The SMA jack cal kit and test connector shown by Roger is going to be much better than the other jigs IMO. If anyone does want to make one I'd recommend trying to buy the connectors as branded parts from a decent supplier. I'd avoid searching for the cheapest ones from the far east via ebay. There might not be much advantage in performance but these connectors will be used a lot possibly for a few years so I'd recommend getting something with accurate machining and decent materials so it doesn't cause premature wear in other SMA cables or adaptors.
I've got various SMA based cal kits here and my earliest one that I still use for casual stuff is over 15 years old. I'd favour buying the chunkier end launch ones made by Suhner or Johnson but these are a bit more expensive. They are much nicer to use for dev work and I buy them regularly. Usually 25 at a time for a decent discount.
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On Tue, Sep 7, 2021 at 10:14 AM, Donald S Brant Jr wrote:
I have made such standards in the past and have found that using 3 x 150¦¸ or
4 x 200¦¸ resistors makes a significantly-better load that a single 49.9¦¸
one, likely due to paralleling the resistors' inductances.
73, Don N2VGU. Yes using more than one resistor for the load gives better results. I got the idea for doing this from an article posted online. He shows performance with SMA male and female parts. Roger
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Albert, Looking at the jigs, I don't understand the benefit of using Manfred's, since
it has large areas of plane on both conductors. Doesn't that introduce more
parasitic capacitance than Roger's small jumper pin fixture?
The benefit is simply that one can easily and quickly clamp components of vastly different sizes to it. And the downside is that measurement accuracy is worsened by the uncertainty of where exactly on the planes each component terminal makes contact. So I would not use this jig to measure the stray inductance of an SMD resistor, for example. The result might be too imprecise. A jig like Roger's is better for that task, as it gives far better reproducibility of the parasitic reactances and resistances. But while Roger is still soldering his parts to his connectors, I have already finished the measuremnts! That's the advantage of mine: Speed and convenience. If you want the best flexibility, simply build both! They are easy and cheap enough to make. Don't worry about the capacitance between the two contact areas of my jig. It's single-sided board, so the capacitance is probably less than 1pF, and the NanoVNA's calibration totally takes care of it. And the large planes help in reducing the series inductance, which is what varies most when clamping a component to different spots of the planes. I'm using my jig a lot, and haven't seen a need to build another so far. But of course I'm very aware that it has its limitations. Mainly an uncertainty of about 2nH due to different contact spots of the shorting strap and the component under test. And when just clamping the parts to the jig, there is also a variable resistance there, so for critical ESR measurements it's better to solder down the parts (and alos the calibrators, of course). Note that my jig gives the choice between clamping and soldering, at all times! Hmm, I'm getting good at advertising! ;-)
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I have made such standards in the past and have found that using 3 x 150¦¸ or 4 x 200¦¸ resistors makes a significantly-better load that a single 49.9¦¸ one, likely due to paralleling the resistors' inductances.
Extending the outer conductor on the open standard with a piece of brass tubing also improves its performance by minimizing its radiation; the tube is essentially a waveguide below cutoff. This is only apparent at X-band and above.
73, Don N2VGU.
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This is a reply to all of the respondents:
I learn all the time from from posts like these. The interactions of these most learned of people always amaze me and is reminiscent of the nearly 40 years I spent in aerospace where sages of all disciplines would combine to create solutions that might seem impossible were it not that they really work.
One of my problems is that I know enough to be dangerous to myself and others and I learn this on a daily basis. I say all this because this topic is a perfect example in which I want to learn but my limited knowledge of certain electro-physical phenomena comes to an end. Various references (i.e., classic texts) to these phenomena are practically (physically/financially) out-of-reach, so, I carefully tease knowledge from what people like Roger, Don, Manfred, et al., spill out onto to these posts.
For example, "I think" I intuitively (or entertain the illusion that) understand the reason that the planes of Manfred's circuit board jig have little parasitic effect at certain (most) frequencies but I would not be able to supply the proof. (That was always my problem in advanced topics in calculus.)
A common problem is sometimes I get lost in "lingo" or what to you all is common terminology and need to resort to the vast "knowledge" of the internet. (Uggh!)
Anyway, I'm whining and the real purpose of my post is to thank you all for sharing your knowledge as I have seldom seen anything so practical in academic circles and you all expound on topics of a clearly useful purpose which supplies me with many "Aha!" moments.
