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Manfred, Have you ever compared the Q readings measured by the old BRC-160 or the Hp 4342 Q meters against the Q reported by any network analyzer or even many of the older 4 terminal instruments from the 70's and 80's and maybe into the 90's? The old Q meter uses a parallel resonant circuit technique and this was considered the best method until technology caught up. I had to work with inductor suppliers using "modern" instruments to measure Q when we were using the tuned-circuit method. Big difference in the reported Q. Then things started to agree as the 4 terminal methods improved. Yes, the resistance is so low compared to the reactance that is is difficult to get an accurate or true Q.

Ariel, From your picture it is difficult to tell if the high Z secondary windings are connected together for a back-back config and what are the number of turns on the primary and secondary's?

Hi Larry,
Yes, I have the H4 version. I also tried V1.0.38 and V1.0.26 but no change. For some reason with all these version mu unit will not scan. I wonder if there is some setting I can change via terminal to fix it, but I don't know where to look. We need a software expert.
73, John, K9KA

Hi,
Roger have shown two plots with increase of capacitance with frequency, as the leads become longer the capacitance seems grows. It is caused by inductance but as I understand the model of real capacitor, the series capacitance extracted from it should not change. Should it be a influence of series inductance on measurement accuracy? I mean with the frequency increase the inductance impedance becomes much larger than the capacitance so we are getting bigger ratio between of them destroying the capacitance measurement?

--
Regards,

Slawek/SP9BSL

On 3/17/21 8:50 PM, Barclay J. Tullis wrote:

Eureka!!
Larry and Jim: Thank you for your generosity in giving me some good information and guidance which will benefit me in future endeavors. My good news is that by moving the dfu file to my desktop in Windows 7 and shortening the file name, the firmware upgrade went smoothly and successfully without any so-called format issues. I have to give credit to Harry Morton N4HBM who in an earlier response in the archives to a similar question suggested this solution. Admittedly, I did have a long path in my files structure to reach the dfu file. Thanks to all of you good folks.
Barclay W6WT

filename lengths are a common problem.? For instance some programs only have 64 or 32 characters for the filename (because they assume the files are in the directory that it's being run in, and who in their right mind would use more than an 8.3 filename)

Eureka!!
Larry and Jim: Thank you for your generosity in giving me some good information and guidance which will benefit me in future endeavors. My good news is that by moving the dfu file to my desktop in Windows 7 and shortening the file name, the firmware upgrade went smoothly and successfully without any so-called format issues. I have to give credit to Harry Morton N4HBM who in an earlier response in the archives to a similar question suggested this solution. Admittedly, I did have a long path in my files structure to reach the dfu file. Thanks to all of you good folks.
Barclay W6WT

I probably need to clarify the plot - x axis is a sweep from 3-30 MHz. Y axis is s21 after I divided by 2 cores - loss per core.

Ariel NY4G

Hmmm, I thought there was a section in the wiki on using a Mac to flash the firmware. Have a look at my edited user guide in the files section.?
Look at chapter 8.?/g/nanovna-users/files/NanoVNA-User-Guide-English-reformat-Jan-15-20.pdf
As for the format of the firmware files, there is nothing wrong with them. Many members have had no issues.? ?If you need to convert them to .bin files, use the defuse file manager utility that is installed along with defuse.?
Also search the messages for the terms mac and firmware.?


On Wed., 17 Mar. 2021 at 8:58 p.m., Barclay J. Tullis<barc@...> wrote: Thank you Larry for the suggestions.? I couldn't find anything useful in either Wiki or Files for this issue of "not a correct format".? In the archives, I see that Harry Morton N4HBM suggested that shortening the firmware file-name worked for him, but it's not working for me.? Also, I can't find any useful information on using DfuSe on a Mac, not even from STMicroelectronics.
Barclay

What am I doing wrong? The chart I plotted from the nanoVNA into Excel just does not look right. This is the back to back method. Two cores, secondaries together, grounds together, and measure loss between ports 1 and port 2 (S21) - photo also attached. My calibration looks OK.

