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Date
Re: Anmeldung

 

On Sun, Jun 12, 2022 at 07:20 AM, @Alex1961 wrote:


Sorry, my english is not good. I need software to cinfig the nano vna.
Thank you.
Try NanoVNA Saver >>

Roger
Anmeldung

 

Sorry, my english is not good. I need software to cinfig the nano vna.
Thank you.
Re: 2port measurement determining Zdut with S11 and S21

 

Thanks Stan for this feedback. Anyfeedback is very welcome.
I put click-on ferrites (25mm long) on port1, port2 and USB cables, they
have (in my setup) no significant effect on the measured S21 (or S11)
2port series through measurements.

Anyway, all feedback is very welcome. Every question/query/remark can help
to pinpoint things more precisely. Thanks.

All the best,

Victor

Op zo 12 jun. 2022 om 05:31 schreef Stan Dye <standye@...>:

Victor, I notice that in these examples you are using the nanoVNA with the
saver software, connected to a computer via USB cable.

When I do a similar setup, I note that the USB cable to the computer can
significantly affect the measurement at HF frequencies. I found that I
had to use a high quality cable and put ferrite beads on it to decouple
that RF path. You may wish to experiment with that to see if it gives you
better stability in your results.

On Sat, Jun 11, 2022, 4:22 PM Victor Reijs <pe1atn.victor.reijs@...>
wrote:

I forgot to add that the NanoVNA measured Impedance (based on the S21 (or
S11) 2port series through):
[image: afbeelding.png]
matches quite nicely the theoretical simulation of a choke:

[image: afbeelding.png]

<the theoretical simulation got one parameter (stray capacitance of the
choke, not of the testing gear!) which was derived by matching the peak
in
the simulation with the peak in the measured S21 curve>

I think I am more or less understanding what/how is measured with the
NanoVNA. Will try to make a web page out of that.

All the best,

Victor



Op za 11 jun. 2022 om 08:32 schreef Victor Reijs via groups.io
<pe1atn.victor.reijs@...>:

Hello Roger,

Using Series though, the NanoVNA measures both a S11 and S21 (for that
configuration, which I [of course] calibrated). The link I gave (
), calculates the Zdut
using
these Sx1 from the 2port series through measurement. In the case of the
resistive DUTs the S11 measured with 2 port (red blue dotted) is almost
identical with the S11 measured with 1 port (orange dotted). The same I
see
with the toroid DUT.
But I am not able to map the Zdut calculated with the S21 (green
dashed;
measured in the series through 2 port).

So the Zdut (Zx) using with 2port series through and S11 based is
different
from Zdut (Zx) using (the same) 2 port series through and S21 based. So
all
stray capacitances, etc are the same (which I see part of the DUT).

All the best,

Victor

Op za 11 jun. 2022 om 07:26 schreef Roger Need via groups.io
<sailtamarack=
[email protected]>:

Victor,

I am not sure how you are measuring the DUT using S11 reflection and
S21
series methods.

You have to measure them with the correct reference plane calibration
and
this usually requires two different test jigs. What are you using
for
S11
and S21 test jigs? Attached is one I use for S11 up to 30 MHz. I
tack
solder the DUT as shown. My example uses an inductor but you can
solder
the leads to your choke. The second one I built into a box and it
works
well too. I posted my S21 series jig in the last topic

Roger
Re: 2port measurement determining Zdut with S11 and S21

 

Victor, I notice that in these examples you are using the nanoVNA with the
saver software, connected to a computer via USB cable.

When I do a similar setup, I note that the USB cable to the computer can
significantly affect the measurement at HF frequencies. I found that I
had to use a high quality cable and put ferrite beads on it to decouple
that RF path. You may wish to experiment with that to see if it gives you
better stability in your results.

On Sat, Jun 11, 2022, 4:22 PM Victor Reijs <pe1atn.victor.reijs@...>
wrote:

I forgot to add that the NanoVNA measured Impedance (based on the S21 (or
S11) 2port series through):
[image: afbeelding.png]
matches quite nicely the theoretical simulation of a choke:

[image: afbeelding.png]

<the theoretical simulation got one parameter (stray capacitance of the
choke, not of the testing gear!) which was derived by matching the peak in
the simulation with the peak in the measured S21 curve>

I think I am more or less understanding what/how is measured with the
NanoVNA. Will try to make a web page out of that.

