruments that are quite economical - less than
$200. For those with deep pockets, spend some of your green backs on
Keysite, R&S, or Tek. You're looking at more that $15k.

20 LOG10[15000 / 200] = 37.5 dB

Get the point?

Dave - W?LEV

--
Dave - W?LEV

In the last email on the subject, please forgive me for being a bit
cryptic. I'm just so frustrated with what the "memorize and forget"
philosophy has gotten us in amateur radio in general. Yes, I know it's
become the standard to test well on the standardized tests (public
education), but it ain't git'n the job dun.

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:47?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

Where is the text that went with the attachments?????? Try again:

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:42?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

I hope they (Starlink) doesn't truncate this email, again......

Here it is again.........

QUOTE: " But I note that many “internet experts” I have read begin

their

reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑”

or

“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This

is

one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many

times

are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns)

is

one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our

output

devices and FETs in our modern amplifiers from reducing themselves back

to

their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it

makes a

really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek

write-up,

but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at

any

given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs

will

not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements??

The

measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss

measurements

using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even

do

simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency.

Of

course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the

seven

chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms

is

mostly on the bottom - inductive - side of the smith chart - also

included

in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out

around

0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven

which

I measured.

I'll also attach a measurement I made documenting the effect of the CMC

on

40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:21?PM David Eckhardt <davearea51a@...>
wrote:

Why was my email and the attachments theretoo truncated???????? The

whole

email is not present!!!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:14?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

QUOTE: " But I note that many “internet experts” I have read begin

their

reports or designs or whatever by stating or thinking they “have

别苍辞耻驳丑”

or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is

abs

Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing.

This

is

one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of

them

truly do not understand what they are attempting to present and many

times

are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT

baluns)

is
one of the most misunderstood and misrepresented aspects in amateur

radio

(and a few other online subjects as well). Most of my references

(yes,

hard bound thick books on the shelf right in front of me ) are

graduate

level texts. These are well above the understanding of likely 97% of

the

average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality.

"Don't

worry about how it works. Just take my word, it works.........."

This

grates me from the hair on my head to my big left foot toe nail!!!

Well,

enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our

output

devices and FETs in our modern amplifiers from reducing themselves

back

to

their original state: quartz or silicon dioxide. SiO2 is an

excellent

insulator and was (and still is) used in frequency control. But it

makes

a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek
write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to)

the

CMCs I have built. Those I presently have on the shelf to choose

from -

depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at

any

given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs
will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements??
The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss
measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which

the

average amateur has no basis in understanding the rank basics of

complex

impedances, the Smith Chart, return loss, and......... Most can't

even

do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of

frequency.

Of
course, all measurements are made in a rigorous 50-Ohm system. The

left

most column is frequency - the amateur bands. The following columns

are

the measured CMRRs for the various CMCs in dB as measured on a

calibrated

setup using the HP 8753C VNA. The second page presents a key to the

seven

chokes which I measured. The fallacy of these measurements is that

the

CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of

the

impedance presented by the CMC to the L-network for matching to

50-Ohms

is

mostly on the bottom - inductive - side of the smith chart - also

included

in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out

around

0.55 and the Zo was between 73 and 103-ohms (if I remember) -

calculated

from Zo = √[L/C]. I've also included a picture of one of the CMCs.

The

loss measurements all came out at or less than 0.6 dB over the seven

which

I measured.

I'll also attach a measurement I made documenting the effect of the

CMC

on

40-meters.

PLEASE: Others read as well. I've continued on the group.io instead

of

going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV



On Sun, Mar 12, 2023 at 4:51?PM AG6CX <edwmccann@...> wrote:

Dave -

One last question on your baluns and such
from my inquiry, item 5:

“5. Your observed results of Z CMC offered by each CMC choke ? In

form

Z=R

+jX and related Reflection Coefficient Gamma Vector = rho Angle

Gamma? Or

诲叠.”

Do you have plots of Z, X and R. Vs frequency of your chokes that

you

might share with us?

I’m interested in how much CMC impedance you think (or know) is

being

introduced by the chokes.

