开云体育

#66: Public Invitation : #66

Hello,

Allow us, please, to generally express our clear point of view
on these extraordinary stupid demands expressed by impotent
members of this group, by addressing in particular our valuable
collaborator in this very topic, Gary O'Neil, as follows:

Dear Gary,

We gradually read your huge valuable work and we think
that it certainly will be an honer for us if you will accept
this public invitation to participate with us, as the first
co-author of course, in a Series of Papers to be published
in our small-but-honest research journal FTP#J, with subjects
beginning with those research results that you and we
produced here - after a so hard work as productive doers
of course [*].

Therefore, if you -as well as any other Fellow in Knowledge,
of course- are interested enough in the open and free publication
on these matters, then do not hesitate to contact us, please,
at this email address :

yzavna@...

anytime you will feel that you are ready for such an attempt.

Meanwhile, as we already predicted with our very early
messages:

#8 - 21 September 2019 :
/g/nanovna-users/message/3004

#9 - 25 September 2019 :
/g/nanovna-users/message/3040

we are going to save our contributions in this group,
without any of these interfering nuisances of course,
which obscure and defame our research work, at:



Farewell !

[*] and not just as impotent totalitarian lazy talkers, whose their
main job in this particular case is dual :

- on the one hand, to hide from the innocent Common User the
fact that the least operation of any VNA is just as simply as our
two step process based totally on its measurements and nothing
else, as well as

- on the other hand, to mute the fact that there are errors in any
VNA results, which under more than less circumstances may
become so extremely large that its computed measurements
become totally unreliable.

That's all.

Sincerely,

gin&pez@arg

66#

#67 : On [TheLeastVNA] : 18 Questions and 15 Answers

@Gary O'Neil - 17 October 2019 :
/g/nanovna-users/message/5081

Dear Gary,

It is our pleasant duty to reply your specific Questions regarding our work !

However, allow us, please, to not make any comment or to comment any
of your conclusions, regarding the comparison of the Qualities of our
instruments, simply because we do not consider appropriate to do so.

Well, after all that said, let's proceed as follows:


Q1 : "What were the Putty commands you used to extract data from the NanoVNA?"
-
A1 : The commands to [NanoVNA] through PuTTy are [info], [frequencies] and [data],
as these are shown as "headers" inside the following data files:

[info]

[frequencies]:


[data]:





but take into account, please, that you have to edit all data files in order
to remove any such "headers" and leave just 101 lines of data, if you
intend to use them with the current version of [TheLeastVNA]:



=

Q2 : "Can you confirm the data as raw (uncorrected) or post calibration
corrected measurements?"
-
A2 : Yes. Right after you finish with each measurement s, l, o, g of S, L, O, G
you command with the PuTTy : [data], so the measurements are shown in
PuTTy's console window and then you have to select, copy, and paste them
to the corresponding file.

=

Q3 : "Your VNA data (blue) appears to have been taken at a significant offset
from the reference plane. If this is uncorrected raw data it makes sense in an
automated VNA environment."
-
A3 : Not at all - Our VNA data were taken exactly on the same reference plane.
Otherwise a comparison would not be possible at all - Please, be careful at this
very point - You have been warned

=

Q4-7 : "I am interpreting your full final report 1 as follows:" "1. ..." "2. ..." "3. ..." "4. ..."
-
A4-7 : Yes - Yes -Yes - Yes

=

Q8 : "The variables used in the gamma equation shown are assumed to be the
complex values..."
-
A8 : Yes

=

Q9 : "There are no numerical values or constants in the equation..."
-
A9 : Yes

=

Q10 : "There are no calibration correction coefficients used in producing
any of this data, nor in any of the computed results plotted in this report."
-
A10 : No - The so called "calibration" procedure is hidden in our compact
computation of Reflection Coefficient of the Unknown load.

