Re: Nano VNA F PC interface trouble (probably caused by operator error)
My NanoVNA-H uses one Windows driver for a standard serial interface and a different driver when updating firmware. The NanoVNA-H uses the STMicroelectronics Controller.
The standard serial interface runs with Microsoft Driver usbser.sys. No driver installation was required on my Windows 10 computer to run NanoVNA Saver. The Windows Device Manager shows a Virtual COM Port under Ports. The NanoVNA needs to be turned on.
Firmware is updated using DFU (Device Firmware Upgrade) which is a Device Class in the USB specification. The Windows Device Manager in my system displays "STM Device in DFU Mode" under USB Controllers after the connection is made. The actual driver is sttub30.sys.
See the Absolute Beginner's Guide to NanoVNA in the F?iles section for more details.
73, Kent
AA6P
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Re: Comparison Testing of Three Ferrite Beads using the Smith Chart
Thanks all for the help and confirming my understanding. It did appear that Bead 1 provided the largest increase in impedance consisting of a small real component and a somewhat larger amount of inductive reactance.
Ferrite 1 is Mix 43 from Fair-Rite Products. The composition of the other two beads is unknown. However, bead 3 looks like a powdered iron toroid intended for use as an inductor.
The selected bead will actually be used at higher frequencies. I wanted to simplify the discussion with data taken at 2 MHz where lead length might not be an issue.
I have one of the IC-706MKIIg transceivers with a self-oscillation problem on the 15 meter and 17 meter bands. There is a fix involving a ferrite bead on a small coaxial cable between the Filter board and Main board.
I initially placed Bead 2 and Bead 3 over the cable and the self-oscillation problem was no longer seen. It seemed like a good idea to order a few ferrite beads designed for HF suppression such as the relatively new Mix 31. I was not able to find the required size in Mix 31 and decided to order Mix 43 which had been an industry standard for many years.
The objective was to replace the unknown beads with two new beads that would hopefully provide additional attenuation and margin on the self-oscillation problem. I did test the three beads at higher frequencies and the relationship appeared to remain the same.
73, Kent
AA6P
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Re: Nano VNA F PC interface trouble (probably caused by operator error)
Hi, If you don¡¯t get enough help here, your device also has its own group. Please log in where you can also contact the manufacturer with your question. Link: /g/nanovna-f/topics 73, Gyula HA3HZ -- *** If you are not part of the solution, then you are the problem. ( ) ***
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Re: Nano vna-qt program error in ubunto linux
On 4/12/21 10:19 AM, Frank Worm wrote: Hello All
I am trying to get vna-qt program in linux to connect to my SAA2.
I have loaded the software into my win 10 machine and it works fine with the vna.
I have vna-qt running in ubunto linux but when I try to connect to it, it gives me an error message dialog box which reads:
"Exception
Permission denied"
Any ideas what may be wrong?
Thanks in advance.
Cheers Example for $ls -al /dev/tty* crw--w---- 1 root tty?????? 4,? 8 Nov? 8 08:17 /dev/tty8 crw--w---- 1 root tty?????? 4,? 9 Nov? 8 08:17 /dev/tty9 crw-rw---- 1 root dialout 204, 64 Nov? 8 08:38 /dev/ttyAMA0 crw------- 1 root root????? 5,? 3 Nov? 8 08:17 /dev/ttyprintk
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Re: Nano vna-qt program error in ubunto linux
On 4/12/21 10:19 AM, Frank Worm wrote: Hello All
I am trying to get vna-qt program in linux to connect to my SAA2.
I have loaded the software into my win 10 machine and it works fine with the vna.
I have vna-qt running in ubunto linux but when I try to connect to it, it gives me an error message dialog box which reads:
"Exception
Permission denied"
Any ideas what may be wrong?
Thanks in advance.
Cheers Is the username (you are logged in as) a member of the "dialout" group? If you look at /dev/ you can probably find it, and see the permissions for the comm port.? Typically, serial ports (and emulations thereof) are "owned" by dialout.? The default permissions on /dev/tty{whatever} are read for everyone, rw for the group. you can also run python as superuser (sudo python nanovna_saver)
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Nano vna-qt program error in ubunto linux
Hello All
I am trying to get vna-qt program in linux to connect to my SAA2.
I have loaded the software into my win 10 machine and it works fine with the vna.
I have vna-qt running in ubunto linux but when I try to connect to it, it gives me an error message dialog box which reads:
"Exception
Permission denied"
Any ideas what may be wrong?
Thanks in advance.
Cheers
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Re: Nano VNA F PC interface trouble (probably caused by operator error)
Make sure your device is turned on. When you plug it into windows 10 machine, does the plug-and-play capability recognize the device (it shows up in the device manager)?