Thanks

Ariel NY4G



?On 3/17/21, 3:58 PM, "[email protected] on behalf of jmr via groups.io" <[email protected] on behalf of jmrhzu@...> wrote:

Hi WB2AUQ, that all sounds good now.

I had another play with the s2p file of the (big) stacked FT240 49:1 transformer. This includes the 110pF capacitor at the input. I put the s2p model of the transformer and the input cap back to back and did an insertion loss comparison. I added a x2 factor to the trace for the back to back measurement and the plot is shown below. This shows that in this case the back to back method would be OK across most of the band as the traces agree very closely. However, it is a risky method especially if the network has a lot of reactance across the passband. You can see that this is what happens at the band edges where the traces diverge quite a bit.

Note that this s2p file was not taken with a nanovna. It was taken some time ago using an Agilent VNA and a full 2 port cal using an Aglent N4431-60006B Ecal. It also uses the 'fixture simulator' feature in the Agilent analyser that has a very accurate s2p model of my 2 port text fixture. This corrected fixture system works very well up to many GHz and it can accurately shift the reference plane right to the pins of the device under test so I think the results below can be trusted with high confidence.

On 3/17/21 5:58 PM, Barclay J. Tullis wrote:

Thank you Larry for the suggestions. I couldn't find anything useful in either Wiki or Files for this issue of "not a correct format". In the archives, I see that Harry Morton N4HBM suggested that shortening the firmware file-name worked for him, but it's not working for me. Also, I can't find any useful information on using DfuSe on a Mac, not even from STMicroelectronics.
Barclay

I think you need dfu-util - HomeBrew and MacPorts do it.

(base):~ jimlux$ brew install dfu-util

100 lines of stuff..

(base) :~ jimlux$ dfu-util
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to

You need to specify one of -D or -U
Usage: dfu-util [options] ...
? -h --help??? ??? ??? Print this help message
? -V --version??? ??? ??? Print the version number
? -v --verbose??? ??? ??? Print verbose debug statements
? -l --list??? ??? ??? List currently attached DFU capable devices
? -e --detach??? ??? ??? Detach currently attached DFU capable devices
? -E --detach-delay seconds??? Time to wait before reopening a device after detach
? -d --device <vendor>:<product>[,<vendor_dfu>:<product_dfu>]
??? ??? ??? ??? Specify Vendor/Product ID(s) of DFU device
? -p --path <bus-port. ... .port>??? Specify path to DFU device
? -c --cfg <config_nr>??? ??? Specify the Configuration of DFU device
? -i --intf <intf_nr>??? ??? Specify the DFU Interface number
? -S --serial <serial_string>[,<serial_string_dfu>]
??? ??? ??? ??? Specify Serial String of DFU device
? -a --alt <alt>??? ??? Specify the Altsetting of the DFU Interface
??? ??? ??? ??? by name or by number
? -t --transfer-size <size>??? Specify the number of bytes per USB Transfer
? -U --upload <file>??? ??? Read firmware from device into <file>
? -Z --upload-size <bytes>??? Specify the expected upload size in bytes
? -D --download <file>??? ??? Write firmware from <file> into device
? -R --reset??? ??? ??? Issue USB Reset signalling once we're finished
? -s --dfuse-address <address>??? ST DfuSe mode, specify target address for
??? ??? ??? ??? raw file download or upload. Not applicable for
??? ??? ??? ??? DfuSe file (.dfu) downloads
(base):~ jimlux$

Thank you Larry for the suggestions. I couldn't find anything useful in either Wiki or Files for this issue of "not a correct format". In the archives, I see that Harry Morton N4HBM suggested that shortening the firmware file-name worked for him, but it's not working for me. Also, I can't find any useful information on using DfuSe on a Mac, not even from STMicroelectronics.
Barclay

Windows emulation on a Mac is not 100%. You will be better off using the Mac natively to push new FW to the Nano.?
Search the forum wiki, user messages and a few of the user guides for Mac specific flashing instructions.?