Q11 : "To that point, the calibration standards used are considered ideal and
perfect."
-
A11 : Not at all - The manufacturers of these 'standards' declare their NOMINAL
VALUES and thus we are obliged to take these NOMINAL VALUES exactly
- Please, be careful at this very point - You have been warned

=

Q12 : "The upper case gamma is the computed complex result of this equation
representing the corrected measured value of the DUT, and is interpreted as
the reflection coefficient of the DUT at the measurement frequency."
-
A12 : Yes

=

Q13: "This then enables one to graphically visualize the nominal result differences
between..."
-
A13 : Yes

=

Q14 : "The inference that one can observe..."
Q15 : "The NanoVNA is clearly shown, not surprisingly, to be inferior in performance..."
Q16 : "As to whether or not the..."
-
A14-16 : We don't want to comment to the slightest on these - These are exclusively
your conclusions

=

Q17 : "Part 3 of 3 (III / III) is simply the computed complex impedance..."
-
A17 : Yes

=

Q18 : "This is all quite encouraging. I believe that I am now following your process up
to this point. If any of my interpretation to this point is in error, I trust you will correct
me where needed."
-
A18 : Thank you very much, indeed - The trustfulness is always mutual.

Best regards,

gin&pez@arg

67#

#68 : On The Most Reliable Comparison of [NanoVNA] with
any laboratory [VNA]

Hello,

Allow us, please, to inform you that we just revised the first
part of our previous answers [*] to our Fellow in Knowledge
Gary O' Neil, N3GO, in a way more general than that
personal one, as follows:


Q 00 GON : "I wish to have some clarification that I am
interpreting the test configuration correctly."

A 00 GZA : It is our pleasant duty to reply your specific
Questions regarding our work !

-

Q 01 GON : "What were the Putty commands you used to extract data
from the NanoVNA?"

A 01 GZA : The commands to [NanoVNA] using PuTTy are: [info],
[frequencies] and [data], as these are shown as headers inside
our data files, in order to make perfectly clear what we are
talking about, that is:

[info] to get the specific firmware information of [NanoVNA]

[frequencies] to get the 101 frequencies at which our [NanoVNA]
makes its measurements f by default, into a file with a name
clearly showing the letter f

[data] to get the 101 measurements at these 101 frequencies,
right after the connection and measurement of each of the four
4 needed loads, as follows:

SHORT, into a file with a name clearly showing the letter s,

LOAD, into a file with a name clearly showing the letter l,

OPEN, into a file with a name clearly showing the letter o, and

GAMMA, into a file with a name clearly showing the letter g

(see reference [1], please, just after the end of this text),
but take into account, please, that you have to edit all these
files in order to remove any headers and leave just 101 lines of
data, that is the number of frequencies of our [NanoVNA], if you
intend to use them with the current version of our [TheLeastVNA]
code (see [2]).

-

Q 02 GON : "Can you confirm the data as raw (uncorrected) or post
calibration corrected measurements?"

A 02 GZA : Sure. These data were directly obtained right after
each of the four needed measurements [A 01] shown in PuTTy's
console window and then selected, copied, and pasted to the
corresponding file [A 01]

-

Q 03 GON : "Your VNA data (blue) appears to have been taken at a
significant offset from the reference plane."

A 03 GZA : Not at all. Our [VNA] data were taken exactly on the
same reference plane as that of our [NanoVNA]. Otherwise a
comparison between the results in our Full Final Report 1
(see [3]) would not be possible at all, as it would not make any
sense at all. Please, be careful at this very point - you have
been warned.

-

Q 04 GON : "If this is uncorrected raw data it makes sense in an
automated VNA environment."

A 04 GZA : Yes, but not only.

Since, as you can see, this also can make sense in our [NanoVNA]
environment too, because it was by this most appropriate use of
it that we were finally been in the place to compare it in our
way with our [VNA], in the most reliable way.