I note that many seminal descriptions of the balun issue begins with

the

colored charts of Steve Hunt, G3TXQ (sk), who opens with a

description

of

the impedance s frequency of various materials.



He concludes with a link describing how he measured, and another to

a

spreadsheet that converts the measurements to Z, R and X.

A pretty complete description.

Some have been unable to recreate the results, and gave offered

their

own

measurements, like Jeff Anderson K6JCA (google and ye shall find),

Jim

Brown K9YC, whose work we have discussed here, and others,

including

Owen

Duffy VK1OD and Tom Rauch W8JI.

But I note that many “internet experts” I have read begin their

reports

or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or

“蝉丑辞耻濒诲

be 别苍辞耻驳丑” common mode impedance without offering a single

measurement,

or

just thinking the impedance they are worried about is abs Zcmc, and

leave

it at that.

The website of DJ0IP you describe does the same thing. Not a

measurement

beyond SWR. For an estimate of how much impedance? Fall back on

厂迟别惫别’蝉

coloring book. While it is a collection of interesting bits and

pieces,

the

site is an aggregator of the works of others, but at least offers a

spot

for one-stop shopping. Adherence to the physics and science is not

quite as

strict as you maintain.

With regard to figure of merit, there is nothing wrong with looking

hard

at SWR. You will recall an article on searching too hard for the

last

bit

of SWR could be harmful to one’s health! I post an insightful link

to

Owen

Duffy regarding an obsession with chasing phase, but the phase of

what?

Impedance phase or of that presented by reliance on S11 phase, as

the

nifty

RigExpert analyzers present. And as many amateurs seem to confuse.




Again, thanks for your continued contributions to the field!

Looking forward to a description of how much CMC choking you have in

the

baluns installed when you get a minute.

73
Ed McCann
AG6CX

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*


--
Dave - W?LEV

Where is the text that went with the attachments?????? Try again:

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:42?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

I hope they (Starlink) doesn't truncate this email, again......

Here it is again.........

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:21?PM David Eckhardt <davearea51a@...>
wrote:

Why was my email and the attachments theretoo truncated???????? The

whole

email is not present!!!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:14?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

QUOTE: " But I note that many “internet experts” I have read begin

their

reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑”
or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is

abs

Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This

is

one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of

them

truly do not understand what they are attempting to present and many

times

are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns)
is
one of the most misunderstood and misrepresented aspects in amateur

radio

(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of

the

average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!!

Well,

enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our

output

devices and FETs in our modern amplifiers from reducing themselves back

to

their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it

makes

a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek
write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at

any

given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs
will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements??
The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss
measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which

the

average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even
do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency.
Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a

calibrated

setup using the HP 8753C VNA. The second page presents a key to the

seven

chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms

is

mostly on the bottom - inductive - side of the smith chart - also

included

in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out

around

0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven

which

I measured.

I'll also attach a measurement I made documenting the effect of the CMC

on

40-meters.

PLEASE: Others read as well. I've continued on the group.io instead

of

going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV



On Sun, Mar 12, 2023 at 4:51?PM AG6CX <edwmccann@...> wrote:

Dave -

One last question on your baluns and such
from my inquiry, item 5:

“5. Your observed results of Z CMC offered by each CMC choke ? In form

Z=R

+jX and related Reflection Coefficient Gamma Vector = rho Angle

Gamma? Or

诲叠.”

Do you have plots of Z, X and R. Vs frequency of your chokes that you
might share with us?

I’m interested in how much CMC impedance you think (or know) is being
introduced by the chokes.

I note that many seminal descriptions of the balun issue begins with

the

colored charts of Steve Hunt, G3TXQ (sk), who opens with a description

of

the impedance s frequency of various materials.



He concludes with a link describing how he measured, and another to a
spreadsheet that converts the measurements to Z, R and X.

A pretty complete description.

Some have been unable to recreate the results, and gave offered their

own

measurements, like Jeff Anderson K6JCA (google and ye shall find), Jim
Brown K9YC, whose work we have discussed here, and others, including

Owen

Duffy VK1OD and Tom Rauch W8JI.

