VNA Help for microwave analyzers
I use this SW for many tasks and interface via the HPIB bus to load calibration tables for my VNA(s).
There are tips and application notes and excellent information at this site.
The SW is free down load.
An arrangement of this type SW with the NanoVNA added would be a significant assist. Up loading via USB.
My search on this site shows no prior mention of this tool, so find it added below:
Alan
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I've been happily using the NanoVNA and various versions of "Saver" for a lot of projects lately, but some were just motivated by curiosity about the device.
Unfortunately I have no other analyzer to compare to. In any case here are some sweeps from earlier tests that might be useful for reference or amusement. In most cases, they were done with my very early attempts at full bandwidth calibration.
- The fm filter is a commercial product from the rtl-sdr.com people.
- The LW filter is a homebrewed design I use to augment VLF beacon hunting.
- The multiband dipole is my 20ft high 80/40 meter trap dipole that has been augmented with parallel dipoles for 15 and 10. The feedline has a toroid common mode filer.
- The 6 meter antenna is an attic mounted dipole with a toroid common mode filter.
I've also used happily used the device and "saver" to design and build a 6 meter "squalo", but forgot to save the files from the latest testing run. I'm currently working on a 400-700 mhz indor LPA design and plan to try to use the device for relative pattern and gain testing.
Earlier tests with several types of 500-900mhz 1/4 wave mag-mount antennas and TV rabbit ears showed useful relative gain results at 2-3 wavelength spacings.
73, AE0GL
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Re: Further Comments on Resistive Bridges
Ideal resistive bridge response:
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Re: Advice sought on specific measurement.
Hans,
The tdr function, available standalone in the recent firmware upgrades and connected to a pc via software program, is good for evaluating cables. It can give you info about discontinuities, cable length and impedance bumps. I measured a 25 ft length of RG58 cable using the tdr option of Rune's nanoVNA Saver program and it found a short at 5 ft from the end of one of the connectors. Saved me the grief of installing a defective cable in my ham shack.
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Re: Does anyone know how sensitive the nanovna is to electrostatic discharge?
On Sun, Sep 22, 2019 at 03:15 AM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:
On Sun, 22 Sep 2019 at 08:10, Dr. David Kirkby <
drkirkby@...> wrote:
I fail to see the need to worry if the active devices is connected across
a 50 ohm resistor. 50 ohms is effectively a short circuit as far as static
is concerned.
Here¡¯s a video from dave Jones of EEVBLOG measuring the DC resistance of
antistatic mats.
Two DVM probes are put next to each other, the meter, which can read upto
300 M ohm can measure anything.
I should have said that the meter can not measure the resistance - it is
over 300 M ohm.
You are not going to zap the NanoVNA with static on its RF input terminals.
--
Dr. David Kirkby,
David, antistatic mats are typically constructed of 3 layers: the outside being a work surface of some plastics composition and the middle is the conductive portion. What was done in the video was not a valid test. He should have used a surface charge meter to measure. The whole idea is to bleed off any charges, not to 'short' them at the work surface. The middle layer of the work mats is made up of a carbon weave and yes, it conducts. Folks also need to know that these mats need to be grounded or they're useless. Many times in dry weather, I've gotten up from my chair and placed my hand at the edge of the mat to be greeted with a nice zap every so often. Shocking! Larry
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Re: Using nanoVNA to measure the directivity of a directional coupler
tuckvk3cca,
Thanks for the feedback. I finally was able to find a directivity specification of 20 dB minimum for the Narda 3060-20 on the web, which is in agreement with my measurement made using the nanoVNA. My best directional couplers have a 40 dB directivity. The ones I own with a directivity below 20 dB I only use for indicative purpose.
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Re: Advice sought on specific measurement.
For evaluating cables I normally just do a S21 log measurement, which is somewhat of a "catch all" test for losses due to impedance problems, cable defects etc. I only calibrate with a "through" measurement (with a union connector in place where the CUT will eventually be placed). Then I make the S21 log measurement with the cable being tested in place (where the union connector was during the through calibration). The frequency range depends on the needs...but higher frequencies near the nanoVNA upper limit will certainly be more sensitive in terms of detecting differences in cable performance.
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Re: Will a nanoVNA work above 1500MHz?
Further investigation did show the dsp algorithm fails to detect the intended signal but locks on a different harmonic so only thru measurement with a filter that removes unwanted fundamentals and other marhonics may ever be possible.
