Re: After firmware update my nano-vna-h is behaving bizarrely.
Yep...Just went through this myself. Mine was an MS version and dislord 1.2.40 defaults to SI.
Bryan, n0luf
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Re: NanoVNA port renormalization
Second try on screenshots:
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Re: NanoVNA port renormalization
Roger,
Here are screenshots of tests with a ceramic filter and a crystal filter at 10.7 MHz (different spans).
Each is shown at 50 ohms and again at a higher Z that gives a better match.
Also shown is the test fixture and the filters I tested. There is no matching added to the fixture, just direct connections with coax leads about 3cm long. The small headers on the test fixture are the 50 ohm and short used in calibration. Not shown in the photo is the thru jumper.
--John
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On Sun, Feb 9, 2025 at 02:40 PM, Roger Need wrote:
On Sun, Feb 9, 2025 at 02:04 PM, John Gord wrote:
A crystal (or ceramic) filter response is correctly transformed by the
renormalization; I have used this feature several times.
Interesting... What was the design impedance of the filter?
I am surprised at your results because the loading greatly affects the crystal
filter characteristics. The usual way is to use a series resistance, L pad or
transformer on input and output if the crystal filter is designed for a higher
impedance and then recalculate the response from the measured results
factoring this in. Doing this is not the same as directly connecting a 50
ohms VNA and then doing a S parameter transformation (Port Z function) like
the one in the NanoVNA. I am interested in your results so please explain
the test setup and your results.
Roger
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Re: Smith Chart acting up in calibration
As a followup on this, I see the chip specific files from Huygen, but not Dislord . . . . fwiw . . .
- Tim
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On February 9, 2025 8:41:26 PM EST, Tim Dawson <tadawson@...> wrote: At one time there were specific binaries which set that flag (but otherwise identical) Not sure if they still exist or not, since it's so easy to set.
- Tim
On February 9, 2025 8:26:04 PM EST, "Bryan Curl via groups.io" <bc3910@...> wrote:
Absolutely....thanks Tim. Somehow I missed your post.
One thing Ill have to remember now is that a reset will revert it back to SI...even if I save the config.
Fred, Yes, the sma connectors are weak sauce. They are always my first suspect. My next one may have N type...but adapters may cost more than the nanovna. hi hi.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Re: NanoVNA port renormalization
Hi
This is my point of view : Z--> option does not change the physically pot2 impedance , it remaine always at 50 Ohm +/- 1 ohm value, just firmware by computing way can display S11 or S21 as its at 75 ohm or 300 ohm , for example seting it at the accurate physically port2 50.45 ohm will gives more accurate S11 S21 displayed results , but if DUT does not run smoothly on physically 50 Ohm load , computing compensation will loos sens , so its rather to have the two Z port option one for port1 and second for port2 .
73s Nizar.
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Re: After firmware update my nano-vna-h is behaving bizarrely.
If your nanovna-H is an MS version (rather than older SI version - see label on back for hardware revision number) - then you need to go into 'expert settings' and change the 'mode' to 'MS5351', then do 'save config'.
See if that is the problem.
Stan KC7XE
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After firmware update my nano-vna-h is behaving bizarrely.
After calibrating after upgrading to new firmware NanoVNA-H.v1.2.40.dfu from dsilord, the nano vna is showing what seems to be crazy flickering SWR values even after recalibrating and trying to find any setup that needs to be repeated.
Is this a known thing? Is it indicative that my device, labelled Nano-VNA-H and running a slightly earlier DSILord 1.2.x (1.2.30 I think) should go back to 1.2.30?
Warren VA7 WPX
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Re: Smith Chart acting up in calibration
At one time there were specific binaries which set that flag (but otherwise identical) Not sure if they still exist or not, since it's so easy to set.
- Tim
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On February 9, 2025 8:26:04 PM EST, "Bryan Curl via groups.io" <bc3910@...> wrote: Absolutely....thanks Tim. Somehow I missed your post.
One thing Ill have to remember now is that a reset will revert it back to SI...even if I save the config.
Fred, Yes, the sma connectors are weak sauce. They are always my first suspect. My next one may have N type...but adapters may cost more than the nanovna. hi hi.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Re: Smith Chart acting up in calibration
Absolutely....thanks Tim. Somehow I missed your post.
One thing Ill have to remember now is that a reset will revert it back to SI...even if I save the config.
Fred, Yes, the sma connectors are weak sauce. They are always my first suspect. My next one may have N type...but adapters may cost more than the nanovna. hi hi.
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Re: Nanovna-h and Windows 11
On Sun, Feb 9, 2025 at 11:18 AM, Stan Dye wrote:
Please see the detailed steps I provided for getting the correct driver
installed in the .pdf file at the following link. This is in the files section
of this group. Let me know if it doesn't clearly explain the solution, and
I'll update it:
/g/nanovna-users/files/Miscellaneous/DFU-mode%20Driver%20for%20Win10Win11
Stan KC7XE
I have been using the STM32 Cube Programmer (latest is now 2.19). Thanks so much for the docs and driver so I can now switch back and forth. I'm so used to the STM32 way but it's nice to be able to use the NanoVNA-App as well.
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Re: Smith Chart acting up in calibration
Thanks for the shout out, and glad that I could help!
- Tim
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On February 9, 2025 2:41:19 PM EST, "Roger Need via groups.io" <sailtamarack@...> wrote: On Sun, Feb 9, 2025 at 10:34 AM, Bryan Curl wrote:
Roger,
Resolved: You nailed the issue. I thought for sure I was an SI type but sure
enough the HW version is 4.3_MS. The flash changed it to SI.
