I was fortunate enough to get some high-quality PTFE (Teflon) coax (RG-174 sized) SMA to BNC jumpers - and these hold up much better, probably because they have a small piece of heat-shrinkable tubing at the interface between the connector and the cable which distributes stress over a larger area. "Heavy" use of these good cables does eventually fatigue the shield or center conductor and make them unreliable - but they are still quite rugged.
If I could, I would put more heat-shrinkable tubing on them, but this is difficult with the already-attached connectors. One thing that I have done on cables like this is to put a shaped blob of "Shoe Goop" or equivalent adhesive to form a flexible "boot" at the transition point: A bit uglier than heat-shrink tubing, but similar in effectiveness in de-stressing the cable at that point.
73,
Clint
KA7OEI
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Re: Integration of a nanoVNA unit into an antenna system as indicator of resonance frequency
This is how I am driving the Mag loop
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Is there any documentation on the formulas used by the NanoVNA to calibrate and correct measurements?
Hello,
I am looking for any references that explain the formulas used by the NanoVNA to do calibration and measurement corrections. I have looked at various six- and twelve- parameter corrections. Does the NanoVNA use these methods? I have looked at the DG8SAQ documentation and then derived my own method based on that. I am curious to how the calibration on the NanoVNA will be affected by various fixtures.
73,
Dan
KW4TI
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Re: Integration of a nanoVNA unit into an antenna system as indicator of resonance frequency
Hi
I used the following approach with my mag loops.
Capacitor is driven by a stepper motor controlled remotely (Arduino + Nrf24l01 module)
When I decide to have a QSO session, I first run a calibration.
I move automatically from begin to end of the relevant band by small steps and each time measure the resonance frequ (S11 dip)
At the end I get an x,y table where x are the resonance frequencies, and y the corresponding stepper positions.
I then compute the table to obtain the function stepper pos= f(frequency) (Polynomial interpolation)
All above is carried out automatically (Python script running on a headless Raspberry PI including a Web Interface)
In this way I can move very fast within the band without having to tune each time.
(frequency is read via CAT interface and stepper is then moved to the new position)
Currently developing a solution for the Ciro Mazzoni loop which is driven by a linear piston.
Positioning of the piston will be done by means of a fix rotary encoder (600 counts/360¡ã) driven by a small 3d printed rack.....
Will soon share some pictures!
73 de HB9IIU
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Hi all,
regarding saving the scan and download it later, I think a nice firmware feature would be to schedule a delayed scan followed by a pause after the scan.
This will allow to hang the NanoVNA to the antenna (for example HF multiband dipole like FD4, or VHF YAGI) and perform a scan without the feeder.
The delayed start of the scan is necessary to allow enough time to install the antenna in the position.
Thank you,
Ady (YO2NAA)
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Re: Integration of a nanoVNA unit into an antenna system as indicator of resonance frequency # improvements
Check out the ModularTuner
This is an automatic antenna tuner with a directional coupler that you
could program to search for the minimum SWR. It can be easily integrated
into an antenna system as the directional coupler is placed in-line and you
can have the microcontroller switch relay units that adjust inductors or
capacitors, for example. The two modules you would need are the
DirectionalCoupler and the Controller. The controller measures the
amplitude and phase of the reflection coefficient.
73,
Dan
KW4TI
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On Sun, Nov 3, 2019 at 8:40 AM Wolfgang Kiefer <woki@...> wrote: Hi Arno,
in my EU1KY analyzer I have implemented a function to search the minimal
SWR. This is no problem for the software designers!
And a good idea for implementing a new function.
Best regards,
Wolfgang, DH1AKF
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As a first step I will model the reference Z0 ( normally 50 ohm ) as a RLC combination
If that is not enough I will add some unbalance to the moebius transform.
--
Erik, PD0EK
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Re: Problem installing NanoVNA saver on Ubuntu 18.04LTS...
Ian,
try: python -m pip install --user --upgrade pip
and next PyQT5 install
I hope help
Gyula, HA3HZ
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Hi Oristo When the cal kit calibration kit is loaded in the VNWA software you simply open a custom trace and in the Expression line write s_load or s_open or s_short or s_thrumatch or s_thru then the trace is shown according for the custom trace to be shown as you like in Smith, dB of what ever representation and then to save directly as s1p file by a right click on the trace and use the "Export to s1p file" function. You must decide on frequency span and number of points in advance Simpe as that ? Kind regards Kurt Fra: [email protected] < [email protected]> P? vegne af Oristo Sendt: 3. november 2019 20:42 Til: [email protected]Emne: Re: [nanovna-users] Chasing ghosts??? #internals #calibration Thanks for the links.! One problem is that scikit-rf wants S11 files for ideal SOL but I did not find how scikit-rf can generate S11 from e.g. delay, R, L, C values. Since I have SDR-Kits BNC cal kit, perhaps S11 for those can be generated using VNWA software, but scikit-rf also seemingly does no interpolation; raw measurement frequencies must match ideal S11, so that will be another challenge.
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I'm trying to create a VNA error model
to compensate for errors in the bridge and the Z0 reference This "deembedding" may do it:
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Re: Problem installing NanoVNA saver on Ubuntu 18.04LTS...
Rune,
I've put the machine to bed for today so I will revert tomorrow with version number of installed PyQt5.
What I can say is that I removed the # before the version checker before I did that install - so I might put that back in again to see what it thinks once more.