So, thanks again, as this has been a highly useful and informative topic for me and has likely explained some problems I've had measuring components.
Will
W6SWF
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This is another method I use to test components when I am interested in higher frequencies and/or improved accuracy. It gives a better reference plane than the SMA pin jack method and is also useful when you want to establish the reference plane at the end of a SMA cable for other types of measurements.
Four SMA PCB mount jacks are required. The legs and and the centre pin are removed on three of them to make open short and cal loads. On the open you cut the centre pin flush with the dielectric and then use a dremmel tool to remove a bit more - this reduces fringing capacitance. For the short you take a piece of copper foil slightly smaller than the bottom surface area of the jack. Push it over the centre pin and then solder the entire bottom area to the metal surface of the jack. Then clip off the excess center pin. For the load I used a 49.9 ohm 0805 SMD resistor that I had in the parts bin. I used my DE-5000 LCR meter with Kelvin clips to handpick one that was as close to 50 ohms as possible. Two 100 ohm SMD resistors would be slightly better if you have them available.
The fourth jack is used for the component under test. It can be a leaded component or an SMD part. I remove all the legs but one. Shorten the remaining leg and the center pin to reduce inductance and then tack solder the component to the centre pin and leg. Connect it to the cable and make your measurement.
Roger
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In my case I had to actually go to the mentioned folder and install the "STM device in DFU mode" as it did not appear as one of the choices of available drivers.
Hope it works for you...let us know. Apparently this problem is not uncommon as the correct driver installs automatically for some but not others.
Thanks again to Don KB5QR who's post helped me out.
73, Dave - W3NP
toggle quoted message
Show quoted text
On 9/7/2021 12:00 PM, Andy-kf7vol wrote: That's what I needed. I will give that a try when I get home tonight.
Thanks, Dave!
On Tue, Sep 7, 2021 at 8:57 AM Dave W3NP <w3np@...> wrote:
I had the same or similar problem last week when upgrading my H4. It
was a driver problem. Windows kept loading the STM32 Bootloader driver
and I needed the "STM device in DFU mode" driver ......I found this post
by Don KB5QR and it got me on the right road:
/"I ran into the same problem with Windows 10 not seeing my NanoVNA in
DFU mode. I found the fix via a Google search that led me to forum on
www.deviationtx.com. One of the members by the handle of "Nuggetz"
suggested that the driver in use was not the DFU version. This is what
he did, and it worked for me:
Connect the NanoVNA and put it in DFU mode. Go into device manager and
find the STM device under "Universal Serial Bus devices" (at the very
bottom of the window). Expand this item and you will probably see "Hub
Controller" and "STM32 BOOTLOADER". Right Click on "STM32 BOOTLOADER"
and select update driver then choose "Browse my computer for drivers".
After that, select "Let me pick from a list of available drivers on my
computer".
The driver choices you see there should include "STM device in DFU
mode". Select the DFU mode one and that'll do it.
If you don't see both "STM32 BOOTLOADER" and "STM device in DFU mode",
/_*then you probably need to install the driver using the
dpinst_amd64.exe utility, found in the Win10 folder under Program
Files(x86)/STMicroelectronics/Software/DfuSe v3.0.6/Bin/Driver.*_/
/ /
Hope this Helps.
73,
/
/Don, KB5QR"/
/
/
I was able to complete the upgrade without any further issues. Thanks
Don!!!
73, Dave - W3NP
On 9/7/2021 11:16 AM, Andy-kf7vol wrote:
Good Morning,
I didn't make any driver change after having a success story updating my H model. When I plug in the H4 and hold the button down and power on to DFU
mode it still is not recognized.
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On Tue, Sep 7, 2021 at 06:54 AM, Donald S Brant Jr wrote:
The leads on the SMD plugins could be cut down to where the diameter gets
bigger and the leads on the SMA jack and the socket could be cut back as well.
This would decrease the inductance of the fixture and improve performance at
higher frequencies and smaller-value components.
73, Don N2VGU.
That is a good suggestion. There is always room for improvement. Roger
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That's what I needed. I will give that a try when I get home tonight.
