On Mon, 28 Apr 2025 at 22:25, Dean W8ZF via groups.io <dwfred=
[email protected]> wrote:
Dragan,
This just confuses me again.
"Remove the calibration and save that to the default slot (0 slot) when
using NanoVNA Saver."
Remove *which* calibration? And save *what* to slot 0? Are you talking
about the H4 device? Do you mean from the calibrate menu, choose "Reset"
and then "Save" to memory 0?
What values does this put into memory 0? And since nanovna-saver depends
on the calibration of the H4 device, what is that calibration now (after
reset and store 0)?
Yes, memory 0 should store the uncalibrated state, essentially no
calibration. Saver takes whatever the device gives it, there is nothing in
the serial protocol commands that deal
with calibration data.
"When you calibrate the Nano (on device calibration) in the range as the
documentation suggests 0-900MHz with 401 points..."
Where is there an option on the H4 device to select the number of points
used for calibration? I haven't seen that as a menu option.
I believe that it takes the number of points set on the device. I never use
the device standalone so I don't remember which option it is.
If the calibration of nanovna-saver gives different results, depending on
the state of the H4's calibration, I don't know what to believe.
It's simple: NanoVNA has a simple serial protocol, you can set the
basic parameters, request the scan etc. If your on device calibration
is completely off you will get bad results without or with Saver
calibration since it's working with bad data from the start.
Forgive me, I still don't understand how this works together. I don't see
why nanovna-saver can't just read raw results from the H4, and then use
those for a calibration (which would make it independent of the H4's
calibration). There have been some mentions about different numbers of
points, about reporting invalid values, etc.
It can, that is why I said that you should store the uncalibrated state
in slot 0. Number of points, BW etc will be set via the serial commands
from the Saver side.
Does anyone KNOW, not guess, what the proper procedure to calibrate this
system using nanovna-saver is? Nanovna-saver is what it is, I'm not
bashing it or trying to change it -- I'm just trying to understand the
limitations and requirements to get good results out of the software. The
ability to store calibrations, write s-parameter files, and plot using
different formats is invaluable to me. I *really* want to use it for these
features, but not if I can't be sure of the measurement.
It really isn't that complicated, it becomes pretty obvious when you
examine the NanoVNA serial protocol documentation.
