Don Brant sent me an .s2p file to help test my plotter. It's for an amplifier with several feet of cabling. When I looked at the phase response, I knew I had found a new poster child for the virtues of phase unwrapping.
Brian
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Re: nano vna h black screen
Device manager just tells me best driver is already installed but all i get is stm bootloader showing up in USB devices
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Show quoted text
On Mar 2, 2025, at 4:27?PM, Bob Gauthier <bobgau@...> wrote:
?Thanks for the reply, nowhere on the board do i see any reference to ms,si or zk, where should i be looking? Also have installed dfuse demo but running cannot get the correct driver. Looked in the files section and on stm site but cannot find a driver for win 11.
On Mar 2, 2025, at 3:06?PM, juancb via groups.io <juancb@...> wrote:
?What firmware are you trying to use?
If you are using Hugen79's firmware then pay close attention to the image you downloaded. I ran into a black screen after upgrade as well caused by me mistakingly flashing my NanoVNA-H4 with the -H firmware. The H and H4 are different hardware and their firmware is incompatible. Furthermore check the back of your unit and make sure you've selected the right hardware variant of the H (MS, SI, ZK) not doing so will also result in a failure to boot.
Luckily recovering is easy, just boot into DFU mode and flash the right firmware for your H/H4. I hope that helps.
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Re: nano vna h black screen
Thanks for the reply, nowhere on the board do i see any reference to ms,si or zk, where should i be looking? Also have installed dfuse demo but running cannot get the correct driver. Looked in the files section and on stm site but cannot find a driver for win 11.
toggle quoted message
Show quoted text
On Mar 2, 2025, at 3:06?PM, juancb via groups.io <juancb@...> wrote:
?What firmware are you trying to use?
If you are using Hugen79's firmware then pay close attention to the image you downloaded. I ran into a black screen after upgrade as well caused by me mistakingly flashing my NanoVNA-H4 with the -H firmware. The H and H4 are different hardware and their firmware is incompatible. Furthermore check the back of your unit and make sure you've selected the right hardware variant of the H (MS, SI, ZK) not doing so will also result in a failure to boot.
Luckily recovering is easy, just boot into DFU mode and flash the right firmware for your H/H4. I hope that helps.
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Re: nano vna h black screen
What firmware are you trying to use?
If you are using Hugen79's firmware then pay close attention to the image you downloaded. I ran into a black screen after upgrade as well caused by me mistakingly flashing my NanoVNA-H4 with the -H firmware. The H and H4 are different hardware and their firmware is incompatible. Furthermore check the back of your unit and make sure you've selected the right hardware variant of the H (MS, SI, ZK) not doing so will also result in a failure to boot.
Luckily recovering is easy, just boot into DFU mode and flash the right firmware for your H/H4. I hope that helps.
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Re: nano vna h black screen
reply. Much appreciated
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On Mar 2, 2025, at 9:59?AM, VA4BG via groups.io <bobgau@...> wrote:
?I should have included in main body instead of just a lower case h in subject line, my apologies for poor description. Pic attached from board, thank you for the
On Mar 2, 2025, at 9:23?AM, Siegfried Jackstien via groups.io <siegfried.jackstien@...> wrote:
?shoot in the dark .. a nano vna H ??
dg9bfc sigi
Am 02.03.2025 um 16:21 schrieb Tim Dawson: Telling us what model Nano-VNA you have would be a good starting point.
On March 1, 2025 11:12:20 PM EST, "VA4BG via groups.io" <bobgau@...> wrote:
problem started when i attempted to upgrade, screen went black, foolishly did not save the old version.. now i can read the vna with stm32, it even appears to write the new firmware but still a black screen, how do i know if i am using the correct firmware for my vna? what are the correct steps to read and program with stm32? i must be missing something, any help would be appreciated.
thanks for any advice
Bob
VA4BG
<image0.jpeg>
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Re: nano vna h black screen
I should have included in main body instead of just a lower case h in subject line, my apologies for poor description. Pic attached from board, thank you for the
toggle quoted message
Show quoted text
On Mar 2, 2025, at 9:23?AM, Siegfried Jackstien via groups.io <siegfried.jackstien@...> wrote:
?shoot in the dark .. a nano vna H ??
dg9bfc sigi
Am 02.03.2025 um 16:21 schrieb Tim Dawson:
Telling us what model Nano-VNA you have would be a good starting point.
