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I use nanovna-saver with my H4 because it aggregates several useful functions for operating, storing, printing, and exporting measurements. I am confused about the calibration done from nanovna-saver. I know I can load and save calibrations on my PC as files. This works and I use it all the time. I wanted to take the H4 out to the yard and do measurements at the antenna after I calibrated with nanovna-saver. It seems that it did not retain the calibration. I don't remember if I had turned the H4 off, then back on, but the results were different when I then brought out my laptop and loaded my calibration file. Everything seemed to measuring correctly, after that. So I have some questions;
1) What is the persistence of calibration done through nanovna-saver? I.e., does it persist if the USB cord is disconnected and the H4 is taken for mobile measurements?
2) Is the calibration done by nanovna-saver dependent on the calibration done by the H4's internal cal? For instance, say memory #0 on the H4 has a bad calibration stored. Since this is the default used by the H4 when it boots up, will it corrupt the calibration done in nanovna-saver. Does nanovna-saver depend on the calibration state of the H4 to be correct?
3) Is is possible to store the calibration done in nanovna-saver to one of the memory states in the H4? Storing it in memory #0 would allow for a calibration to be persistent through a power cycle.

Thanks and 73,
Dean W8ZF

#2 is correct.
The calibration done in nanovna-saver is solely in the computer. It can't be saved to a slot in the nanovna, partly because -saver has more sweep-point options. You need to do the calibration on nanovna separately.

Also, it is important to note that (in ver. 0.4.0 and maybe others) the calibration done in nanovna-saver runs on top of the active calibration in the nanovna. [Some later version which I am not aware of may have a selection to use raw nanovna data.]

So it is important to save a basic broad calibration in nanovna slot 0, or a slot you will recall before each nanovna-saver calibration and use. Alternatively always reset or disable nanovna calibration while using nanovna-saver. [But sometimes -saver will get an error with the latter approach, due to out-of -range data from nanovna.]

QUOTE: 1) What is the persistence of calibration done through
nanovna-saver? I.e., does it persist if the USB cord is disconnected and
the H4 is taken for mobile measurements?

Any cal done within SAVER stays with SAVER. Any cal done on the native
NANOVNA stays with the NANOVNA. They do not cross pathes.
***

2) Is the calibration done by nanovna-saver dependent on the calibration
done by the H4's internal cal? For instance, say memory #0 on the H4 has a
bad calibration stored. Since this is the default used by the H4 when it
boots up, will it corrupt the calibration done in nanovna-saver. Does
nanovna-saver depend on the calibration state of the H4 to be correct?

The cals done on the native NANOVNA and within SAVER are independent of
eachother.
*

3) Is is possible to store the calibration done in nanovna-saver to one of
the memory states in the H4? Storing it in memory #0 would allow for a
calibration to be persistent through a power cycle.

The cals between the native NANOVNA and within SAVER are independent.
\

It's all like what happens in Vegas stays in Vegas.......

Dave - W?LEV


On Sat, Apr 26, 2025 at 2:49?PM Dean W8ZF via groups.io <dwfred=
[email protected]> wrote:

I use nanovna-saver with my H4 because it aggregates several useful
functions for operating, storing, printing, and exporting measurements. I
am confused about the calibration done from nanovna-saver. I know I can
load and save calibrations on my PC as files. This works and I use it all
the time. I wanted to take the H4 out to the yard and do measurements at
the antenna after I calibrated with nanovna-saver. It seems that it did
not retain the calibration. I don't remember if I had turned the H4 off,
then back on, but the results were different when I then brought out my
laptop and loaded my calibration file. Everything seemed to measuring
correctly, after that. So I have some questions;
1) What is the persistence of calibration done through nanovna-saver?
I.e., does it persist if the USB cord is disconnected and the H4 is taken
for mobile measurements?
2) Is the calibration done by nanovna-saver dependent on the calibration
done by the H4's internal cal? For instance, say memory #0 on the H4 has a
bad calibration stored. Since this is the default used by the H4 when it
boots up, will it corrupt the calibration done in nanovna-saver. Does
nanovna-saver depend on the calibration state of the H4 to be correct?
3) Is is possible to store the calibration done in nanovna-saver to one
of the memory states in the H4? Storing it in memory #0 would allow for a
calibration to be persistent through a power cycle.

