开云体育

Hello,

I've been using my Nano VNA as stand alone for a while and have recently started using the Nano VNA saver software for windows. I really like the software and find it very useful.

I've been using it with calibration made on the actual VNA itself, but have noticed that I can do it via the software also, which I thought might be worth doing. I didn't do it as I note the software suggests that it's actually better not to and rather calibrate via the VNA itself.

Does anyone have any input on this? I had hoped to create several calibration sweeps and save them via the software to make things easier to recall, plus being able to recall many scenarios.

Thanks,

yes, once you have calibrated in SAVER, you can store it on the laptop or
PC for future use.

Dave - W0LEV

--
Dave - W?LEV

I've had the same question for some time, but never bothered to ask. I've always just calibrated directly on the VNA because of what NanoSaver says.

Dave, can you please elaborate? Or anyone else? Why does the software have the waring/suggestion that it's calibrations be done directly on the NanoVNA?

Saver reads the values from the nano as they are. If the nano is
calibrated, Saver gets calibrated values. If you reset or disable the
calibration on the nano, Saver will get uncalibrated data. Saver has no
way of knowing which it is.

Any calibration done in Saver is done 'on top of' the data from the nano.
So at first glance it would seem that turning off calibration in the nano
would be the right thing to do when calibrating within the Saver app. And
indeed this does work very well, at least for some of us. The catch is
that Saver's software wants to see well-behaved data points, within the
expected data range of -1 to 1 (if I remember correctly). But some nanos,
due to variations in component tolerances in the nano hardware, will
sometimes emit data values a bit outside that range. Save does not deal
with this, and will crash or otherwise misbehave.

So the Saver authors recommend calibrating the nano (usually over a broad
freq range that encompasses your needs) to avoid this issue. You can then
do additional layers of calibration in Saver, including the very useful
feature of multiple segments to multiply the number of points.

But if you try it on your nano and it works correctly for your scenario,
using Saver with the nano's calibration turned off is a good (better?) way
to go. It is then calibrating raw data, and there is no concern about
compatibility of the frequency range used to calibrate the nano vs that
used in Saver.

so then, try calibrating from the saver program... and if it crashes, try first to calibrate from the device itself? :)

Yes, that should work. Note that to get uncalibrated data from the nano,
you need to reset the calibration, since it always powers on with whatever
state is in save slot 0. That is why many find it easier to save a wide
calibration in slot 0, e.g. 50kHz to 900M or whatever your nominal total
range, and just use that with Saver. I think that is the idea behind the
Saver author's statement of calibrating the nano first.

"I have noticed that I cannot run the vnaSaver program (Windows 11) when more devices based on STM32 processors are connected to the USB ports (e.g., STLink and others with CDC). Only disconnecting them helps. Is there any remedy for this?