But I note that many “internet experts” I have read begin their

reports

or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or

“蝉丑辞耻濒诲

be 别苍辞耻驳丑” common mode impedance without offering a single

measurement,

or

just thinking the impedance they are worried about is abs Zcmc, and

leave

it at that.

The website of DJ0IP you describe does the same thing. Not a

measurement

beyond SWR. For an estimate of how much impedance? Fall back on

厂迟别惫别’蝉

coloring book. While it is a collection of interesting bits and

pieces,

the

site is an aggregator of the works of others, but at least offers a

spot

for one-stop shopping. Adherence to the physics and science is not

quite as

strict as you maintain.

With regard to figure of merit, there is nothing wrong with looking

hard

at SWR. You will recall an article on searching too hard for the last

bit

of SWR could be harmful to one’s health! I post an insightful link to

Owen

Duffy regarding an obsession with chasing phase, but the phase of

what?

Impedance phase or of that presented by reliance on S11 phase, as the

nifty

RigExpert analyzers present. And as many amateurs seem to confuse.




Again, thanks for your continued contributions to the field!

Looking forward to a description of how much CMC choking you have in

the

baluns installed when you get a minute.

73
Ed McCann
AG6CX

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*


--
Dave - W?LEV

I hope they (Starlink) doesn't truncate this email, again......

Here it is again.........

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:21?PM David Eckhardt <davearea51a@...>
wrote:

Why was my email and the attachments theretoo truncated???????? The whole
email is not present!!!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:14?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑”
or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns)
is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes
a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek
write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs
will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements??
The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss
measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even
do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency.
Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV



On Sun, Mar 12, 2023 at 4:51?PM AG6CX <edwmccann@...> wrote:

Dave -

One last question on your baluns and such
from my inquiry, item 5:

“5. Your observed results of Z CMC offered by each CMC choke ? In form

Z=R

+jX and related Reflection Coefficient Gamma Vector = rho Angle

Gamma? Or

诲叠.”

Do you have plots of Z, X and R. Vs frequency of your chokes that you
might share with us?

I’m interested in how much CMC impedance you think (or know) is being
introduced by the chokes.

I note that many seminal descriptions of the balun issue begins with the
colored charts of Steve Hunt, G3TXQ (sk), who opens with a description

of

the impedance s frequency of various materials.



He concludes with a link describing how he measured, and another to a
spreadsheet that converts the measurements to Z, R and X.

A pretty complete description.

Some have been unable to recreate the results, and gave offered their

own

measurements, like Jeff Anderson K6JCA (google and ye shall find), Jim
Brown K9YC, whose work we have discussed here, and others, including

Owen

Duffy VK1OD and Tom Rauch W8JI.

But I note that many “internet experts” I have read begin their reports
or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or

“蝉丑辞耻濒诲

be 别苍辞耻驳丑” common mode impedance without offering a single measurement,

or

just thinking the impedance they are worried about is abs Zcmc, and

leave

it at that.

The website of DJ0IP you describe does the same thing. Not a measurement
beyond SWR. For an estimate of how much impedance? Fall back on 厂迟别惫别’蝉
coloring book. While it is a collection of interesting bits and pieces,

the

site is an aggregator of the works of others, but at least offers a spot
for one-stop shopping. Adherence to the physics and science is not

quite as

strict as you maintain.

With regard to figure of merit, there is nothing wrong with looking hard
at SWR. You will recall an article on searching too hard for the last

bit

of SWR could be harmful to one’s health! I post an insightful link to

Owen

Duffy regarding an obsession with chasing phase, but the phase of what?
Impedance phase or of that presented by reliance on S11 phase, as the

nifty

RigExpert analyzers present. And as many amateurs seem to confuse.




Again, thanks for your continued contributions to the field!

Looking forward to a description of how much CMC choking you have in the
baluns installed when you get a minute.

73
Ed McCann
AG6CX

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*

--
*Dave - W?LEV*


--
Dave - W?LEV

Why was my email and the attachments theretoo truncated???????? The whole
email is not present!!!!!!