In fact:

* W e * c o u l d * n o t * c u r r e n t l y * s e e * a n y *
* o t h e r * w a y * t o * d o * a * r e l i a b l e *
* c o m p a r i s o n * o f * a n y * [NanoVNA] * w i t h *
* e x i s t i n g * l a b o r a t o r y * e q u i p m e n t *
* a r o u n d * o f * [AnyVNA], * o t h e r * t h a n
* t h i s * v e r y * w a y * w e * f o l l o w e d * i t *.

But, if you can - or any other Fellow in Knowledge member of
this Group can - suggest another one, more reliable way than of
ours, please let us know accordingly.

Sincerely,

gin&pez@arg

References

[*]
#67 : On [TheLeastVNA] : 18 Questions and 15 Answers
/g/nanovna-users/message/5428
21 October 2019

-

[1] The needed data files

[info]: header in all of the following files

[frequencies]: sub-header in:


[data]: sub=header in:





-

[2] The Code

The core statements
#54 : [TheLeastVNA] Code with an Application to [NanoVNA]
/g/nanovna-users/message/5137
18 October 2019

The Instructions to use [TheLeastVNA]
#59 : UPDATE : [LeastVNA] : version 20191020
/g/nanovna-users/message/5269
20 October 2019

The current version
#65 : [TheLeastVNA] Code - Update 20191020
/g/nanovna-users/message/5356
20 October 2019

Direct Download:


-

[3] The Full Final Report 1:
#51: the full final report 1 with contiguous full online images is
here :

17 October 2019
/g/nanovna-users/message/5063

68#

gin&pez@arg

Greetings, and thank you for the kind words and your clear and thorough response to my long list of 18 questions. Please accept my apologies for the very long deferral in my response, but be assured that I have not been idle on this topic.

I replicated your BBC BASIC program in a spreadsheet and confirmed that my results are very close but not identical. I have not yet concluded the difference to be one of math precision, but this does appear to be the case. Beyond that; I have been using the spreadsheet as a study aid as I become more familiar with your work. This has been both fruitful and enlightening, but I am ignorant of much of the mathematical details. It has been a long journey of discovery for me, and I am grateful for your patience.

There are more than 100 posts in this thread. I return to review those that are focused and relevant; only to discover what you previously informed us about. My growth in understanding eases the task of interpreting your work that was not clear or sufficiently detailed to understand until now. Perhaps my ignorance may be serving as a benefit to you by sharing our communications with the English speaking world.

I am flattered by your offer to participate as a supporting contributor to your work, but I hardly have the credentials for doing so. If I had an advanced degree, it would be a PhD in tenacity and persistence from Hard Knocks University. :-) I don't quite know how that remark might translate; so I will explain that it is intended as a metaphorical way of saying that I work hard and overcome obstacles. I got paid but not graded for my efforts. Now that I'm retired; I do this for fun. You are certainly welcome to publish freely anything I have written here, and anything in the way of test results or data that you might ask me to contribute.

Now back on topic...

On your answer A3:

"A3 : Not at all - Our VNA data were taken exactly on the same reference plane.
Otherwise a comparison would not be possible at all - Please, be careful at this
very point - You have been warned "

I understand, and I concur. My question was imprecise, but is now answered,

Your answer A10:

A10 : No - The so called "calibration" procedure is hidden in our compact
computation of Reflection Coefficient of the Unknown load.

Perfect... This validates my observations precisely, and is what I have been reluctant to confess. I have not attempted to study the mathematics of how calibration is performed traditionally, but your algorithm is simple, concise, and clearly results in a calibrated reflection coefficient that overlays the corrected results of the NanoVNA almost exactly.

Your approach is both elegant and provocative. I most recently observed that the measurements (all reflection coefficients) are piecewise linear across significantly large spans of frequency. I am planning a simulation and experiment to validate the utility of this, and I will post any results that appear useful. I have also been looking at using your algorithm to compare my NanoVNA with a simulated "perfect" VNA as a candidate reference standard for comparing hardware much like an isotropic antenna serves as a reference to which all antennas are compared. The early results of this look exciting, and suggests that it may be possible to characterize and calibrate the response of the overall VNA test station itself. For now however; much of this remains observational speculation.