On March 1, 2025 11:12:20 PM EST, "VA4BG via groups.io" <bobgau@...> wrote:
problem started when i attempted to upgrade, screen went black, foolishly did not save the old version.. now i can read the vna with stm32, it even appears to write the new firmware but still a black screen, how do i know if i am using the correct firmware for my vna? what are the correct steps to read and program with stm32? i must be missing something, any help would be appreciated.
thanks for any advice
Bob
VA4BG
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Re: nano vna h black screen
shoot in the dark .. a nano vna H ??
dg9bfc sigi
Am 02.03.2025 um 16:21 schrieb Tim Dawson:
toggle quoted message
Show quoted text
Telling us what model Nano-VNA you have would be a good starting point.
On March 1, 2025 11:12:20 PM EST, "VA4BG via groups.io" <bobgau@...> wrote:
problem started when i attempted to upgrade, screen went black, foolishly did not save the old version.. now i can read the vna with stm32, it even appears to write the new firmware but still a black screen, how do i know if i am using the correct firmware for my vna? what are the correct steps to read and program with stm32? i must be missing something, any help would be appreciated.
thanks for any advice
Bob
VA4BG
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Re: nano vna h black screen
Telling us what model Nano-VNA you have would be a good starting point.
toggle quoted message
Show quoted text
On March 1, 2025 11:12:20 PM EST, "VA4BG via groups.io" <bobgau@...> wrote: problem started when i attempted to upgrade, screen went black, foolishly did not save the old version.. now i can read the vna with stm32, it even appears to write the new firmware but still a black screen, how do i know if i am using the correct firmware for my vna? what are the correct steps to read and program with stm32? i must be missing something, any help would be appreciated.
thanks for any advice
Bob
VA4BG
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
|
problem started when i attempted to upgrade, screen went black, foolishly did not save the old version.. now i can read the vna with stm32, it even appears to write the new firmware but still a black screen, how do i know if i am using the correct firmware for my vna? what are the correct steps to read and program with stm32? i must be missing something, any help would be appreciated.
thanks for any advice
Bob
VA4BG
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Re: High impedance measurement with VNA?
Jim, thank you a lot for the detailed information. I will be able to do some surgery on one of the NanoVna gen111.taobao.com firmware, which I updated to 0.3.0m. I will have to check the schematics for it.
Not that I want to deviate to much for the topic of measuring high impedance of vertical, but to bring back a way to update the old technologies like the OIB meter.
"Is there a reason you need high power for the test?"
When you are one of those blessed with a 50KW AM BC nearby and trying to measure the Z of a top hat loaded vertical or inverted V seems a bit of a challenge. After filtering the BC station a lot, I end up with a 10Watts at the end of the feed. Seems like I need some power to fight back.
Patty.
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Re: High impedance measurement with VNA?
The NanoVNA doesn't have a separate Source and receiver ports, so you can't do the external amplifier, coupler approach in the Rackley paper.
Is there a reason you need high power for the test? (that is, can't you just push the mighty milliwatt from the VNA into the antenna)
What you might be able to do is sequentially make S21 measurements, switching the second port (CH1) of the NanoVNA to the various ports of the directional coupler (with attenuators as required). The challenge is that the power amplifier will be "outside the calibration plane", so you'd need to separately characterize it and then do the math to remove its contribution. A complication is that the PA's characteristics probably change with the load impedance.
The techniques in the paper rely on having multiple coherent receivers that are separately accessible, which the NanoVNA doesn't have - two of the three receivers are "dedicated".
Now it's true that you could probably go in and do some surgery on a NanoVNA (they're inexpensive, and you're collecting data into a computer, so you could get the one with the small display) and bring out the different ports you need. (basically, the inputs to the mixers fed from the stimulus, and the bridge on CH0) - you could replace the circuitry with a little board with the same input circuit that CH1 has (which is, I believe, a resistive pad and some coupling capacitors).
You could then use software (Scikit-rf in python for instance, has the libraries) to do the calibrations, etc.; using the modified NanoVNA just as a data collector.
Another approach would be to build up an equivalent system using some inexpensive SDRs all locked to a common reference - A programmable source (the NanoVNA) and 3 or 4 RTL-SDRs might work
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-----Original Message----- From: < [email protected]> Sent: Mar 1, 2025 9:22 AM To: < [email protected]> Subject: Re: [nanovna-users] High impedance measurement with VNA? From amfone :;wap2 John K5PRO: Before the days of plastic antenna analyzers, you either used a GR bridge or a slotted line (for VHF), or just knew the SWR from a cheap wattmeter or Bird, or if you were lucky, a Delta OIB-2. This is the cousin of the famous OIB-1 and OIB-3 used by by broadcast engineers. Freq range is 2-30 MHz, 1 kW thru-power. Reads +/- 500 ohms resistive and up to +/- 800 ohms of reactance, and includes the meter amplifier for precise null And the modern version using a Hp8753C with a DIY directional coupler , 2 Attenuators , and RF amplifier: Newbie as I am on NanoVna , it will be beneficial if some can suggest how to use the NanoVna to achieve OIB measurements like the ones mentioned on the paper
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Re: High impedance measurement with VNA?