On Wed., 17 Mar. 2021 at 4:24 p.m., Barclay J. Tullis<barc@...> wrote: How do I solve this?? I get an error message "This file doesn't have a
correct format ." when I try to upgrade my NanoVNA-H.?

Background and details:? This happens in the STMicroelectronic's DfuSe
v3.0.6 software interface when I try to upgrade my NanoVNA-H
v0.2.3-2-g8ac9166 using either Dislord's Nanovna -H Firmware files
"NanoVNA-H v1.0.39.dfu" or "NanoVNA-H v1.0.45.dfu" which I extracted from
the zipped files "NanoVNA v1.0.39.rar" and "NanoVNA v1.0.45.rar".? I have
tried both Windows 7 on a PC (64-bit OS) and Windows 10 (64-bit OS) within
Parallels on a MacBook Pro (Intel processor).? And I have installed drivers
for DfuSe by running dpinst_amd64.exe from the STMicroelectronics driver
folder under Program Files (X86).? In Device Manager under Ports and opening
Properties->Driver Details, the name and location of the driver is given as
C:\windows\system32\DRIVERS\usbser.sys with version 6.1.7601.18247 in
Windows 7 and 10.0.18362.1 in Windows 10.? And I rebooted after installing
those drivers.? I'm puzzled why the drivers have the name usbser rather than
STTub32, although the DfuSe Demo does report "STM Device in DFU mode" is
available.



My first post.? Reading the Wiki info on troubleshooting firmware and driver
issues didn't yield an answer, nor did searching other's posts.

How do I solve this? I get an error message "This file doesn't have a
correct format ." when I try to upgrade my NanoVNA-H.

Background and details: This happens in the STMicroelectronic's DfuSe
v3.0.6 software interface when I try to upgrade my NanoVNA-H
v0.2.3-2-g8ac9166 using either Dislord's Nanovna -H Firmware files
"NanoVNA-H v1.0.39.dfu" or "NanoVNA-H v1.0.45.dfu" which I extracted from
the zipped files "NanoVNA v1.0.39.rar" and "NanoVNA v1.0.45.rar". I have
tried both Windows 7 on a PC (64-bit OS) and Windows 10 (64-bit OS) within
Parallels on a MacBook Pro (Intel processor). And I have installed drivers
for DfuSe by running dpinst_amd64.exe from the STMicroelectronics driver
folder under Program Files (X86). In Device Manager under Ports and opening
Properties->Driver Details, the name and location of the driver is given as
C:\windows\system32\DRIVERS\usbser.sys with version 6.1.7601.18247 in
Windows 7 and 10.0.18362.1 in Windows 10. And I rebooted after installing
those drivers. I'm puzzled why the drivers have the name usbser rather than
STTub32, although the DfuSe Demo does report "STM Device in DFU mode" is
available.



My first post. Reading the Wiki info on troubleshooting firmware and driver
issues didn't yield an answer, nor did searching other's posts.

On Wed, Mar 17, 2021 at 12:49 AM, Roger Need wrote:

I too have had good luck measuring low and high impedances on my NanoVNA-H4
using the S11 method. I got about 1% accuracy measuring a 1K SMD resistor
and 3.5% (worst case) with a 3K SMD with a good test jig using accurate cal
loads up to 300 MHz. I posted about it in the "Pitfalls" thread a few weeks
ago in this group. High reactance components (caps, inductors, chokes) can
also be measured this way. .

/g/nanovna-users/message/20941

Roger

Thanks. There's some interesting and useful info in your link. I think that good information soon gets buried on forums like this which is a shame.
Also, I wasn't aware of the alternative software options for the nanovna. I abandoned the nanosaver SW a long time ago and wrote my own (very basic) tools to dump out s1p and (DUT reverse supported) s2p files as I just couldn't get on with the user interface for nanosaver.