I respect and concur with your response (A14-16:)

A14-16 : We don't want to comment to the slightest on these - These are exclusively
your conclusions.

I agree... the evidence in the data is circumstantial and inconclusive.

Thank you again for sharing this openly in the amateur radio community. VNA's are new to many hams; but as they become common, your work will gain the recognition it deserves.

--
73

Gary, N3GO

#69 : combined fortran, maxima and gnuplot code for [errors in "error" models]
-
references:
Jose Luu - 3 October 2019 : /g/nanovna-users/message/3812
Gary O'Neil - 17 October 2019 : /g/nanovna-users/message/5075
#60 - 20 October 2019 : /g/nanovna-users/message/5312

Hello,

Allow us, please, to inform you that we are in the process of revising and updating
our combined code for [errors in "error" models], so we are still staying far behind
of the replies we owe regarding the specific questions about our work
-
please accept our apologies.

Also, allow us, please, to inform you that during this process we need to tediously
look in various volumes of those nineteen 19 consisting the huge accompanying
documentation of [open watcom 2.0] (2017), so we thought to concentrate them,
by using the current version 9.5 of the free [pdfShaper]:



in just one very "handy" PDF volume of 6,136 pages, definitely responding to the
[Find] and [Search] capabilities of the free [PDFXchange] viewer:



which we just uploaded to [archive.org] at:



Sincerely,

gin&pez@arg

: 69#

gin&pez@arg

1) The pdf document you have provided and archived for us is written for a C++ complier. This document plus the subtitle of this post "combined fortran, maxima and gnuplot code for [errors in "error" models]", implies to me your intention to port your Fortran code into the C++ environment, and provide the C++ version here for the convenience of this group. Is my interpretation of your intent correct on this?

2) Please confirm that the G-mini equation you have derived and posted here:



is a "minimal" one port subset of the full set of two port equations posted here:



3) The Nominal values for the SOL standards in the G-mini equation assumptions in #17 at:

/g/nanovna-users/message/4747

are (numerically) defined as perfect. Neither of the above equations provide for standards characterization influences. Are the standards inaccuracies defined and embedded in the uncertainty boundary definitions?

4) The equations defined at



a) The set of Equations (0) through (8) are void of calibration/characterization data, and only require reflection SOL calibration measurements of a single port (S11?). Please confirm that both one and two port calibration is embedded in these calculations, and also confirm that SOL measurements are required on only one port, with the through reference plane defined by the SOL standards used to perform the calibration.
b) Equation (0 ) and its inverse Equation (8) are unclear. I assume the upper case Gamma is the computed reflection coefficient, and the lower case gamma is the measured (DUT) reflection coefficient. Please confirm.
c) In Equation (0), please confirm that S12S21 is an intermediate variable defined in equation (6), and does not imply S12 * S21.
d) In Equation (0), S11 is summed with the computed result of all remaining calculations defined as Equation (0). In other words S11 + (S12S21 * G) not (S11 + S12S21) * G
d) Equations (1) through (4) define the common intermediate denominator D, and intermediate numerators N11, N21N21, and N22 used in Equations (5), (6), and (7) respectively.
e) Equations (5) and(7) are the final calculated reflection coefficient results.
f) Equation (6) is a calculated transmission coefficient. Please explain how to differentiate between forward and reverse transmission results.
g) Uncertainties due to errors in accuracy, and those accounted for through characterization of the calibration standards used (by their absence here) are removed to the DERDEI contour calculations by the relevance of their contributions to the overall uncertainty in the accuracy of the measurements.
h) These equations alone will yield measurement results no better, and no less accurate than existing calibration processes, but are computationally much more efficient.

5) If my interpretation in 5 a) is correct, and only one port is required to be SOL calibrated; have you validated and compared these equations independently for each port in a full two-port system, calibrated with one set of SOL measurements performed at both ports uniquely and independently? This "validation" task cannot be completed on the NanoVNA which has only one reflection port.