On similar hardware (SI5351, resistive bridge and 3*SA612, but much more selective dsp filter) I was able to have 20dB dynamix range at 2GHz but also there the bridge lost most/all directivity.
I guess for now impedance measurement at 2GHz will not be feasible with a nanoVNA
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Re: Using nanoVNA to measure the directivity of a directional coupler
30dB is rather low for 10MHz. I can get 53dB at 10MHz and 37dB at 35 MHz but this was not measured with the nanoVNA.
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Re: Using nanoVNA to measure the directivity of a directional coupler
At step 3 you can also use a shorted load. Then you have directivity for short. The two should be close about 0.5 dB. Also reverse IN and OUT to check symmetry.
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Re: Will a nanoVNA work above 1500MHz?
Thank you for the link.
I could not run the program. Many of the menue options do not respond.
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Advice sought on specific measurement.
I want to use my NanoVNA to determine if the cables I use in my lab are good enough, like the correct Z, no sharp bends or crushed dielectric or bad connectors, and so on.
My first vague idea was to
1. Calibrate solt for a plane at the end of a short cable.
2. Connect the cable under test, the CUT, to the end of the short cable in 1.
3. Connect something, (short, open, load?) at the end of the CUT.
And then know what a perfect CUT with Zc= the load test R would look like on the NanoVNA display.
And that I don't know.
Can you advice on this?
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Hi Rune , I get the last version , and I will test the average function as son as possible.
Many thanks for the very good application . Next week I wil measure a notch FM filter
using the nanoVNA using nanosaver , and also an hp8752B . I will compare the measures
and post the graphics.
Best regards
Maurizio IZ1MDJ
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Hi Rune Absolutely an enjoyment to use. Keep up the good work Have not yet tried the calibration, will do. Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af Rune Broberg Sendt: 22. september 2019 09:26 Til: [email protected]Emne: Re: [nanovna-users] NanoVNA Saver Hi Kurt, thank you for trying out the app! I'll certainly consider a way to lock the markers out of mouse control. I'm looking into zooming/scaling of the plots, but I don't have a great solution figured out yet. I hope you enjoy using the software :-) -- Rune / 5Q5R
On Sat, 21 Sep 2019 at 11:58, Kurt Poulsen <kurt@...> wrote: Hi Rune
V0.0.10 works fine, thank you.
May I suggest that the selection dots for the markers had a toggle
function such that when these was not marked the were locked and when
marked the marker was moveable. Alternative a further line called lock
markers. My eager right hand fingers hit very often the left mouse key
and the active marker is suddenly somewhere else.
Also if the vertical unit were scaleable would be nice e.g. to have
selectable dB ranges in steps or freely selectable. Same applies for
polar plot to e.g. to be able to study a load close in if inductive or
capacitive or both.
Kind regards
Kurt
-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af
Rune Broberg
Sendt: 18. september 2019 22:36
Til: [email protected]
Emne: Re: [nanovna-users] NanoVNA Saver
I just released 0.0.10:
It's not the most exciting release, but it offers some quality of life
improvements, such as the ability to choose the font size
(particularly useful for Linux users, whose default is a massive 11 pt font).
It also adds debug logging: -d to get log messages to the terminal, or
-D filename.txt to log to a file. Useful if you see crashes!
Additionally, it now supports importing magnitude/angle touchstone
files, and there's been a number of little bugfixes.
As ever, I look forward to hearing what bugs you find, and what new
features you want! :-)
--
Rune / 5Q5R
On Wed, 18 Sep 2019 at 18:05, hwalker <herbwalker2476@...> wrote:
Rune,
The new "Using the software" section on your GitHub page (
) is much appreciated! The
new pip installation also is nice, although on Windows I prefer to
just download your release and run the executable from my "C:\NanoVNA" directory.
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Re: Finger tightening SMA connections
If you get the "thin sma spanner tool" at like 3-4 GBP from sdr-kits, and
you have a dynamometer capable of measuring 6N accurately, you can actually
get a fairly accurate .3 Nm pulling at the tiny hole with the spanner
attached to an SMA collar nut, the spanner as vertical as possible and
pulling the dynamometer horizontally.
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Hi Steve,
as I see Herb has informed you already, there's currently no executables
for the 10a-version, which is my development branch. "a" at the end
generally indicates that it's between releases - I've started doing this
just to keep track of what app I'm myself running when checking for bugs ;-)
If you do wish to run the latest, greatest (and most unstable!) version,
the readme contains very superficial instructions. It requires having
Python 3.7 and git installed, and knowing how to use it is a good idea. For
most users, at the rate I'm currently managing to make releases, I
recommend waiting for the .exe.