Thanks and 73,
Dean W8ZF

--

*Dave - W?LEV*


--
Dave - W?LEV

Thanks for the replies. There seems to be some disagreement on #2. Appparently for some versions (maybe all), the cal in nanavna-saver IS dependent on the H4 being in a calibrated state before the nanovna-saver cal is performed. I can do the H4 internal cal, no problem, but what happens when the sweep range is different for nanovna-saver than the H4's stored cal? Are results invalid, or are they interpolated (assuming nanovna-saver is sweeping in a sub-range of the H4's calibrated range)?

QUOTE: ........ but what happens when the sweep range is different for
nanovna-saver than the H4's stored cal? Are results invalid, or are they
interpolated (assuming nanovna-saver is sweeping in a sub-range of the H4's
calibrated range)?

When you do a cal in SAVER, there is an option to clear all previous cals.
This SHOULD BE EXERCISED to assure a clean and meaningful new cal.

When you change the sweep width, it is always an excellent idea to do a new
cal dedicated to the new intended frequency sweep range. If the "new"
range is greater than the previous cal range, the instrument will use the
cal but interpolate between cal points. This potentially will introduce
extrapolation errors which could have been avoided by doing a dedicated new
cal over the "new" intended frequency sweep range. When changing sweep
ranges it's ALWAYS a good practice to run an additional cal dedicated to
the new range. This also applies to "professional" (and very expensive)
VNAs.

Dave - W?LEV

On Sat, Apr 26, 2025 at 3:59?PM Dean W8ZF via groups.io <dwfred=
[email protected]> wrote:

Thanks for the replies. There seems to be some disagreement on #2.
Appparently for some versions (maybe all), the cal in nanavna-saver IS
dependent on the H4 being in a calibrated state before the nanovna-saver
cal is performed. I can do the H4 internal cal, no problem, but what
happens when the sweep range is different for nanovna-saver than the H4's
stored cal? Are results invalid, or are they interpolated (assuming
nanovna-saver is sweeping in a sub-range of the H4's calibrated range)?

--

*Dave - W?LEV*


--
Dave - W?LEV

Dave, correct information, but you did not address his real question: Is the nanovna-saver 0.4.0 calibration dependent on the nanovna internal cal?

I was taught (back a couple of years ago) that nanovna-saver reads the calibrated data from the nanovna. So on nanovna, you should do a wide-range calibration, and use that cal whenever you use nanovna-saver calibrations - both during the nanovna-saver calibration, and for all measurements with nanovna-saver. Alternately, you could reset/disable the nanovna calibration whenever you use nanovna-saver, but sometimes that caused problems due to an out-of-range raw data value from nanovna. Back at that time, I verified that this was correct.

Has nanovna-saver been changed to read the raw data and deal with the out-of-range problem? Not that I am aware of. [But then I mostly use nanovna-app nowadays.]

And Dean, in answer to your question, if you always use the same nanovna cal when using nanovna-saver, no nanovna change is necessary when you change ranges, etc. and calibrate in nanovna-saver. This is because the nanovna-saver calibration compensates for whatever it sees in the data from nanovna. Ideally, the nanovna calibration will have a wide frequency range which is a superset of the frequency ranges that you will use in nanovna-saver.

No. They are independent.

Dave - W?LEV

On Sat, Apr 26, 2025 at 5:00?PM Stan Dye via groups.io <standye=
[email protected]> wrote:

Dave, correct information, but you did not address his real question: Is
the nanovna-saver 0.4.0 calibration dependent on the nanovna internal cal?

I was taught (back a couple of years ago) that nanovna-saver reads the
calibrated data from the nanovna. So on nanovna, you should do a
wide-range calibration, and use that cal whenever you use nanovna-saver
calibrations - both during the nanovna-saver calibration, and for all
measurements with nanovna-saver. Alternately, you could reset/disable the
nanovna calibration whenever you use nanovna-saver, but sometimes that
caused problems due to an out-of-range raw data value from nanovna. Back
at that time, I verified that this was correct.

Has nanovna-saver been changed to read the raw data and deal with the
out-of-range problem? Not that I am aware of. [But then I mostly use
nanovna-app nowadays.]

And Dean, in answer to your question, if you always use the same nanovna
cal when using nanovna-saver, no nanovna change is necessary when you
change ranges, etc. and calibrate in nanovna-saver. This is because the
nanovna-saver calibration compensates for whatever it sees in the data from
nanovna. Ideally, the nanovna calibration will have a wide frequency
range which is a superset of the frequency ranges that you will use in
nanovna-saver.

--

*Dave - W?LEV*


--
Dave - W?LEV

Thanks Dave,
So if the H4 internal cal is *independent* of the nanovna-saver cal, exactly what are you clearing with nanovna-saver's "clear all cals"and when would that be necessary?
I ALWAYS either calibrate prior to measurements (and upon any sweep range or source power change) or I alternatively load a saved calibration file generated by nanovna-saver. Doesn't using the calibration assistant or loading the cal file "clear all cals"?