6) The forthcoming C++ software (ported Fortran code) will produce the DERDEI (uncertainty) contour calculations given reflection and/or transmission coefficient measurement results and a file of uncertainty boundary estimates as inputs. It is anticipated that the DERDEI uncertainty contour tool will be independent of the calibration algorithm outlined in 4 above, and thus serve the VNA community overall, without compromise, using reflection/transmission coefficient results provided from any source. To that end; I continue to recommend the use of the Touchstone format as the data format of choice for data entry into the DERDEI tool.


73

Gary, N3GO

#70: facupov : a 64-bit working maxima under windows in 2 cases

Hello,

Allow us, please, to inform you that after hard days-and-nights
of many-many trials-and-errors, including tedious searching for
the lemmas below (e.g. in [1]-[3]), we just succeeded to install
in two 64-bit Windows systems in our PC of an AMD CPU, a Working
64-bit Maxima, but with the cost of disabling the whole DEP
(Data Execution Prevention) Protection in these Windows systems
-
* That * Is * You * Have * Been * Warned *
-
as follows:

- - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - -

I/II : w7p64

(1) Run as Administrator:

| wmic OS Get DataExecutionPrevention_Available

the right reply is:

| DataExecutionPrevention_Available
| TRUE

if not, then STOP trying - FAILURE.

(2) Run as Administrator:

| BCDEDIT /SET {CURRENT} NX ALWAYSOFF

(3) Restart

(4) Run as Administrator:

| wmic OS Get DataExecutionPrevention_SupportPolicy

the Right Reply is:

| DataExecutionPrevention_SupportPolicy
| 0

if not, then STOP trying - FAILURE.

(5) Run:

| E:\maxima-5.43.0\bin\lispselector.bat

Select : CLISP

(6) Run Xmaxima

the Right Response is:

| Lisp CLISP 2.49 (2010-07-07)

if it is, then : SUCCESS

if not, then:

(7) Run:

E:\maxima-5.43.0\bin\lispselector.bat

Select : SBCL

(8) Run Xmaxima

the Right Response is:

| Lisp SBCL 1.4.14

if not, then stop trying : FAILURE

if it is, then : SUCCESS.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

II/II : wxpp64&sp2

(1) Create a desktop shortcut icon for cmd.exe
Mouse Right Click on cmd.exe icon
Select: Run as...
(o) Current user (...)
[v] Run this program with restricted access

and uncheck it to:

[ ] Run this program with restricted access

(2) In this Command Window run:

| wmic OS Get DataExecutionPrevention_Available

the Right Reply is:

| DataExecutionPrevention_Available
| TRUE

if not, then stop trying - FAILURE

(3) Select:

|Start|Settings|Control Panel|System|Advanced|
|Startup and Recovery|Settings|Edit|

go to the line of this wxpp64&sp2 system in boot.ini
and add the switch:

| /NOEXECUTE=ALWAYSOFF

(4) Restart

(5) Mouse Right Click on cmd.exe icon
Select: Run as...
(o) Current user (...)
[v] Run this program with restricted access
uncheck it to:
[ ] Run this program with restricted access

(6) In this Command Window run:

| wmic OS Get DataExecutionPrevention_SupportPolicy

the Right Reply is:

| DataExecutionPrevention_SupportPolicy
| 0

if not, then stop trying - FAILURE

(7) Download and install gnuplot 5.0.7 64-bit [1]
on your system disk "X" at:

| X:\Program Files\gnuplot

(8) Download and install 64-bit maxima-5.43.0 [2]
on your system disk "X" at:

| X:\maxima-5.43.0

but take into account, please, that * t h i s * Maxima also
installs the 64-bit gnuplot 5.2.7 at your system disk "X" at:

| X:\maxima-5.43.0\bin\gnuplot

(9) Copy the whole:

| X:\Program Files\gnuplot

over:

| X:\maxima-5.43.0\bin\gnuplot

(10) Run:

| E:\maxima-5.43.0\bin\lispselector.bat

Select : SBCL

(11) Run Xmaxima

the Right Response is:

| Lisp SBCL 1.4.14

if it is, then: SUCCESS

if not then:

(12) Run:

| E:\maxima-5.43.0\bin\lispselector.bat

Select : CLISP

(13) Run Xmaxima:

the Right Response is:

| Lisp CLISP 2.49 (2010-07-07)

if not, then stop trying - FAILURE

if it is, then : SUCCESS.

- - - end : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - -

References:

[1] -, "Installation of Maxima in Windows":


[2] MS Support, "How to determine that hardware DEP is available
and configured on your computer":

Last Updated: Apr 17, 2018

[3] Rajesh Babu Ramachandran, "How To Enable or Disable DEP In
Windows XP, Vista or windows 7?":


[4] maxima-clisp-sbcl-5.43.0-win64.exe:


[5] gp507-win64-mingw.exe:


Sincerely,

gin&pez@arg

:70#

Sounds painful...

The Maxima install was uneventful here under Windows 10 on my desktop. It looks like learning how to use it is going to be my next hurdle. :-) I have verified that all three user interfaces appear to be working properly.

--
73

Gary, N3GO

HI Gary -

The Maxima install was uneventful here under Windows 10 on my desktop.

Did you only follow these instructions:


.. without any DataExecutionPrevention steps?

Hello Oristo;

Yes... Those were the instructions that I followed. It's a bit of an odd tool to use though. I suppose if mathematics is your first language it makes sense; and you will be comfortable with it. It looks like it's going to be a very steep learning curve for me.

I was able to copy and paste the "DERDEI-unpacked_20191001-600-1000.MC" source into the wxMaxima GUI and get it to run following the guidance provided for doing it this way in the Oct 2 post # 3770. That might suggest forward progress, but I still have a lot of ground to cover before I'm going to be able to achieve this task on my own. The output is the 6 gnu plots that are described, and are what I believe to be the end goal of this project.

I managed to get the OpenWatcom Fortran compiler installed and responding, but I remain clueless on what and how to link the source files, the 4, reflection coefficient files, the uncertainty limits file, and how to compile them into an executable file that generates the files used for the plots. I've done limited assembly level programming Altair's and PICs, and even less C (Arduino) programming, so I know enough to recognize the environment is different than a Spice simulator, and that's pretty much how far up the learning curve I am with Fortran.

It is comforting to know that there are others that are taking note of the work being done here.


73

Gary, N3GO

gin & pez;

It has been a productive day for me today. I just completed getting "open-watcom-f77-win32-1.9" installed and running, and I was able to successfully compile the files from DERDEI20191001, run the executable, and produced the PDEIS and RDEIS uncertainty output files, several 3D object files, and multiple others. I now have only to bridge the interface from the Fortran output into wxMaxima to enable GNU plotting, and I soon will be able to replicate your work from start to finish.

--
73

Gary, N3GO

#71: Good News : (1) DEP was Restored and Maxima is still Working in these 2 cases :
[WXP64P&SP2] and [W7P64], (2) Maxima Worked Immediately in [W8.1P64]

@Oristo - 2 November 2019 : /g/nanovna-users/message/6348
@Gary O'Neil - 2 November 2019 : /g/nanovna-users/message/6338
@Gary O'Neil - 3 November 2019 : /g/nanovna-users/message/6360

Hello,

We thank you very much both of you for your valuable comments !

Because, it was only after your remarks on the installation and run on your [W10]
without DEP problems of:

maxima-clisp-sbcl-5.43.0-win64.exe

that we motivated to return on this subject and thus to check and confirm -with much
pleasure, indeed- the following:

(1) Yes, indeed, Maxima was also installed and ran immediately, without any further
problems, under [W8.1P64] at our multi-boot PC with AMD CPU.