Once that happens, then start your software and see if the device shows up in the com port location.
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Hi Joe,
Okay, this is from the first production.
Be sure to remove the cover, because if the touch screen is pressed anywhere, it will not work properly.
Although other mistakes are possible, invisibly this should be done first. It is not easy to repair a device remotely, so we are just guessing about possible errors so far.
If the fault disappears after removing the cover, it is recommended to place a plastic washer on the screw towers of the plastic housing (4 pcs.).
If it still does not work, check the LCD flexible cord carefully for a break somewhere. The cord goes into a connector, there may be no normal contact.
Here you can find more information about possible errors in the forum. Use the 'Search' button.
When you remove the cover, try calibrating the touch screen. Be sure to mark the outermost points as possible and then save the status. If a touch screen error is found, replace it with the current one firmware, because larger screen applications work with them correctly.
Read more on my web page as well.
I am confident that the problem will be solved.
If there is no mechanical damage, these are repairable defects.
73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***
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Re: Comparison Testing of Three Ferrite Beads using the Smith Chart
Of those three cores, obviously #1 is the material most suitable for the task. But a single turn will give you some usable EMI suppression at 2MHz only in an extremely low impedance circuit. For most applications instead you will have to wind several turns. Between 10 and 30 turns would be typical for that frequency.
You also need to be aware of how much current is flowing through that wire where you need EMI suppression. If the current is negligible, than that's fine. But if it's significant, you need to calculate how many turns you can wind without saturating the core. A saturated core won't suppress much EMI. If you have significant current in that wire, you need to re-evaluate your three materials at the intended operating current, because a ferrite with lower permeability, such as your #2 and #3, can take more ampereturns without saturating, so they might end up being better than #1 in certain situations.
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Re: Comparison Testing of Three Ferrite Beads using the Smith Chart
Kent,
your grandad, according to your qrz.com bio, was an interesting chap. Terman has next to nothing to say about toroidal inductors. A modern ARRL (or RSGB) handbook has rather more familiarity, though only the ARRL offers the n^2 formula for inductance. So 10 turns would give values much closer to 50¦¸ for more reliable measurements.
You may also find it useful to sweep over a two decade range, say from 100kHz to 20MHz. And for EMC suppression, lossy is often better, depending on the specific detail of what one is trying to do.
HTH, 73, Stay Safe,
Robin, G8DQX
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On 12/04/2021 00:40, Kent AA6P wrote: I have three different ferrite beads of the same size and would like to know which one would provide the greatest EMI Suppression at 2.0 MHz. The ferrite beads have a diameter of 0.5" and a height of 0.25".
Here is a description of the test I ran yesterday. I'd appreciate any interpretation of the results.
My NanoVNA was calibrated at 2.0 MHz for testing on Channel 0. I attached a 50 ohm carbon resistor with two one inch leads to the Channel 0 connector and measurements were recorded. Ferrite beads were then inserted over the resistor one at a time after temporarily disconnecting one lead.
50 Ohm Resistor: SWR 1.02, Smith Chart 48.9 ohms 29.3 nH
Ferrite Bead 1: SWR 1.11, Smith Chart 49.6 ohms 429 nH
Ferrite Bead 2: SWR 1.08, Smith Chart 49.2 ohms 293 nH
Ferrite Bead 3: SWR 1.02, Smith Chart 49.0 ohms 54.4 nH
A second test was run using a two inch piece of wire instead of the resistor.
Two Inch Wire: Smith Chart 117 milliohms 93.8 nH
Ferrite Bead 1: Smith Chart 759 milliohms 495 nH
Ferrite Bead 2: Smith Chart 320 milliohms 361 nH
Ferrite Bead 3: Smith Chart 208 milliohms 125 nH
Any observations or comments would be appreciated.
I also have a question on the Smith Chart which traditionally has had a Resistance Axis and a Reactance Axis. Is the NanoVNA simply translating the reactance at the marker frequency to the associated capacitance or inductance?
Thanks, Kent
AA6P
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Re: Comparison Testing of Three Ferrite Beads using the Smith Chart
Well, common sense would suggest that the greatest increase of impedance is ferrite bead one.
I would have thought that winding, say, six turns through each one would give larger inductance values to compare.
Steve L
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My H4 was made 02/20 0.5.0 firmware.? loosened screws, but no difference.? Tried all the touch screen test etc.
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On Sunday, April 11, 2021, 3:36:08 AM EDT, Gyula Molnar <gyula.ha3hz@...> wrote:
Hi Joe,
You may have bought from the first production.
These were characterized by this error that the front panel was pressed against the touch screen and the touch screen did not work.
Follow the description in front of me and you can use it.
Don¡¯t worry, we¡¯ve discussed a lot of options here in the forum.