The NanoVNA doesn't have a separate Source and receiver ports, so you can't do the external amplifier, coupler approach in the Rackley paper.
Is there a reason you need high power for the test? (that is, can't you just push the mighty milliwatt from the VNA into the antenna)
What you might be able to do is sequentially make S21 measurements, switching the second port (CH1) of the NanoVNA to the various ports of the directional coupler (with attenuators as required). The challenge is that the power amplifier will be "outside the calibration plane", so you'd need to separately characterize it and then do the math to remove its contribution. A complication is that the PA's characteristics probably change with the load impedance.
The techniques in the paper rely on having multiple coherent receivers that are separately accessible, which the NanoVNA doesn't have - two of the three receivers are "dedicated".
Now it's true that you could probably go in and do some surgery on a NanoVNA (they're inexpensive, and you're collecting data into a computer, so you could get the one with the small display) and bring out the different ports you need. (basically, the inputs to the mixers fed from the stimulus, and the bridge on CH0) - you could replace the circuitry with a little board with the same input circuit that CH1 has (which is, I believe, a resistive pad and some coupling capacitors).
You could then use software (Scikit-rf in python for instance, has the libraries) to do the calibrations, etc.; using the modified NanoVNA just as a data collector.
Another approach would be to build up an equivalent system using some inexpensive SDRs all locked to a common reference - A programmable source (the NanoVNA) and 3 or 4 RTL-SDRs might work
toggle quoted message
Show quoted text
-----Original Message----- From: < [email protected]> Sent: Mar 1, 2025 9:22 AM To: < [email protected]> Subject: Re: [nanovna-users] High impedance measurement with VNA? From amfone :;wap2 John K5PRO: Before the days of plastic antenna analyzers, you either used a GR bridge or a slotted line (for VHF), or just knew the SWR from a cheap wattmeter or Bird, or if you were lucky, a Delta OIB-2. This is the cousin of the famous OIB-1 and OIB-3 used by by broadcast engineers. Freq range is 2-30 MHz, 1 kW thru-power. Reads +/- 500 ohms resistive and up to +/- 800 ohms of reactance, and includes the meter amplifier for precise null And the modern version using a Hp8753C with a DIY directional coupler , 2 Attenuators , and RF amplifier: Newbie as I am on NanoVna , it will be beneficial if some can suggest how to use the NanoVna to achieve OIB measurements like the ones mentioned on the paper
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Re: High impedance measurement with VNA?
From amfone :;wap2
John K5PRO:
Before the days of plastic antenna analyzers, you either used a GR bridge or a slotted line (for VHF), or just knew the SWR from a cheap wattmeter or Bird, or if you were lucky, a Delta OIB-2. This is the cousin of the famous OIB-1 and OIB-3 used by by broadcast engineers. Freq range is 2-30 MHz, 1 kW thru-power. Reads +/- 500 ohms resistive and up to +/- 800 ohms of reactance, and includes the meter amplifier for precise null
And the modern version using a Hp8753C with a DIY directional coupler , 2 Attenuators , and RF amplifier:
Newbie as I am on NanoVna , it will be beneficial if some can suggest how to use the NanoVna to achieve OIB measurements like the ones mentioned on the paper
|
Re: High impedance measurement with VNA?
Thanks Jim, now I understand better.
So, I will build a LC tuning circuit and I will measure afterwards to adjust it.
--
73 s Christian F8GHE
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I've added impedance measurements to the S-parameter plotter. It now includes the one-port reflection method and the two-port series-through, shunt-through, and Y21 methods. Y21 cancels stray port reactance. The plotter includes reference impedance renormalization. You can measure a component at 50 ohms and see the response at its design impedance. I include a utility to merge files for forward and reverse S11 and S21 measurements to obtain S11, S21, S12, and S22. This lets you use a NanoVNA to fully characterize a component that may have an asymmetrical response, such as a ceramic filter.
The program is at the top of the following page. See the bottom of the page for downloading instructions.
Brian
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Re: Am I in the right track ?
Roger,
Thanks. I thought I had replied yesterday but apparently not. Well, let me shop some 0603 resistors and ferrites and I'll come back once I get something decent.
Also, my board is scrap.
