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On Sat, Oct 5, 2019 at 06:39 PM, <bryburns@...> wrote:

I then used the T-Check equation found on page 12 of the file
"Reeve_S-ParamTestSet.pdf" found at



to compute the T-test result as a function of frequency which is plotted in
the attached ".jpg" file.

Hello Bryan,
I am trying to calculate the T-Check value from the NanoVNA-Saver .S2P file with LibreOffice Calc,
but I did not got the T-Check formular adopted.

I then copied S11 to S22 and S21 to S12

This is already done in the attached file T-CheckR31.S2P
I attached also a screen shot from NanoVNA-Saver T-Ceck measurement.
The 49.85 Ohm resistor was soldered in a SMA Female-Female Adapter,
see attached photo T-Check_SMA-F-F_49.85Ohm_DSC08169.jpg

Could you please explain in detail how you applied the formular?

73, Rudi DL5FA

Its in Octave (Matlab equivalent) for now till I know what algorithms to use
I have a S11 model for the cable (includes estimating the frequency dependent loss and the Complex static impedance (did not find any relevant frequency dependent higher order parameters)). Model parameter search using least squares based on the VNA measured data. It sounds so simple now I know what to do.......
--
Erik, PD0EK

Hi Erik -

I'm trying to create a VNA error model
to compensate for errors in the bridge and the Z0 reference

Do you plan a GitHub repository?

The model corrects for the long cable impedance mismatch for the 3GHz VNA

What approach for solving model parameters?

Hi Oristo
Here is the Screen control for the FA-VA5 I have received from AE5CZ Larry Goga and have permission to distribute as I like
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Oristo
Sendt: 5. november 2019 15:55
Til: [email protected]
Emne: Re: [nanovna-users] VNWA software #calibration

I still discover something new right click now and then ?

Sadly, I lack the playful approach.

it expanded gradually over the years to the fantastic complex level

Yes, I researched FA-VA5 before nanoVNA, but avoided the software until your prompting because of allergy to controls hidden in graphic user interfaces.
That is why "unhides" nanoVNA screen controls.

A new Wiki page may help others use VNWA software for nanoVNA calibrations:
/g/nanovna-users/wiki/VNWA-software-for-calibration

Hi Oristo
The Yahoo VNWA group is in the process to move to a io group which is a better platform for a Wiki which I am sure will come. I have large number of document I will "flood" the Wiki with in an orderly way
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Oristo
Sendt: 5. november 2019 15:55
Til: [email protected]
Emne: Re: [nanovna-users] VNWA software #calibration

I still discover something new right click now and then ?

Sadly, I lack the playful approach.

it expanded gradually over the years to the fantastic complex level

Yes, I researched FA-VA5 before nanoVNA, but avoided the software until your prompting because of allergy to controls hidden in graphic user interfaces.
That is why "unhides" nanoVNA screen controls.

A new Wiki page may help others use VNWA software for nanoVNA calibrations:
/g/nanovna-users/wiki/VNWA-software-for-calibration

And here is the nanoVNA data with the impedance correction for the long cable ( -0.075 -0.56i ohm)
Substantial oscillations are still there and these do NOT come from the calibration kit or the cable so must come from the bridge or an interaction between the bridge and the cable.
Next step in modelling to be taken
--
Erik, PD0EK

I still discover something new right click now and then ?

Sadly, I lack the playful approach.

it expanded gradually over the years to the fantastic complex level

Yes, I researched FA-VA5 before nanoVNA,
but avoided the software until your prompting
because of allergy to controls hidden in graphic user interfaces.
That is why "unhides" nanoVNA screen controls.

A new Wiki page may help others use VNWA software for nanoVNA calibrations:
/g/nanovna-users/wiki/VNWA-software-for-calibration

On Tue, Nov 5, 2019 at 05:48 AM, gin&pez@arg wrote:
Dear gin&pez@arg
How are you sure the errors to be corrected are larger than the uncertainty in your measurement. e.g. you are not trying to correct an already (almost) perfect VNA?

--
Erik, PD0EK

And here is a hint a first order cable correction (assuming the cable impedance is not exactly Z0) can improve the results
The model corrects for the long cable impedance mismatch for the 3GHz VNA
Mismatch is identified to be frequency independent and around -0.015-0.769i ohm, impact is visible in the upper left chart yellow/orange logmag S11 of the long cable which becomes more of a straight line. Now I can use this approach to reduce the cable impact on the other VNA's and see what is left to correct in the bridge.

--
Erik, PD0EK

#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#

Hi Oristo

Good to hear about success.
It may be a crazy user interface for you being a custom to something else, but not really for me as been the only VNA for me since it's birth. It is for more than 10 years and I still discover something new right click now and then ?
It started as a DG8SAQ Tom Baier "birdnest" ham project, and concept verified by student project at ULM University, where Tom is a teacher and then it expanded gradually over the years to the fantastic complex level it has to day.

Kind regards

Kurt



-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Oristo
Sendt: 5. november 2019 12:29
Til: [email protected]
Emne: Re: [nanovna-users] VNWA software #calibration



Hi Kurt -



Thanks for the additional hints, so essential success!

double click on any trace type name on the lower line

... which for the attached VNWA main window are 'Log Mag' or 'Smith'

the page come up with all the trace settings

.. which is titled 'Display Settings', also attached

another long drop down list S21, S11, S12, S22 and so on, and here you

find the 6 custom traces.

... shown below with Custom1/Custom2/Custom3 selected for 'Smith' and 'log magnitude'

the top Expression line are fully individual...