I understand the principles and use of a VNA. I'm a Senior Principal RF engineer and have used professional VNAs for 45 years. But I am new to the nanovna VNA implementation and the interactions of the H4 with software interfaces. What would be the source of information on whether nanovna-saver uses raw data from the nanovna as part of its calibration, nor not? I can always use the internal calibrate routine in the H4 for mobile use, it looks like that's necessary (since the nanovna-saver cal data is independent). But I am still not convinced that I can trust nanovna-saver's calibration (because MAYBE it depends on the H4's cal state).

Thanks and 73,
Dean W8ZF

And thank you, Stan, for your feedback!
73,
Dean W8ZF

On Sat, Apr 26, 2025 at 10:39 AM, Dean W8ZF wrote:

because MAYBE it depends on the H4's cal state

From the nanovna-saver github readme ():
Quote:
Calibration

Before using NanoVNA-Saver, please ensure that the device itself is in a reasonable calibration state.

A calibration of both ports across the entire frequency span, saved to save slot 0, is sufficient. If the NanoVNA is completely uncalibrated, its readings may be outside the range accepted by the application.

-------------
And from the code itself, the following code fragment shows that nanovna-saver uses the "scan" command, rather than the "scanraw" command, to get its data from nanovna. The "scan" command returns S11/S12 data with nanovna internal calibration (if any) applied.

def setSweep(self, start, stop):
self.start = start
self.stop = stop
list(self.exec_command(f"scan {start} {stop} {self.datapoints}"))
-------------

So nanovna-saver indeed does depend on the calibration state of the nanovna; they are not independent.
Q.E.D.

If you want independent calibration, use nanovna-app instead. It is a quite different application with its own learning curve, but it has specific settings to use the nanovna internal or nanovna-app calibration. I use both apps, they both have excellent features.

Stan KC7XE

Thanks, Stan!
This is definitive and helps me understand what to expect. I'll try nanovna-app, to see what that's about. I'm a little surprised that nanovna-saver depends on the H4's calibration state, but the code is the code! (Unless they change it, LOL.)
73,
Dean W8ZF

On Sat, Apr 26, 2025 at 02:06 PM, Dean W8ZF wrote:

I'm a little surprised that nanovna-saver depends on the H4's calibration
state

They did that to avoid some problems that require extra coding. And since you can do one calibration from 50kHz to 900MHz, and save it in slot 0, you never have to revisit it. The problem is that nanovna can output S11/S21 values outside the range 0<=x<=1 if it is not calibrated - which causes arithmetic errors with any normal S11/S21 processing algorithm. And if you calibrate it first, the nanovna does not do that (except maybe under rare conditions). And it doesn't matter so much what the nanovna calibration is - it just needs to be there and be consistent - because the 'working' calibration is that done by the nanovna-saver algorithm.

Yes, if your SAVER is miles outside of your intended cal range, you need to
do a cal on the native device first. I've never had that problem, so I
wouldn't know. I've used professional VNAs for decades on the job (I'm now
retired) and own an HP 8753C, so I really didn't have to even open the
instruction book. Please forgive me.......

Dave - W?LEV

On Sat, Apr 26, 2025 at 6:17?PM Stan Dye via groups.io <standye=
[email protected]> wrote:

On Sat, Apr 26, 2025 at 10:39 AM, Dean W8ZF wrote:

because MAYBE it depends on the H4's cal state

From the nanovna-saver github readme (
):
Quote:
Calibration

Before using NanoVNA-Saver, please ensure that the device itself is in a
reasonable calibration state.

A calibration of both ports across the entire frequency span, saved to
save slot 0, is sufficient. If the NanoVNA is completely uncalibrated, its
readings may be outside the range accepted by the application.

-------------
And from the code itself, the following code fragment shows that
nanovna-saver uses the "scan" command, rather than the "scanraw" command,
to get its data from nanovna. The "scan" command returns S11/S12 data
with nanovna internal calibration (if any) applied.

def setSweep(self, start, stop):
self.start = start
self.stop = stop
list(self.exec_command(f"scan {start} {stop} {self.datapoints}"))
-------------

So nanovna-saver indeed does depend on the calibration state of the
nanovna; they are not independent.
Q.E.D.

If you want independent calibration, use nanovna-app instead. It is a
quite different application with its own learning curve, but it has
specific settings to use the nanovna internal or nanovna-app calibration.
I use both apps, they both have excellent features.