1- I chose the wrong construction material when I ordered.
2- My transmission line does not have a proper return path. The strip on the next layer is way too narrow.
3- I need to remove those square pads at the antenna base points, they are for the surface mount version of this antenna.
3- My ground plane is 74mm long, as per datasheet, this should be 84mm
Perseverance, the first quality I teach my son... I'm too far in, I'll get to the end :)
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Re: High impedance measurement with VNA?
Some of those techniques are more about measuring a high impedance component, so they wouldn’t work.
You’re making an S11 measurement - it’s just challenging because for end fed antennas, there’s more to the antenna than the wire you’re at the end of.
It’s the same as trying to measure the Z of a top hat loaded vertical or a vertical of any kind - where does the “other terminal” connect?
In the case of an end fed, the “other half of the antennna” is often the feed line.
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On Feb 26, 2025, at 12:02, Christian BARTHOD F8GHE via groups.io <cbarthod@...> wrote:
?
Jim thanks very much for your advise.
During this afternoon I found these urls and now I don't know what is the best way to measure my end-feed antenna : Your or one of these :
-
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-
--
73 s Christian F8GHE
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Re: High impedance measurement with VNA?
Jim thanks very much for your advise.
During this afternoon I found these urls and now I don't know what is the best way to measure my end-feed antenna : Your or one of these :
-
-
-
--
73 s Christian F8GHE
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Re: My NanoVNA-H4 is bricked. Is there a manual internal switch to reset?
Also ensure that the cable that you are using is a data cable and not just one capable of only supplying power. Many cables can only supply power unless specifically stated, so I use a cable tester to make sure that it is capable of data. The one supplied with your device should be a data cable as long as you got it from a reputable seller. <> Virus-free.www.avast.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Wed, Feb 26, 2025 at 7:41?PM Roger Need via groups.io <sailtamarack= [email protected]> wrote: On Wed, Feb 26, 2025 at 10:52 AM, Len Ward wrote:
Mine is not seen by Win 10 device manager. ( tried 2 cables and
machines) I
heard there is a way to get it out of DFU mode internally?
Mine did not die updating firmware, but it was hooked up to PC using "saver"
program I think.
I installed the dfu se demo and file manager, but it's useless since PC can't
see the device
NanoVNA Saver does not touch your firmware so it could not have damaged
your device. Your device cannot be "bricked" because the DFU loader is
built into ROM on the microprocessor.
Does your device boot at all or is it just a black or white screen? Can
you talk to it using the USB COM port and a serial program like Putty?
To get the H4 device into DFU mode you can do one of the following:
- Select DFU from the menu
- Push the jog switch down with the power off and then power on
- Open the case and short the VDD and Boot0 pins, then power on and remove
the short
When you do one of the above and are connected to a Windows PC you should
hear a "bing" in Windows. If you go into Device Manager you should see
that your device is recognized. One of two drivers will be installed. One
works with DFUse and nanoVNA app for firmware loading and the other works
with STM Cube. You can search this group and the group Wiki for the many
messages on how to install drivers and use these programs.
Also suggest you read the Absolute Beginners Guide to the NanoVNA in the
Files section of this group.
Roger
Roger
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Re: My NanoVNA-H4 is bricked. Is there a manual internal switch to reset?
On Wed, Feb 26, 2025 at 10:52 AM, Len Ward wrote:
Mine is not seen by Win 10 device manager. ( tried 2 cables and machines) I
heard there is a way to get it out of DFU mode internally?
Mine did not die updating firmware, but it was hooked up to PC using "saver"
program I think.
I installed the dfu se demo and file manager, but it's useless since PC can't
see the device
NanoVNA Saver does not touch your firmware so it could not have damaged your device. Your device cannot be "bricked" because the DFU loader is built into ROM on the microprocessor. Does your device boot at all or is it just a black or white screen? Can you talk to it using the USB COM port and a serial program like Putty? To get the H4 device into DFU mode you can do one of the following: - Select DFU from the menu - Push the jog switch down with the power off and then power on - Open the case and short the VDD and Boot0 pins, then power on and remove the short When you do one of the above and are connected to a Windows PC you should hear a "bing" in Windows. If you go into Device Manager you should see that your device is recognized. One of two drivers will be installed. One works with DFUse and nanoVNA app for firmware loading and the other works with STM Cube. You can search this group and the group Wiki for the many messages on how to install drivers and use these programs. Also suggest you read the Absolute Beginners Guide to the NanoVNA in the Files section of this group. Roger Roger
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VA4BG
Christian BARTHOD F8GHE
Roger Need