Many thanks for your assistance. I'll revert with a more coherent report tomorrow.
Best regards,
Ian
--
Amateur Radio Station G8OGJ
Matlock, England
g8ogj.org
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The Google translate to Danish requires a special study edy555 basically calibrated with the test jig as if ideal
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Thanks for the links.! One problem is that scikit-rf wants S11 files for ideal SOL but I did not find how scikit-rf can generate S11 from e.g. delay, R, L, C values. Since I have SDR-Kits BNC cal kit, perhaps S11 for those can be generated using VNWA software, but scikit-rf also seemingly does no interpolation; raw measurement frequencies must match ideal S11, so that will be another challenge.
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Hi Oristo Than you for an interesting link. The Google translate to Danish requires a special study ? but I will give it a try Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af Oristo Sendt: 3. november 2019 17:41 Til: [email protected]Emne: Re: [nanovna-users] Measuring ferrite beads #test-jig That VNA stuff appears to be more critical to what I was aware of. The technique of nanoVNA designer edy555 is worth reviewing: "Remove the crystal filter and connect the resistors to get through characteristics. Next, disconnect the resistors and take isolation characteristics, and CAL DONE in that state. In this case, the loss due to resistance and the leakage due to wiring and jigs are cancelled." <>
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I'm trying to create a VNA error model to compensate for errors in the bridge and the Z0 reference
Yes. Results match nanoVNA firmware
Thanks for the links.!
--
Erik, PD0EK
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Re: Problem installing NanoVNA saver on Ubuntu 18.04LTS...
Hi Ian,
what version did you install directly from Ubuntu? NanoVNA-Saver should run
with that, assuming it's PyQt5 and not PyQt4 - but I haven't tried it with
older versions.
There's nothing in NanoVNA-Saver that requires 64 bit - PyQt5 is the user
interface library I used, because it's what I usually use when I build
small applications for myself - and that's all that NanoVNA-Saver was at
the start. ;-) It's available in a 32 bit version for Windows, so quite why
it's not available for 32 bit Linux I don't know.
--
Rune / 5Q5R
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On Sun, 3 Nov 2019 at 19:37, Ian Beeby <ian@...> wrote: Rune,
I've tried that and you are right, even removing the version requirement
altogether results in an error. I have tried to install PyQt5 directly
from Ubuntu and, while the basic OS install seems to work, the pip install
failed with an error which effectively said cannot find an appropriate
version which I took to mean could not find any version.
So I suppose that I am stuck unless the pip developers see fit to do a
32-bit version of PyQt5? Is there any fundamental reason why NanoVNASaver
needs 64-bits?
Ian
--
Amateur Radio Station G8OGJ
Matlock, England
g8ogj.org
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Re: Problem installing NanoVNA saver on Ubuntu 18.04LTS...
Rune,
I've tried that and you are right, even removing the version requirement altogether results in an error. I have tried to install PyQt5 directly from Ubuntu and, while the basic OS install seems to work, the pip install failed with an error which effectively said cannot find an appropriate version which I took to mean could not find any version.
So I suppose that I am stuck unless the pip developers see fit to do a 32-bit version of PyQt5? Is there any fundamental reason why NanoVNASaver needs 64-bits?
Ian
--
Amateur Radio Station G8OGJ
Matlock, England
g8ogj.org
|
Re: How to make Nano VNA Saver fit the full screen without using vertical scrollbars
Hi Sam,
what operating system are you using? I have tested 0.1.4 on a virtual
machine with a 1366x768 screen, and it fits without scroll bars - *just* -
with the default setup, on Windows 7, at font size 8. :-)
--
Rune / 5Q5R
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On Sun, 3 Nov 2019 at 18:38, Sam Reaves <sam.reaves@...> wrote: Hello,
Is there a way to configure NanoVAN Saver so that the entire Window fits
the screen? My Screen resolution maximum on my HP laptop is 1366 X 768
Thanks,
Sam W3OHM
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Re: Problem installing NanoVNA saver on Ubuntu 18.04LTS...
Hi Ian,
you can try replacing the "==" in setup.py with ">=" - seeing if there's a
newer version. If that fails, try removing the version requirement entirely
- but I don't think there is a version of PyQt5 for 32 bit linux in the pip
repository.
--
Rune / 5Q5R
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On Sun, 3 Nov 2019 at 18:43, Ian Beeby <ian@...> wrote: I've tried to repeat the install and note that after the command
"python3.7 -m pip install ." I get the following error message (between the
***s):
***
Could not find a version that satisfied the requirement PyQt5==5.11.2
(from NanoVNASaver==0.1.4) (from version: )
No matching distribution found for PyQt5==5.11.2 (from NanoVNASaver==0.1.4)
***
The error is in red.
I'm presuming, therefore, that there is a version requirement in
NanoVNASaver that my version of Ubuntu does not support. Is anyone aware
of precisely what that requirement does? Is there an older version that I
might start with? Can I upgrade my version of PyQt5?
Ian
--
Amateur Radio Station G8OGJ
Matlock, England
g8ogj.org
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All date is measured uncalibrated and loaded into Octave.
Calibration is done in Octave so all calculations are identical Octave calibration lacks a bridge compensation model? Results for nanoVNA match those done by its firmware? I cannot sort whether scikit-rf has a more elaborate model:
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Gyula Molnar
Kurt Poulsen
Oristo