Bryan - The first one to suggest this was Tim Dawson so he gets the credit not me...
Roger
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Re: NanoVNA port renormalization
On Sun, Feb 9, 2025 at 02:04 PM, John Gord wrote:
A crystal (or ceramic) filter response is correctly transformed by the
renormalization; I have used this feature several times.
Interesting... What was the design impedance of the filter? I am surprised at your results because the loading greatly affects the crystal filter characteristics. The usual way is to use a series resistance, L pad or transformer on input and output if the crystal filter is designed for a higher impedance and then recalculate the response from the measured results factoring this in. Doing this is not the same as directly connecting a 50 ohms VNA and then doing a S parameter transformation (Port Z function) like the one in the NanoVNA. I am interested in your results so please explain the test setup and your results. Roger
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Re: NanoVNA port renormalization
Roger,
Most filters are passive and linear.
A crystal (or ceramic) filter response is correctly transformed by the renormalization; I have used this feature several times.
I agree that an active circuit might not be stable if presented with 50 ohm loading when designed for another impedance.
The basic idea is that a passive two-port can be fully represented in a number of different ways like Z-parameters, Y-parameters, H-parameters and S-parameters normalized to various impedances. There are formulas to convert from one parameter type to another.
--John Gord
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On Sun, Feb 9, 2025 at 10:40 AM, Roger Need wrote:
On Sun, Feb 9, 2025 at 01:23 AM, DiSlord wrote:
Here is renormalization in coppermountaintech
Analysis > Fixture Simulator > Port Z Conversion
(z)-c.html
Unfortunately the link you provided was cutoff and did not work. Hopefully
groups.io formats this one correctly...
(z)-c.html
Copper mountain Provides for several Fixture Simulations. Here is the link to
the topic.
The current Port Z function in the NanoVNA changes the reference impedance
using only the real part with imaginary set to zero.. The measurement is
still made using 50 ohms on Port 1 (CH0) and Port 2 (CH1) and a mathematical
conversion of the matrix of S-parameters measured at 50 ohms to the matrix of
S-parameters with a reference impedance entered by the user is generated. In
my opinion there is a limitation to this method in that the DUT is being
driven and loaded by 50 ohms and that only linear passive devices will yield
correct results. Non linear devices or active circuits will not be tested
with the impedance they are designed to operate with and simulation using this
method will not yield correct results. So a 300 ohm resistive attenuator
would measure OK but a crystal filter circuit that was not designed to work in
a 50 ohm system would not.
Roger
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Re: NanoVNA port renormalization
On Sun, Feb 9, 2025 at 11:45 AM, Tony Scaminaci wrote:
Both the link DiSlord provided and your original link work fine for me. It
may be your email provider chopping up the link.
Thanks -- I don't get the emails from this group. I just log into the Web site for groups.io. It may be the way it formats on the Web. Roger
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Re: Nanovna-h and Windows 11
Hi Stan,
Shortsightedness on my part and I hadn't looked well enough and found your instructions which worked perfectly, thank you ever so much, Pete
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Re: NanoVNA port renormalization
Roger, Both the link DiSlord provided and your original link work fine for me. It may be your email provider chopping up the link. Tony On Sun, Feb 9, 2025 at 12:45?PM Roger Need via groups.io <sailtamarack= [email protected]> wrote: On Sun, Feb 9, 2025 at 10:40 AM, Roger Need wrote:
Unfortunately the link you provided was cutoff and did not work.
Hopefully
groups.io formats this one correctly...
(z)-c.html
Groups.io cutoff my link as well. Here is another attempt...
Roger
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Re: Smith Chart acting up in calibration
On Sun, Feb 9, 2025 at 10:34 AM, Bryan Curl wrote:
Roger,
Resolved: You nailed the issue. I thought for sure I was an SI type but sure
enough the HW version is 4.3_MS. The flash changed it to SI.
Bryan - The first one to suggest this was Tim Dawson so he gets the credit not me... Roger
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Re: Smith Chart acting up in calibration
Just a crazy thought from someone with very little VNA experience .....
SMA connectors are known to have a quite limited number of insertion cycles.
Is it possible you have a connector that is no longer working reliably;y?
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Re: Nanovna-h and Windows 11
Pete, you are having a driver problem. Windows11 has the most recent driver from ST, so it thinks it is the best one to use, and doesn't try to install the older driver that works with DfuseDemo and nanovna-app. (This driver does work with the latest STMCubeProgrammer from st.com.) Please see the detailed steps I provided for getting the correct driver installed in the .pdf file at the following link. This is in the files section of this group. Let me know if it doesn't clearly explain the solution, and I'll update it: /g/nanovna-users/files/Miscellaneous/DFU-mode%20Driver%20for%20Win10Win11Stan KC7XE
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For the HR'ers in the group, the H4 seems most popular. But get the LARGE SCREEN choice of any of them. Dave - W?LEV <> Virus-free.www.avg.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Sun, Feb 9, 2025 at 2:20?PM CLIFTON HEAD via groups.io <aecret= [email protected]> wrote: For a newie using wanting to use NanoVNA which is better the NanoVNA F V2
or the H4
-- *Dave - W?LEV* -- Dave - W?LEV
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VA7WPX_Warren
Roger Need
Fred, W9KEY