Thanks, Dave!
toggle quoted message
Show quoted text
On Tue, Sep 7, 2021 at 8:57 AM Dave W3NP <w3np@...> wrote: I had the same or similar problem last week when upgrading my H4. It
was a driver problem. Windows kept loading the STM32 Bootloader driver
and I needed the "STM device in DFU mode" driver ......I found this post
by Don KB5QR and it got me on the right road:
/"I ran into the same problem with Windows 10 not seeing my NanoVNA in
DFU mode. I found the fix via a Google search that led me to forum on
www.deviationtx.com. One of the members by the handle of "Nuggetz"
suggested that the driver in use was not the DFU version. This is what
he did, and it worked for me:
Connect the NanoVNA and put it in DFU mode. Go into device manager and
find the STM device under "Universal Serial Bus devices" (at the very
bottom of the window). Expand this item and you will probably see "Hub
Controller" and "STM32 BOOTLOADER". Right Click on "STM32 BOOTLOADER"
and select update driver then choose "Browse my computer for drivers".
After that, select "Let me pick from a list of available drivers on my
computer".
The driver choices you see there should include "STM device in DFU
mode". Select the DFU mode one and that'll do it.
If you don't see both "STM32 BOOTLOADER" and "STM device in DFU mode",
/_*then you probably need to install the driver using the
dpinst_amd64.exe utility, found in the Win10 folder under Program
Files(x86)/STMicroelectronics/Software/DfuSe v3.0.6/Bin/Driver.*_/
/ /
Hope this Helps.
73,
/
/Don, KB5QR"/
/
/
I was able to complete the upgrade without any further issues. Thanks
Don!!!
73, Dave - W3NP
On 9/7/2021 11:16 AM, Andy-kf7vol wrote:
Good Morning,
I didn't make any driver change after having a success story updating my H model. When I plug in the H4 and hold the button down and power on to DFU
mode it still is not recognized.
--
*Andy Sayler, Head Monkey | Keyed Up/Oil Can Garage.*
Down The Street | Lynden, WA 98264 | mobile (360) 319-7417
|
I had the same or similar problem last week when upgrading my H4.? It was a driver problem. Windows kept loading the STM32 Bootloader driver and I needed the "STM device in DFU mode" driver ......I found this post by Don KB5QR and it got me on the right road:
/"I ran into the same problem with Windows 10 not seeing my NanoVNA in DFU mode. I found the fix via a Google search that led me to forum on www.deviationtx.com. One of the members by the handle of "Nuggetz" suggested that the driver in use was not the DFU version. This is what he did, and it worked for me:
Connect the NanoVNA and put it in DFU mode. Go into device manager and find the STM device under "Universal Serial Bus devices" (at the very bottom of the window). Expand this item and you will probably see "Hub Controller" and "STM32 BOOTLOADER". Right Click on "STM32 BOOTLOADER" and select update driver then choose "Browse my computer for drivers". After that, select "Let me pick from a list of available drivers on my computer".
The driver choices you see there should include "STM device in DFU mode". Select the DFU mode one and that'll do it.
If you don't see both "STM32 BOOTLOADER" and "STM device in DFU mode", /_*then you probably need to install the driver using the dpinst_amd64.exe utility, found in the Win10 folder under Program Files(x86)/STMicroelectronics/Software/DfuSe v3.0.6/Bin/Driver.*_/
/ /
Hope this Helps.
73,
/
/Don, KB5QR"/
/
/
I was able to complete the upgrade without any further issues. ?? Thanks Don!!!
73, Dave - W3NP
toggle quoted message
Show quoted text
On 9/7/2021 11:16 AM, Andy-kf7vol wrote: Good Morning,
I didn't make any driver change after having a success story updating my H model. When I plug in the H4 and hold the button down and power on to DFU mode it still is not recognized.
|
Correct. The snag is its not recognizing it or populating in the DFU tool.
toggle quoted message
Show quoted text
On Tue, Sep 7, 2021 at 8:38 AM Vladimir Lebedev <dl7pga@...> wrote: Hello Andy!
NanoVNA-H4 in DFU mode has BLACK screen, not milk white on NanoVNA-H.
Vladimir
--
*Andy Sayler, Head Monkey | Keyed Up/Oil Can Garage.*
Down The Street | Lynden, WA 98264 | mobile (360) 319-7417
|
Hello Andy!