(2) The DEP Protection was restored in both cases:

I/II [W7P64] :

=> wmic OS Get DataExecutionPrevention_SupportPolicy
<= DataExecutionPrevention_SupportPolicy
<= 0

=> BCDEDIT /SET {CURRENT} NX OPTIN

=> Restart

=> wmic OS Get DataExecutionPrevention_SupportPolicy
<= DataExecutionPrevention_SupportPolicy
<= 2

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

II/II [WXP64P&SP2] :

=> wmic OS Get DataExecutionPrevention_SupportPolicy
<= DataExecutionPrevention_SupportPolicy
<= 0

Remove the switch:

/NOEXECUTE=ALWAYSOFF

Restart

=> wmic OS Get DataExecutionPrevention_SupportPolicy
<= DataExecutionPrevention_SupportPolicy
<= 2

(3) Maxima works with either Lisp CLISP 2.49 (2010-07-07) or Lisp SBCL 1.4.14,
as follows:

CLISP:
OK : WXP64P&SP2
OK : W7P64
OK : W8.1P64

SBCL:
OK : WXP64P&SP2
NO : W7P64
OK : W8.1P64

(4) In all 3 cases, we allow in our Firewall the incoming network connections for the
[Wish] Application:

X:\maxima-5.43.0\bin\wish86.exe

(5) More on all that you can find at the very same named thread at Maxima-Discuss:



Sincerely,

gin&pez@arg

:71#

GIN & PEZ@arg;

Excellent news to hear.

Have you done any recent IEEE publication or presentations of the work you are presenting here, or have plans for presenting at any Conferences?

--
73

Gary, N3GO

GIN & PEZ@arg;

New results to please you all the more. I just replaced your mini equation:



with your even smaller equation as presented in Part 3 of your 5 part series as equation (6):

Measurement Uncertainty in Network Analyzers: Differential Error
Analysis of Error Models Part 3: Short One-Port Calibration - Comparison:


Which reduces the equation to a single calibration measurement (Short) only, and reduces the computation to simply:

G=m/s

The results of this exercise appear to confirm your conclusion in that paper. I am amazed by how close they agree with those of the full one-port cal and that of your mini-equation.

I will gather and post more detail on my observations tomorrow.

--
73

Gary, N3GO

The very "short" one port equation does get meaningfully close, but diverges with frequency. I haven't computed the impedance deviation yet, so it's too soon to pass judgement. My spreadsheet is getting uncomfortably out of control; and as I am understanding more, it expanded and has become difficult to manage. Before I continue from here, I need to do a refresh/rewrite to get it better organized and to keep it from becoming corrupted. This may take a few days.

--
73

Gary, N3GO

G=m/s

The results of this exercise appear to confirm your conclusion in that paper.
I am amazed by how close they agree with those of the full one-port cal and
that of your mini-equation.

That works when short and open results are similar and load signal is small.
Small load signal is generally easy for resistance bridge at low frequencies,
not so much for reflection bridge and higher frequencies.

Open = short works better for nearly no distance from bridge to DUT,
not so well for real cables of some length.

Sorry for question, but what means word "facupov"?
It is often mentioned here, but I cannot understand what you're talking about...

Just tried to google it, but unfortunately with no success

From A Common User's Point of View

apparently "facupov" is pseudo for "from a common user's point of view",

#72 : facupov : confirmation and suggestion

@QRP RX - 5 November 2019 : /g/nanovna-users/message/6471
@Bob Albert - 5 November 2019 : /g/nanovna-users/message/6472
@ johnshouse100@... - 5 November 2019 : /g/nanovna-users/message/6473

Hello,

Thank you very much for your interest on this central point of our work and thus
allow us, please, not only to confirm your guessing but also to suggest you the
reading of the following message:

#62 : On the Most Reasonable Questions with the Most Clear Answers
20 October 2019 : /g/nanovna-users/message/5334

Sincerely,

gin&pez@arg

: 72#