All the best,

Victor



Op za 11 jun. 2022 om 08:32 schreef Victor Reijs via groups.io
<pe1atn.victor.reijs@...>:

Hello Roger,

Using Series though, the NanoVNA measures both a S11 and S21 (for that
configuration, which I [of course] calibrated). The link I gave (
), calculates the Zdut
using
these Sx1 from the 2port series through measurement. In the case of the
resistive DUTs the S11 measured with 2 port (red blue dotted) is almost
identical with the S11 measured with 1 port (orange dotted). The same I
see
with the toroid DUT.
But I am not able to map the Zdut calculated with the S21 (green dashed;
measured in the series through 2 port).

So the Zdut (Zx) using with 2port series through and S11 based is
different
from Zdut (Zx) using (the same) 2 port series through and S21 based. So
all
stray capacitances, etc are the same (which I see part of the DUT).

All the best,

Victor

Op za 11 jun. 2022 om 07:26 schreef Roger Need via groups.io
<sailtamarack=
[email protected]>:

Victor,

I am not sure how you are measuring the DUT using S11 reflection and
S21
series methods.

You have to measure them with the correct reference plane calibration
and
this usually requires two different test jigs. What are you using for
S11
and S21 test jigs? Attached is one I use for S11 up to 30 MHz. I tack
solder the DUT as shown. My example uses an inductor but you can
solder
the leads to your choke. The second one I built into a box and it
works
well too. I posted my S21 series jig in the last topic

Roger
Re: adding Bluetooth HC-06 connection to plain - H hardware #bluetooth

 

Hi Vaclav,

Please type ¡°P3 uart¡± into the Search box in the upper right to help to identify this board level change.

Larry
AC9OX
Re: 2port measurement determining Zdut with S11 and S21

 

I forgot to add that the NanoVNA measured Impedance (based on the S21 (or
S11) 2port series through):
[image: afbeelding.png]
matches quite nicely the theoretical simulation of a choke:

[image: afbeelding.png]

<the theoretical simulation got one parameter (stray capacitance of the
choke, not of the testing gear!) which was derived by matching the peak in
the simulation with the peak in the measured S21 curve>

I think I am more or less understanding what/how is measured with the
NanoVNA. Will try to make a web page out of that.

All the best,

Victor



Op za 11 jun. 2022 om 08:32 schreef Victor Reijs via groups.io
<pe1atn.victor.reijs@...>:

Hello Roger,

Using Series though, the NanoVNA measures both a S11 and S21 (for that
configuration, which I [of course] calibrated). The link I gave (
), calculates the Zdut using
these Sx1 from the 2port series through measurement. In the case of the
resistive DUTs the S11 measured with 2 port (red blue dotted) is almost
identical with the S11 measured with 1 port (orange dotted). The same I see
with the toroid DUT.
But I am not able to map the Zdut calculated with the S21 (green dashed;
measured in the series through 2 port).

So the Zdut (Zx) using with 2port series through and S11 based is different
from Zdut (Zx) using (the same) 2 port series through and S21 based. So all
stray capacitances, etc are the same (which I see part of the DUT).

All the best,

Victor

Op za 11 jun. 2022 om 07:26 schreef Roger Need via groups.io
<sailtamarack=
[email protected]>:

Victor,

I am not sure how you are measuring the DUT using S11 reflection and S21
series methods.

You have to measure them with the correct reference plane calibration and
this usually requires two different test jigs. What are you using for
S11
and S21 test jigs? Attached is one I use for S11 up to 30 MHz. I tack
solder the DUT as shown. My example uses an inductor but you can solder
the leads to your choke. The second one I built into a box and it works
well too. I posted my S21 series jig in the last topic

Roger









afbeelding.png
afbeelding.png

Re: Off subject - nanoVNA forum no longer on Facebook #nanovna

Anne Ranch
 

Many years ago I made a BIG mistake by signing up with my real name. I get unwanted , unsolicited
e-mail addressed to that mail box.
I am opinionated and I do not pussy foot around issue , I tell how I feel.
If you watched George Carlin "shell shock " monologue you will know
that giving a same issue fancy name does not fix the issue.