Each custom trace can be given a Caption name

.. shown below with Expression 's_open' and Caption: 'open'



Then, by clicking any of 'short', 'open' or 'Load' words next to check boxes below plots, not the plot lines, then a dialog box appears with an option for 'Export Trace to s1p'

There are many other feature by right clicking around.

It is IMO a crazy user interface, perhaps if all were by right click instead of some by left double-click..

Anyway, s1p files exported, then can plot in gnuplot, revealing differences between open and short logmag

Hi Rune,

The new TDR impedance measurement is good too.

However it really could use the ability to manually scale the impedance in addition to the length, as the low impedance end of the scale is too compressed to read when used with typical coax in auto-scaling mode.

Regards,

Martin - G8JNJ

Hi Martin,
thanks for the bug report. I'll have a look at it (and probably a fix!) for
the next version :-)

--
Rune / 5Q5R

On Tue, 5 Nov 2019 at 12:56, Martin via Groups.Io <martin_ehrenfried=
[email protected]> wrote:

Hi Rune,

Thanks for the latest update, especially the ability to change the marker
size and the relabeling of the Series L & C values

One small bug I've noticed is that the Marker number on the S11 R+Jx graph
is incorrect, as it always shows as zero.

Regards,

Martin - G8JNJ

From: Rune Broberg

I just released NanoVNA-Saver 0.1.5:


[]
As ever, dear mailing list users, I very much look forward to your comments, feedback, suggestion and bug reports. I already have a number of things I want to try to get done for next week - so it shouldn't be a 2-week gap this time around! :-)

Thank you to all the testers who helped me fix the bugs in the first two alpha releases of this!
[]
==================================

Thanks Rune, working with the nanoVNA-F - current firmware. I particularly appreciate the TDR impedance plot addition.

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

Hi Rune,

Thanks for the latest update, especially the ability to change the marker size and the relabeling of the Series L & C values

One small bug I've noticed is that the Marker number on the S11 R+Jx graph is incorrect, as it always shows as zero.

Regards,

Martin - G8JNJ

Hi Kurt -

Thanks for the additional hints, so essential success!

double click on any trace type name on the lower line

... which for the attached VNWA main window are 'Log Mag' or 'Smith'

the page come up with all the trace settings

.. which is titled 'Display Settings', also attached

another long drop down list S21, S11, S12, S22 and so on,
and here you find the 6 custom traces.

... shown below with Custom1/Custom2/Custom3 selected for 'Smith' and 'log magnitude'

the top Expression line are fully individual...
Each custom trace can be given a Caption name

.. shown below with Expression 's_open' and Caption: 'open'

Then, by clicking any of 'short', 'open' or 'Load' words next to check boxes below plots,
not the plot lines, then a dialog box appears with an option for 'Export Trace to s1p'

There are many other feature by right clicking around.

It is IMO a crazy user interface, perhaps if all were by right click instead of some by left double-click..
Anyway, s1p files exported, then can plot in gnuplot, revealing differences between open and short logmag

And here are the plots for the 3GHz VNA with the bridge rotated 180 degrees. Still without HW correction model.
All differences are coming from a change in bridge HW.

--
Erik, PD0EK

Free (in the USA) diodes available for battery indicator

I have 99 "extra" 1N4148WS diodes available.

If you want any, FOR FREE IN THE USA, send me a self-addressed stamped envelope and how many diodes you need. Email me for my address.
Roy K2RMA@...

Attached the plots you requested
All data from 3 VNA's calibrated with the same calibration kit measuring the same two cables

1: nanoVNA
2: ownVNA
3: 3GHzVNA

No VNA specific corrections applied

Top right is the smith chart plot of the calibration kit to prove the calibration was done correctly. I use "+" to plot the data otherwise it would be impossible to see the dot's as they are exactly on the same location and too small to see

The smith charts of the cables (bottom two) include the plot where the reference plane is set to the end of the cable (all VNA's with exactly the same shift per cable, labeled with "rotated") so you can easily see the remaining errors
And yes, some cables move outside the smith chart at higher frequencies and that is indeed the problem I try to solve with a VNA specific error correction approach


--
Erik, PD0EK

I just released NanoVNA-Saver 0.1.5:



Release notes:
This release, after a short break in the release schedule, offers a few new
features and improvements:

Configurable Markers
There are a number of new configuration options for markers:

The size of the markers can be changed under Display Setup,
Marker numbers can be displayed in the charts,
Marker data box headings can be coloured or not, depending on user
preference,
The data displayed for markers is now configurable
Impedance Analysis
The Time Domain Reflectometry window now has a display of an impedance
transform, showing the calculated impedance of the transmission line the
NanoVNA is looking at from the calibration plane onwards.

New analyses - and automatic running
The Analysis window has two new analysis options, peak search and VSWR
analysis. It also adds the option to run the analysis automatically
whenever new data is acquired, for example for adjusting filters.

Frequency display changed
DG5DBH kindly sent me updated functions to display frequencies on GitHub.
You can still enter frequencies in the manner you are used to, as Hz, kHz
or MHz, but now calculated or read frequencies should more consistently be
displayed in a nicely formatted way.


As ever, dear mailing list users, I very much look forward to your
comments, feedback, suggestion and bug reports. I already have a number of
things I want to try to get done for next week - so it shouldn't be a
2-week gap this time around! :-)

Thank you to all the testers who helped me fix the bugs in the first two
alpha releases of this!

--
Rune / 5Q5R