Hi WB2AUQ, that all sounds good now.

I had another play with the s2p file of the (big) stacked FT240 49:1 transformer. This includes the 110pF capacitor at the input. I put the s2p model of the transformer and the input cap back to back and did an insertion loss comparison. I added a x2 factor to the trace for the back to back measurement and the plot is shown below. This shows that in this case the back to back method would be OK across most of the band as the traces agree very closely. However, it is a risky method especially if the network has a lot of reactance across the passband. You can see that this is what happens at the band edges where the traces diverge quite a bit.

Note that this s2p file was not taken with a nanovna. It was taken some time ago using an Agilent VNA and a full 2 port cal using an Aglent N4431-60006B Ecal. It also uses the 'fixture simulator' feature in the Agilent analyser that has a very accurate s2p model of my 2 port text fixture. This corrected fixture system works very well up to many GHz and it can accurately shift the reference plane right to the pins of the device under test so I think the results below can be trusted with high confidence.

Now feel pretty stupid! I did the usual OSL cal and now I see much higher Z's with the port left open.
Thinking back now, I was using Nanovna Sharp until about a year or so ago. I installed "Saver" at some time and even upgraded it once. Maybe "Sharp" was not applying the cal data correctly? Have no idea. I don't recall looking at the Smith Chart with the port left open for a long time now. All of the low impedance measurements and matching I have done all seemed to work out just fine.

Hi DiSlord,

maybe ISOLN is not necessary anymore on V2-VNAs. But I didn't read about it.
And isn't something wrong, if at the left side of display there are only two letters: C* and D ?
Thanks for help!

tom

Hi Larry,

it's a NanoVNA V2_2
Hardware designed by 0w0Comm
Version git-20200617-1a9a11d
Build Time: Jun 19 2020
Kernel: None (?!?)
Compiler: gcc
Architecture arm Core Variant: N/A
Port Info: GD32F303
Board: NanoVNA V2_2
Has FPU: yes

- Yes, I did a reset befor calibrating
- I am worried about the letters at the left side of the screen: It's only "C*" and "D"

I was not able to update the firmware, but will keep trying...

Thanks for help!

tom

I too have had good luck measuring low and high impedances on my NanoVNA-H4
using the S11 method. I got about 1% accuracy measuring a 1K SMD resistor
and 3.5% (worst case) with a 3K SMD with a good test jig using accurate cal
loads up to 300 MHz. I posted about it in the "Pitfalls" thread a few weeks
ago in this group. High reactance components (caps, inductors, chokes) can
also be measured this way. .

My mileage varies. What seems particularly difficult is measuring an impedance consisting of a small resistance a large reactance, or the other way around. This is crucial, for example, to directly measure the Q or the loss factor of inductors and capacitors. When the actual Q is more than 100 or so, I haven't been able to get any reasonable estimation at all from the NanoVNA. Mica and polypropylene capacitors should have a Q factor of several thousand. I'm attaching the Q curve I got for a 2000pF silver mica capacitor, after careful calibration. It's nonsense.

Measuring again, only in the range to 1MHz, where the reactance of this capacitor isn't as low as at higher frequencies, and using averaging, I got the second curve attached. It too is unusable, being wrong by more than an order of magnitude at its best point.

In such a situation it's required that the NanoVNA very accurately measures the phase angle of the reflection, which is strong but extremely close to 90°. A tiny difference in the measured phase angle means a huge difference in the Q. There are always limits in terms of phase noise, ADC resolution, and others, and this puts certain measurements out of the reach of an instrument.

A resistor of several kiloohm measures very precisely on my NanoVNA. But measurements that are highly sensitive to phase don't work well enough to be usable.

Dumb question - you flashed the H4 firmware and not the H, right?

There are binaries for both devices in the 1.0.45 archive.