Dave - W?LEV

On Sun, Mar 12, 2023 at 7:14?PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV



On Sun, Mar 12, 2023 at 4:51?PM AG6CX <edwmccann@...> wrote:

Dave -

One last question on your baluns and such
from my inquiry, item 5:

“5. Your observed results of Z CMC offered by each CMC choke ? In form

Z=R

+jX and related Reflection Coefficient Gamma Vector = rho Angle Gamma?

Or

诲叠.”

Do you have plots of Z, X and R. Vs frequency of your chokes that you
might share with us?

I’m interested in how much CMC impedance you think (or know) is being
introduced by the chokes.

I note that many seminal descriptions of the balun issue begins with the
colored charts of Steve Hunt, G3TXQ (sk), who opens with a description of
the impedance s frequency of various materials.



He concludes with a link describing how he measured, and another to a
spreadsheet that converts the measurements to Z, R and X.

A pretty complete description.

Some have been unable to recreate the results, and gave offered their own
measurements, like Jeff Anderson K6JCA (google and ye shall find), Jim
Brown K9YC, whose work we have discussed here, and others, including

Owen

Duffy VK1OD and Tom Rauch W8JI.

But I note that many “internet experts” I have read begin their reports
or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or

“蝉丑辞耻濒诲

be 别苍辞耻驳丑” common mode impedance without offering a single measurement,

or

just thinking the impedance they are worried about is abs Zcmc, and leave
it at that.

The website of DJ0IP you describe does the same thing. Not a measurement
beyond SWR. For an estimate of how much impedance? Fall back on 厂迟别惫别’蝉
coloring book. While it is a collection of interesting bits and pieces,

the

site is an aggregator of the works of others, but at least offers a spot
for one-stop shopping. Adherence to the physics and science is not quite

as

strict as you maintain.

With regard to figure of merit, there is nothing wrong with looking hard
at SWR. You will recall an article on searching too hard for the last bit
of SWR could be harmful to one’s health! I post an insightful link to

Owen

Duffy regarding an obsession with chasing phase, but the phase of what?
Impedance phase or of that presented by reliance on S11 phase, as the

nifty

RigExpert analyzers present. And as many amateurs seem to confuse.




Again, thanks for your continued contributions to the field!

Looking forward to a description of how much CMC choking you have in the
baluns installed when you get a minute.

73
Ed McCann
AG6CX

--
*Dave - W?LEV*


--
Dave - W?LEV

--
*Dave - W?LEV*


--
Dave - W?LEV

QUOTE: " But I note that many “internet experts” I have read begin their
reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or
“蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single
measurement, or just thinking the impedance they are worried about is abs
Zcmc, and leave it at that."

Yes, this is due to no real understanding of what they are doing. This is
one major reason I do not recommend consulting amateur YouTube
presentations. As I stated in my original (long....) reply, most of them
truly do not understand what they are attempting to present and many times
are in error.

For one thing, the whole subject of antennas and transmission lines,
including baluns and matching transformers (transformers are NOT baluns) is
one of the most misunderstood and misrepresented aspects in amateur radio
(and a few other online subjects as well). Most of my references (yes,
hard bound thick books on the shelf right in front of me ) are graduate
level texts. These are well above the understanding of likely 97% of the
average amateur in the US. I try my best *not* to present on the
technician level - "this is how you build the widget" mentality. "Don't
worry about how it works. Just take my word, it works.........." This
grates me from the hair on my head to my big left foot toe nail!!! Well,
enough of that rant.......

As far as SWR is concerned, it's important as insurance to keep our output
devices and FETs in our modern amplifiers from reducing themselves back to
their original state: quartz or silicon dioxide. SiO2 is an excellent
insulator and was (and still is) used in frequency control. But it makes a
really bad RF amplifier......!! Have a read of "SWR Meters Make You
Stupid" - attached. I know the author and it's a tongue-in-cheek write-up,
but excellent in content.