Unfortunately a lot of "contributors" in forums concentrate on format
and not on resolving issuers.
And there is time honored management policy - to resolve an issue - fire the complainer...

end of rant
adding Bluetooth HC-06 connection to plain - H hardware #bluetooth

Anne Ranch
 

Could somebody just confirm that I am on the right track ?

I do not see "P3" - UART connector on my hardware.



PS
To the person who keeps removing my posts -
have some courtesy and at least say they to not meet forum standards
and I will quit wasting my time here.
Re: spreadsheet for importing snp files, Excel 2010

 

Thanks Rich, your spreadsheet also helped me to spur on some of my work.
Thanks for sharing!

All the best,

Victor

Op za 11 jun. 2022 om 21:41 schreef Rich NE1EE <TheDustyKey@...

:
Thanks for the comments to spur me on...I earlier felt that I had better
clean up the spreadsheet just to avoid more confusion, but never took the
time. Glad that it's turned out to be of some use. Wasna sure when I posted
it if anyone would be interested.
--
~R~
72/73 de Rich NE1EE
The Dusty Key
On the banks of the Piscataqua
Re: 2port measurement determining Zdut with S11 and S21

 

Thanks Roger and Owen,

Remember that the S11 formula from
and NanoVNA Saver (and my own
Excel spreadsheets) already takes away the 50ohm (Zload) of port 2.
The S11 2-port series through measurement (also described by k6jca,
NaonoVNA Saver and earlier link), is always close to the S11 1-port
measurement.

My calibration plane is at the end of the middle/earth tips of the PCB SMA
connector (also my calibration kit is at these tips:
). I solder the
DUT directly to these pins aka calibration plane (so no real extension of
the plane). This all to minimize variability of reference plane
capacitance/etc.

In my case Zload of port2 is very close to on average 50.8-0.1i ohm (300kHz
to 30MHz), which is based on a calibration load of 49.7 ohm (using DVM,
accuracy 1.5%). As my Calibration-load is a little smaller than 50~0iohm,
the resistances measured by the NanoVNA will be a little too high. So my
Zload comes closer to 50ohm. Anyway I compensate S21 for that Zload.
In my case Zsource is significantly different (on average 43.6+3.2iohm)
from 50ohm. So I compensate S21 for that (using Owen's method:
), S11 is not affected by this Zsource
as Zsource is calibrated 'out' by Calibration-load.

I put the DUT on a styrofoam underground (to minimize the effects of my
wooden table top's dielectricum). I also put a clip-on ferrite on the port1
or port2 wire, or shortened the port2 cable (from 16cm to 2cm), or put it
as far away from other equipment (the NanoVNA is though always some 16cm
nearby: IMG_1643.jpg). All these changes don't really have an effect on
2port series through measurements of S11 or S21. Only slightly at the end
of my measurement range (30MHz).
The DUT (in 2 port series through) has *certainly* hand effect (aka adding
stray capacitance), so I need to stay way;-). This hand effect is most
prominent on the S21 (not much on the S11) 2-port series through.

If I change the offset delay, this has almost no effect on S21 2port series
through (as expected), but on the S11 2port series through (it shifts the R
and X peaks to higher frequencies). If I put the offset delay to around
-56ps equivalent to 7.5mm, the R&X peaks of S11 map the R&X peaks of S21.
The below screengrab is with a offset delay of -56ps:
[image: afbeelding.png]
I still find it strange that while the S21 changes so much the S11 stays
quite constant. If I understand k6jca (


), he (as some other experts) likes S21 the best (also more stable than
S11...) for high impedances (like for chokes at say 10kohm). This makes it
even more confusing as others now tell me S11 is better;-)
It would be nice to use Benson's Y method; but that needs a S11, S21, S12,
S22 setup (and with that a 12-term calibration). This is not available with
NanoVNA, so that does not help as advice. Perhaps in a few years prices
will go down for such equipment;-)

I will digest k6jca pages in more detail (I recognise some of what he is
telling, looking at my own experiences).

Thanks for all the feedback provided. If I gain more experience, I will
communicate over the group.

All the best,

Victor

Op za 11 jun. 2022 om 20:08 schreef Roger Need via groups.io <sailtamarack=
[email protected]>:

Others have found similar issues using the S21 series method using the
NanoVNA and even with higher performance HP VNA equipment. Here are some
interesting links. The K6JCA experiments find differences similar to what
you have measured.