These features should be out in a proper release within the next 48 hours.
:-)
--
Rune / 5Q5R
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On Sun, 22 Sep 2019 at 00:55, WB8GRS <ssedgwick@...> wrote: hwalker,
Where do you find NanoVNA Saver 0.0.10a.exe ? I went here:
and see 0.0.10 but not
0.0.10a. Would love to have the whole screen fit in my 1366X768 screen.
Rune,
Thank you so much for fitting the whole screen into a 1366x768 screen.
That will really make the NanoVNA Saver software so much easier to use.
Thanks,
Steve_WB8GRS
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Hi Maurizio,
thank you very much! Exactly the kind of thing I was looking for. It seems
my current implementation in the development version isn't far off from
what Keysight do; though I do need to set up the IIF/IIR for
continuous/live sweeping.
--
Rune / 5Q5R
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On Sat, 21 Sep 2019 at 23:48, Maurizio IZ1MDJ <redifon500@...> wrote: Hi , I found some info about the smoothing and average on Keysight network
analyzer at this link :
Best regards
Maurizio
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Hi Herb,
thank you for the feedback and the suggestion. It's good to hear that it's
starting to fit on 1366x768! I have received other comments indicating that
being able to store "comments" about sweeps was a desired feature, and I'll
definitely look at adding it. The charts should all have some room at the
top for a header as well. :-)
--
Rune
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On Sat, 21 Sep 2019 at 23:19, hwalker <herbwalker2476@...> wrote: Rune,
I just checked out your Latest commit, 0.0.10a and loving the fact that on
my 1366x768 display I can see the whole screen without needing scrollbars.
All the charts size very nicely at font size 7, even with show data
turned. I think the pop up windows for Files, Calibration, Display setup,
and About are nicely thought out. I wish at some point in the future you
could add a setting under "Display setup" that would allow the user to add
a centered caption at the top of the graphs for documentation purposes.
Keep up the great work!
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Hi Logan,
thank you for the suggestion. Implementing "bold" probably wouldn't be a
big problem. I have previously implemented "scaling" for high def monitors
on advice of other users, which should allow operating system scaling to
work without major problems, at least for Windows. I make no promises, but
you might have a look at this in the meantime?
Also, thank you very much for suggesting that I'm getting close to positive
integer major version territory - at times, I still feel very far off ;-)
--
Rune / 5Q5R
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On Sat, 21 Sep 2019 at 23:09, kz6oscar <lrahnz@...> wrote: Rune,
Thanks for all of your work on this. I know from personal experience the
effort and dedication that something like this requires. When I bought my
NanoVNA, I had no idea that I was "surfing" the early adopters wave. I am a
recently retired electrical engineer and the intellectual stimulation has
been welcome, especially when dealing with a well designed software
application like yours. The "bleeding edge" apps are not always this well
thought out. It is quickly getting to the point where the first digit of
the version number can be an integer greater than zero.
I do have a suggestion....
I have a 4k UHD monitor and one of the issues that I have is that most
apps use fonts that have a single pixel stroke width which can be quite
hard to read. I know that you have a font size option, which helps,
however, I found that simply going to the Bold version of a font can widen
the font stroke width and make big improvements in readability on a UHD
monitor without changing the font size. Perhaps, you could put this option
on your to do list for a future version.
73
Logan, KE7AZ
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Hi Jim,
I've studied the file, and it seems the same values were used for the
different calibration standards (OSL as well as I&T).
In a fit of poor design philosophy, I initially elected *not* to let the
buttons in the calibration screen run the sweep for you, but to expect the
user to do this manually for each standard before pressing the respective
button. It's become blatantly clear that this is completely unintuitive,
and I'll be looking at changing it - but for now, when you want to use
in-app calibration, make sure that you run a sweep for each standard, and
after each, press the relevant button in the calibration window. That's
currently the only way to get a valid in-app calibration.
I'll make a better interface for it, but it probably won't be for a couple
of releases (ie. not this coming week ;-)
--
Rune / 5Q5R
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On Sat, 21 Sep 2019 at 22:33, <jimcking@...> wrote: Hi Rune,
Attached is the calibration File.
Thanks Again.
Jim K. K8SLC
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Oristo
F4WCV
Kurt Poulsen