Yes, I have measured everything of interest w.r.t. (with respect to) the
CMCs I have built. Those I presently have on the shelf to choose from -
depending on frequency and the complex impedance my feedline/antenna
presents to them in the shack - I have built and measured at least 40
various incantations to come out with 7 on the shelf to choose from at any
given time . Again, there is "no size fits all". I have not to date
presented the results on this forum due to the fact that most amateurs will
not understand the measurements. If they don't understand complex
impedance and use only |Z|, how can they assimilate the measurements?? The
measurements were presented some two years ago on the NANOVNA group
including technician level "how to" make CMRR and through loss measurements
using the NANOVNAs. The procedures should be in the archives of that
group. I'm not going to waist my time explaining something for which the
average amateur has no basis in understanding the rank basics of complex
impedances, the Smith Chart, return loss, and......... Most can't even do
simple algebra (should have been engrained in HS).

As far as the CMRR of the various CMCs, please see the attachment for
measured CMRR values of seven of the chokes as a function of frequency. Of
course, all measurements are made in a rigorous 50-Ohm system. The left
most column is frequency - the amateur bands. The following columns are
the measured CMRRs for the various CMCs in dB as measured on a calibrated
setup using the HP 8753C VNA. The second page presents a key to the seven
chokes which I measured. The fallacy of these measurements is that the
CMRR reflects the choke embedded in a 50-Ohm system. The DM end
(windowline) of the choke is anything but 50-Ohms. Measurements of the
impedance presented by the CMC to the L-network for matching to 50-Ohms is
mostly on the bottom - inductive - side of the smith chart - also included
in the attachments.

I measured the Vp and Z only a few of the CMCs. The Vp's came out around
0.55 and the Zo was between 73 and 103-ohms (if I remember) - calculated
from Zo = √[L/C]. I've also included a picture of one of the CMCs. The
loss measurements all came out at or less than 0.6 dB over the seven which
I measured.

I'll also attach a measurement I made documenting the effect of the CMC on
40-meters.

PLEASE: Others read as well. I've continued on the group.io instead of
going private in the hope that others will also learn from reading.
Continuing to learn is the spice of life!!!!

Dave - W?LEV

--
Dave - W?LEV

Dave -

One last question on your baluns and such
from my inquiry, item 5:

“5. Your observed results of Z CMC offered by each CMC choke ? In form Z=R +jX and related Reflection Coefficient Gamma Vector = rho Angle Gamma? Or 诲叠.”

Do you have plots of Z, X and R. Vs frequency of your chokes that you might share with us?

I’m interested in how much CMC impedance you think (or know) is being introduced by the chokes.

I note that many seminal descriptions of the balun issue begins with the colored charts of Steve Hunt, G3TXQ (sk), who opens with a description of the impedance s frequency of various materials.



He concludes with a link describing how he measured, and another to a spreadsheet that converts the measurements to Z, R and X.

A pretty complete description.

Some have been unable to recreate the results, and gave offered their own measurements, like Jeff Anderson K6JCA (google and ye shall find), Jim Brown K9YC, whose work we have discussed here, and others, including Owen Duffy VK1OD and Tom Rauch W8JI.

But I note that many “internet experts” I have read begin their reports or designs or whatever by stating or thinking they “have 别苍辞耻驳丑” or “蝉丑辞耻濒诲 be 别苍辞耻驳丑” common mode impedance without offering a single measurement, or just thinking the impedance they are worried about is abs Zcmc, and leave it at that.

The website of DJ0IP you describe does the same thing. Not a measurement beyond SWR. For an estimate of how much impedance? Fall back on 厂迟别惫别’蝉 coloring book. While it is a collection of interesting bits and pieces, the site is an aggregator of the works of others, but at least offers a spot for one-stop shopping. Adherence to the physics and science is not quite as strict as you maintain.

With regard to figure of merit, there is nothing wrong with looking hard at SWR. You will recall an article on searching too hard for the last bit of SWR could be harmful to one’s health! I post an insightful link to Owen Duffy regarding an obsession with chasing phase, but the phase of what? Impedance phase or of that presented by reliance on S11 phase, as the nifty RigExpert analyzers present. And as many amateurs seem to confuse.




Again, thanks for your continued contributions to the field!

Looking forward to a description of how much CMC choking you have in the baluns installed when you get a minute.

73
Ed McCann
AG6CX