In my experiments I found that parasitic capacitance had considerable
affect on the S21 measurements and I tried several different test jigs to
see what happened. The issue of where to establish the reference plane
took some consideration. S21 Gain and S21 phase determine the complex
impedance of the DUT and even with some type of source (Port1) and
termination (Port2) correction the phase was often incorrect. Phase
measurement was the problem and in my tests was due to an offset delay
across the jig. Another issue I found was that for some reason high DUT
impedance resulted in common mode current on the surface of the coax cables
connecting the NanoVNA to the test jig. I tried snap-on ferrites and the
results changed.

You mentioned that you could do a S11 reflection and S21 series
measurement at the same time. You will get different results when the DUT
is in series between Port 1 and Port2 compared to when it is across Port 1
alone. Best case is that it will be 50 ohms higher. TIn reality the
complex impedance measured when in series is the DUT plus the input
impedance of the cable attached to Port 2 (which will deviate from 50 ohms
due to Port 2 impedance not being 50 ohms) and any parasitic inductance or
capacitance between the DUT and the Port 2 cable.

I wish you good luck in your quest and hope you find a method that works
for you and that you find a solution that eluded me.

afbeelding.png
IMG_1643.jpg

Re: spreadsheet for importing snp files, Excel 2010

 

Thanks for the comments to spur me on...I earlier felt that I had better clean up the spreadsheet just to avoid more confusion, but never took the time. Glad that it's turned out to be of some use. Wasna sure when I posted it if anyone would be interested.
--
~R~
72/73 de Rich NE1EE
The Dusty Key
On the banks of the Piscataqua
Re: 2port measurement determining Zdut with S11 and S21

 

On Sat, Jun 11, 2022 at 11:08 AM, Roger Need wrote:

In my experiments I found that parasitic capacitance had considerable affect
on the S21 measurements and I tried several different test jigs to see what
happened.
Here is one of theS11/S21 test jigs I tried. It could use improvement but I don't have the time right now to continue with this project.

Roger

S11 - S21 Test Jig.jpg

Re: Off subject - nanoVNA forum no longer on Facebook #nanovna

 

Hi Vaclav Sal,

I just went to ¡°FB Nano VBA and Tiny SA¡± and saw the messages that you had previously posted regarding your issues.

I believe that your choice to use the alias ¡°Anne Ranch¡± on various groups.io and FB might be the cause of your issues.

(Using Anne Ranch, AA7EJ on the linuxham group caused confusion.)

Hope that this helps.

Larry
AC9OX
Re: 2port measurement determining Zdut with S11 and S21

 

Victor,

Let me preface my comments by saying that I have built several test jigs for measuring impedance using the S21 series method and tried several ways to compensate for errors. None have been very successful and I now just use the S11 reflection method which works up to several thousand ohms of complex impedance with a decent test jig.

I believe the NanoVNA-H4 is just not the right tool for the job for several reasons that I have mentioned before....
- the source and termination impedances are not 50 + j0 ohms and vary with frequency
- the current firmware and PC programs only use 6 term error correction not 12 term

Others have found similar issues using the S21 series method using the NanoVNA and even with higher performance HP VNA equipment. Here are some interesting links. The K6JCA experiments find differences similar to what you have measured.




In my experiments I found that parasitic capacitance had considerable affect on the S21 measurements and I tried several different test jigs to see what happened. The issue of where to establish the reference plane took some consideration. S21 Gain and S21 phase determine the complex impedance of the DUT and even with some type of source (Port1) and termination (Port2) correction the phase was often incorrect. Phase measurement was the problem and in my tests was due to an offset delay across the jig. Another issue I found was that for some reason high DUT impedance resulted in common mode current on the surface of the coax cables connecting the NanoVNA to the test jig. I tried snap-on ferrites and the results changed.

You mentioned that you could do a S11 reflection and S21 series measurement at the same time. You will get different results when the DUT is in series between Port 1 and Port2 compared to when it is across Port 1 alone. Best case is that it will be 50 ohms higher. TIn reality the complex impedance measured when in series is the DUT plus the input impedance of the cable attached to Port 2 (which will deviate from 50 ohms due to Port 2 impedance not being 50 ohms) and any parasitic inductance or capacitance between the DUT and the Port 2 cable.

I wish you good luck in your quest and hope you find a method that works for you and that you find a solution that eluded me.