If you have any setup, measurement or any problems, here is the forum.
Use the forum 'Search' button to enter the appropriate text and you will get a lot of results for help.
Also, check out the forum's 'Wiki' and 'Files' folders.
73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***
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Re: Identifying ferrite mix material?
On Sat, Apr 10, 2021 at 09:44 PM, Maynard Wright, P. E., W6PAP wrote: To be clear, I am using older versions of these tools, but I suspect that more
recent versions will behave in the same manner. Most recent version of Octave (6.2.0) gives the same answers: atanh(1)
ans = Inf tanh(atanh(1))
ans = 1 I just started playing with Octave recently. What a wonderful tool!
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Comparison Testing of Three Ferrite Beads using the Smith Chart
I have three different ferrite beads of the same size and would like to know which one would provide the greatest EMI Suppression at 2.0 MHz. The ferrite beads have a diameter of 0.5" and a height of 0.25".
Here is a description of the test I ran yesterday. I'd appreciate any interpretation of the results.
My NanoVNA was calibrated at 2.0 MHz for testing on Channel 0. I attached a 50 ohm carbon resistor with two one inch leads to the Channel 0 connector and measurements were recorded. Ferrite beads were then inserted over the resistor one at a time after temporarily disconnecting one lead.
50 Ohm Resistor: SWR 1.02, Smith Chart 48.9 ohms 29.3 nH
Ferrite Bead 1: SWR 1.11, Smith Chart 49.6 ohms 429 nH
Ferrite Bead 2: SWR 1.08, Smith Chart 49.2 ohms 293 nH
Ferrite Bead 3: SWR 1.02, Smith Chart 49.0 ohms 54.4 nH
A second test was run using a two inch piece of wire instead of the resistor.
Two Inch Wire: Smith Chart 117 milliohms 93.8 nH
Ferrite Bead 1: Smith Chart 759 milliohms 495 nH
Ferrite Bead 2: Smith Chart 320 milliohms 361 nH
Ferrite Bead 3: Smith Chart 208 milliohms 125 nH
Any observations or comments would be appreciated.
I also have a question on the Smith Chart which traditionally has had a Resistance Axis and a Reactance Axis. Is the NanoVNA simply translating the reactance at the marker frequency to the associated capacitance or inductance?
Thanks, Kent
AA6P
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Re: Identifying ferrite mix material?
The old Siemens B62152 ferrite core series were colour coded with a fuzzy spray of paint across one edge. For example I recall that the A1 X1 twin hole beads were faintly flashed with purple paint. I think another version with a lower permeability was flashed with pale grey. This made it easy to tell them apart at a glance.
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Re: Identifying ferrite mix material?
Agreed have had the same thought.I have often wondered what happens when outside people are hired for stocktaking.These are black round with a hole in them ,must be the same.Stick them in the one box.
73 Morrie
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On 12/04/2021 6:11 am, Chris K2STP wrote: I¡¯ve often wondered WHY there is no standard for MARKING ferrite¡¯s, so it¡¯s not a guessing game????
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I meant the conversion of the original design to KICAD.
I presumed that, that was the first step.
In any case looking forward to seeing your improvements,
V2 is a good OSH project and deserves to be improved.
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On Sun, 11 Apr 2021 at 17:06, <593799546myl@...> wrote: The current design has not been successfully debugged, so it cannot be
uploaded to github temporarily.
I am about to revise a version and see the new idea of reflection bridge
suggested by OWO, so I plan to revise the design of reflection bridge
together.
After the debugging is completed, I will upload it to github.
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Re: Identifying ferrite mix material?
I¡¯ve often wondered WHY there is no standard for MARKING ferrite¡¯s, so it¡¯s not a guessing game????
--
Regards,
Chris K2STP
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Nano VNA F PC interface trouble (probably caused by operator error)
My Nano VNA came from Sysjoint. Is my gadget compatible with the VNA software such as Saver and One of 11 ?
My gadget works quite well off-line.
When I connect the gadget on my Windows 10 PC, none of the above software downloaded from this website will connect to my gadget. The space for the COM3 is blank and the "rescan" and "conect" buttons do nothing. My system has an "STM Virtual Com Port" driver from Microsoft. If this is not right, where is the link to the correct driver ?
My firmware is version 0.2.0. I hold the center toggle button while powering on and copy the update.bin file to my gadget, however the next normal power on shows the firmware version unchanged. What am I doing wrong ?
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The current design has not been successfully debugged, so it cannot be uploaded to github temporarily.
I am about to revise a version and see the new idea of reflection bridge suggested by OWO, so I plan to revise the design of reflection bridge together.
After the debugging is completed, I will upload it to github.
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Gyula Molnar
Charlie Bess
Jim Allyn - N7JA
Chris K2STP