NanoVNA-H4 in DFU mode has BLACK screen, not milk white on NanoVNA-H.
Vladimir
|
Good Morning,
I didn't make any driver change after having a success story updating my H model. When I plug in the H4 and hold the button down and power on to DFU mode it still is not recognized.
|
Re: 6ghz unit available? - calibration strategies
On 9/7/21 5:13 AM, Donald S Brant Jr wrote: I have one of the LibreVNA units and it is working satisfactorily for me, but the provided calibration standards and/or their definitions, provided by Kurt Poulsen, only work up to about 3.8GHz; the calibration "falls apart" above that.
I have ordered a set of calibration standards from Dr. David Kirkby at Kirkby Microwave and they should work better at the higher frequencies. A set of calibration standards from Keysight, Anritsu, Maury Microwave, Rohde & Schwarz and others should also be suitable if they are available. It is important that correct and accurate calibration kit standards definitions are available and are entered into the analyzer's calibration routine. If incorrect or inaccurate definitions are used even the best standards will give erroneous results.
73, Don N2VGU.
One thing that not all the software supports, but one can tinker a bit with scikit-rf and achieve, is that you can use fairly "bad" cal standards, as long as they're repeatable and if you measure the standards "somewhere else". Sure, a perfect open, short, load, and thru with known perfect impedances and physical offsets is sort of the "easiest" (and the one used by the NanoVNA "out of the box") But it's entirely possible to take a load, go measure it on a "really good VNA" (maybe at work, or a friend has one, or ...) and then use that measurement in the calibration process. Here's an example in python """ measured standards""" cableopen = rf.Network('cable1open.s1p') cableshort = rf.Network('cable1short.s1p') cableload = rf.Network('cable1load.s1p') plt.figure() cableopen.plot_s_db(logx=True) cableshort.plot_s_db(logx=True) cableload.plot_s_db(logx=True) plt.title('RG-8 25ft') plt.grid() """ what you want """ idealshort = rf.Network() idealshort.copy_from(cableopen) idealshort.name='Ideal short' idealshort.s = idealshort.s * 0 -1 idealload = rf.Network() idealload.copy_from(cableopen) idealload.name='Ideal load' idealload.s = idealshort.s * 0 idealopen = rf.Network() idealopen.copy_from(cableopen) idealopen.name='Ideal open' idealopen.s = idealopen.s * 0 +1 """ build cal sets from short open load """ ideals = [idealshort,idealopen,idealload] measuredcable = [cableshort,cableopen,cableload] calcable = rf.OnePort(ideals=ideals,measured=measuredcable) calcable.run() --- and then you can use that calibration set """ read in the raw measurements """ """ then calibrate """ plt.figure() dut = rf.Network('test6ant.s1p') dut.frequency.unit='mhz' dut.plot_s_db(logx=True) dut_cal = calcable.apply_cal(dut) dut_cal.frequency.unit = 'mhz' dut_cal.name=dut_cal.name + ' calibrated' dut_cal.plot_s_db() plt.grid(True) rf.plotting.shade_bands(justbands,cmap=bandcmap,alpha=0.1)
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The leads on the SMD plugins could be cut down to where the diameter gets bigger and the leads on the SMA jack and the socket could be cut back as well. This would decrease the inductance of the fixture and improve performance at higher frequencies and smaller-value components.
73, Don N2VGU.
|
On 9/6/21 3:44 PM, Lou W7HV via groups.io wrote: On Mon, Sep 6, 2021 at 04:23 PM, Donald S Brant Jr wrote:
I think that the lead lengths on Roger's fixture could be tightened up quite a
bit. 73, Don N2VGU.
Perhaps, but not at all consequentially at 60MHz and below, IMO. I agree, a lot of that will "calibrate out" if you calibrate "at the jig". The key would be keeping leads in the same position they were in when you calibrated.
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I have one of the LibreVNA units and it is working satisfactorily for me, but the provided calibration standards and/or their definitions, provided by Kurt Poulsen, only work up to about 3.8GHz; the calibration "falls apart" above that.
I have ordered a set of calibration standards from Dr. David Kirkby at Kirkby Microwave and they should work better at the higher frequencies. A set of calibration standards from Keysight, Anritsu, Maury Microwave, Rohde & Schwarz and others should also be suitable if they are available. It is important that correct and accurate calibration kit standards definitions are available and are entered into the analyzer's calibration routine. If incorrect or inaccurate definitions are used even the best standards will give erroneous results.