Roger
Re: 2port measurement determining Zdut with S11 and S21

 

Op za 11 jun. 2022 om 08:32 schreef Victor Reijs via groups.io
<pe1atn.victor.reijs@...>:

Hello Roger,

Using Series though, the NanoVNA measures both a S11 and S21 (for that
configuration, which I [of course] calibrated). The link I gave (
), calculates the Zdut using
these Sx1 from the 2port series through measurement.
By the way, NanoVNA Saver uses also these formulas to plot the S11 and S21
for the 2port series through measurements (Sx1 R+jX [series]). IMHO these
two should be quite the same, but they are in my case quite different (as
you could see in the earlier screen grab of NanoVNA Saver.

All the best,
Victor
Re: 2port measurement determining Zdut with S11 and S21

 

Hello Roger,

Using Series though, the NanoVNA measures both a S11 and S21 (for that
configuration, which I [of course] calibrated). The link I gave (
), calculates the Zdut using
these Sx1 from the 2port series through measurement. In the case of the
resistive DUTs the S11 measured with 2 port (red blue dotted) is almost
identical with the S11 measured with 1 port (orange dotted). The same I see
with the toroid DUT.
But I am not able to map the Zdut calculated with the S21 (green dashed;
measured in the series through 2 port).

So the Zdut (Zx) using with 2port series through and S11 based is different
from Zdut (Zx) using (the same) 2 port series through and S21 based. So all
stray capacitances, etc are the same (which I see part of the DUT).

All the best,

Victor

Op za 11 jun. 2022 om 07:26 schreef Roger Need via groups.io <sailtamarack=
[email protected]>:

Victor,

I am not sure how you are measuring the DUT using S11 reflection and S21
series methods.

You have to measure them with the correct reference plane calibration and
this usually requires two different test jigs. What are you using for S11
and S21 test jigs? Attached is one I use for S11 up to 30 MHz. I tack
solder the DUT as shown. My example uses an inductor but you can solder
the leads to your choke. The second one I built into a box and it works
well too. I posted my S21 series jig in the last topic

Roger
Re: 2port measurement determining Zdut with S11 and S21

 

Victor,

I am not sure how you are measuring the DUT using S11 reflection and S21 series methods.

You have to measure them with the correct reference plane calibration and this usually requires two different test jigs. What are you using for S11 and S21 test jigs? Attached is one I use for S11 up to 30 MHz. I tack solder the DUT as shown. My example uses an inductor but you can solder the leads to your choke. The second one I built into a box and it works well too. I posted my S21 series jig in the last topic

Roger

Banana post adapter.jpg
Banana Box FB small.png

Re: #firmware NanoVNA SAA-2N firmware not loading #firmware

 

Glad you solved it, and sorry I did not reply earlier . . . we were out for the evening . . .

On June 10, 2022 8:02:34 PM CDT, Robert Coleman <rcoleman@...> wrote:
Ahoy, Belay my last.... I found my way and cleared out the incorrect firmware. It took much searching thru many messages plus wiggling the usb plug. But now I have the version git-20201013-32077fd loaded and the vna is happy. Thanks to those with suggestions and for the searchable history of this group. Now for a shot at calibration.....but first to buy a quality usb-3 cable.
--
72/73 de k1qed, ?bob.c ? ? ? ? qrp 4evr!




--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: #firmware NanoVNA SAA-2N firmware not loading #firmware

 

Ahoy, Belay my last.... I found my way and cleared out the incorrect firmware. It took much searching thru many messages plus wiggling the usb plug. But now I have the version git-20201013-32077fd loaded and the vna is happy. Thanks to those with suggestions and for the searchable history of this group. Now for a shot at calibration.....but first to buy a quality usb-3 cable.
--
72/73 de k1qed, ?bob.c ? ? ? ? qrp 4evr!
Re: spreadsheet for importing snp files, Excel 2010

 

Hi Rich:

Thanks for the correction.
You are absolutely correct as presented, .016 for this leads one to the 35.917 dB answer

And your cell was L4 not M4.

Glad confusion removed on final version.

Enjoyed the Pisacataqua discourse: fastest tidal flowing river in the US, if I correctly recall. Big moon tide took out the tree supporting my antenna end, and headed to Kittery.

Ed McCann
AG6CX
11741 - 11760 of 39614