73, Don N2VGU.
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|
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Hello Andy!
Have You driver for NanoVNA installed?
Driver for H works with H4 too.
Please not use driver from Windows.
Vladimir
|
Oy. TNX.
From the home of
Prof. Emeritus Raymond (Reuven) Boxman
School of Electrical Engineering
Tel Aviv University
Cell: ???? +972 544 634 217
CEO Clear Wave Ltd.? ?????????????
Scientific Writing Courses: ???????
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Mike C. Sent: ????? 07 ?????? 2021 05:47 To: [email protected]Subject: Re: [nanovna-users] nanoVNA developers Just a heads-up Raymond. Your 2 websites: CEO Clear Wave Ltd. Scientific Writing Courses: are "out to lunch", i.e. 'non-functional', just saying. I do like your "perspective", thanks for your input. Mike C. Sand-mountain, Trenton, GA, living on "the brow". On 9/3/2021 4:57 AM, Ray wrote: A little perspective:
I bought my nanoVNA V2, and also a spectrum analyzer, on Ali Express, well before I even knew about this user group. I came across it while looking for something else, and it immediately caught my attention. I had used a full feature VNA and spectrum analyzer once (costing about $100,000 and $30,000, respectively, or so I was told), and said to myself: hey, this looks neat and would come in handy for various projects I'm working on. I chose the model and the store on Ali based on getting something that would cover the 2.45 GHz ISM band, at a price less than $70 (to avoid paying customs), and generally at minimum price.
Unfortunately, the hardware arrived with almost 0 documentation. The only thing sent was a menu map, which was more or less useless. I was given a link to website, which had some minimal instructions which could not be carried out for calibrating. Corresponding with the vendor was completely unsatisfactory -- I am sure they have no idea what they are selling. For them if they sell a VNA, a pair of sneakers, or sex toys -- its exactly the same thing -- what is the profit margin. (The 35-4400 MHz Spectrum Analyzer came with even less documentation, and I have not yet managed to get it to work).
I had never heard of OwO, Hugens, or any of the dedicated people who developed firmware or software, or help other people on this group, until I came across this group searching for some kind of manual. All power to all of you! And many thanks!
But everyone should be aware that there is a commercial jungle out there. My suspicion is that many more people buy a nanoVNA because they saw a commercial advertisement, e.g. on Amazon or Ali, rather than from reading this group's discourse. Thus appeals in this group to respect the developers' wishes will probably have little effect. My advice to all developers, of whatever, is to first decide what your motivation is. If it is to profit from your work, which is perfectly legitimate, then you should take all of the legal precautions necessary, e.g. patent protection, secrecy, etc. This can be quite costly - probably a minimum of $10,000 for each country over the lifetime of the patent, if you know enough to file yourself (otherwise twice or thrice this figure). And if you need to defend a patent against infringement, the costs can easily get to the M$ range. Know that Murphy's law applies here - if something can be copied, and if it is worthwhile to copy, then it will be copied.
Or, a developer can decide that his or her motivation is not monetary, but rather helping mankind, helping the profession or the hobby, or even obtaining or strengthening one's reputation in the technical community. Then you might tell all and share all, and feel some satisfaction that others are benefitting from your efforts. In my opinion, any middle ground between these two approaches is apt to be frustrating.
With regards and gratitude,
Ray 4X1RB
From the home of
Prof. Emeritus Raymond (Reuven) Boxman School of Electrical
Engineering Tel Aviv University
Cell: ???? +972 544 634 217
CEO Clear Wave Ltd.? ????????????? Scientific
Writing Courses: ???????
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
OwO
Sent: ????? 02 ?????? 2021 16:20
To: [email protected]
Subject: Re: [nanovna-users] SAA-2N V2.2 DISPLAY ISSUES
I asked?, not forced, people to not help vendors that are selling copies of my design against my will.
How hard is it to simply STOP producing and selling copies of my design? My request is as simple as it gets. Is it that important to Hugen to make a profit off of my work and screw the original developers over while doing it?
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Roger Need
Donald S Brant Jr
2sheds
Vladimir Lebedev