Stan KC7XE

--

*Dave - W?LEV*


--
Dave - W?LEV

Dave,

Does the NanoVNA come with an instruction manual?

I received only a menu chart, and no other booklet.

73

Jon, VU2JO

On Sun, Apr 27, 2025 at 3:45?AM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

Yes, if your SAVER is miles outside of your intended cal range, you need to
do a cal on the native device first. I've never had that problem, so I
wouldn't know. I've used professional VNAs for decades on the job (I'm now
retired) and own an HP 8753C, so I really didn't have to even open the
instruction book. Please forgive me.......

Dave - W?LEV

On Sat, Apr 26, 2025 at 6:17?PM Stan Dye via groups.io <standye=
[email protected]> wrote:

On Sat, Apr 26, 2025 at 10:39 AM, Dean W8ZF wrote:

because MAYBE it depends on the H4's cal state

From the nanovna-saver github readme (
):
Quote:
Calibration

Before using NanoVNA-Saver, please ensure that the device itself is in a
reasonable calibration state.

A calibration of both ports across the entire frequency span, saved to
save slot 0, is sufficient. If the NanoVNA is completely uncalibrated,

its

readings may be outside the range accepted by the application.

-------------
And from the code itself, the following code fragment shows that
nanovna-saver uses the "scan" command, rather than the "scanraw" command,
to get its data from nanovna. The "scan" command returns S11/S12 data
with nanovna internal calibration (if any) applied.

def setSweep(self, start, stop):
self.start = start
self.stop = stop
list(self.exec_command(f"scan {start} {stop} {self.datapoints}"))
-------------

So nanovna-saver indeed does depend on the calibration state of the
nanovna; they are not independent.
Q.E.D.

If you want independent calibration, use nanovna-app instead. It is a
quite different application with its own learning curve, but it has
specific settings to use the nanovna internal or nanovna-app calibration.
I use both apps, they both have excellent features.

Stan KC7XE

--

*Dave - W?LEV*


--
Dave - W?LEV

No, it does not. However, there are several publications out that instruct
one on using the NANOVNAs. Once you learn the basics, that should map over
to any VNA, professional or NANO.

Dave - W?LEV

On Sat, Apr 26, 2025 at 11:06?PM Jon via groups.io <vu2jo0=
[email protected]> wrote:

Dave,

Does the NanoVNA come with an instruction manual?

I received only a menu chart, and no other booklet.

73

Jon, VU2JO

On Sun, Apr 27, 2025 at 3:45?AM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

Yes, if your SAVER is miles outside of your intended cal range, you need

to

do a cal on the native device first. I've never had that problem, so I
wouldn't know. I've used professional VNAs for decades on the job (I'm

now

retired) and own an HP 8753C, so I really didn't have to even open the
instruction book. Please forgive me.......

Dave - W?LEV

On Sat, Apr 26, 2025 at 6:17?PM Stan Dye via groups.io <standye=
[email protected]> wrote:

On Sat, Apr 26, 2025 at 10:39 AM, Dean W8ZF wrote:

because MAYBE it depends on the H4's cal state

From the nanovna-saver github readme (
):
Quote:
Calibration

Before using NanoVNA-Saver, please ensure that the device itself is in

a

reasonable calibration state.

A calibration of both ports across the entire frequency span, saved to
save slot 0, is sufficient. If the NanoVNA is completely uncalibrated,

its

readings may be outside the range accepted by the application.

-------------
And from the code itself, the following code fragment shows that
nanovna-saver uses the "scan" command, rather than the "scanraw"

command,

to get its data from nanovna. The "scan" command returns S11/S12 data
with nanovna internal calibration (if any) applied.

def setSweep(self, start, stop):
self.start = start
self.stop = stop
list(self.exec_command(f"scan {start} {stop}

{self.datapoints}"))

-------------

So nanovna-saver indeed does depend on the calibration state of the
nanovna; they are not independent.
Q.E.D.

If you want independent calibration, use nanovna-app instead. It is a
quite different application with its own learning curve, but it has
specific settings to use the nanovna internal or nanovna-app

calibration.

I use both apps, they both have excellent features.

Stan KC7XE

--

*Dave - W?LEV*


--
Dave - W?LEV

--

*Dave - W?LEV*


--
Dave - W?LEV

Jon,Look in the group files section. Lots of user information there.?

Yahoo Mail: Search, Organize, Conquer

On Sat, Apr 26, 2025 at 6:37 PM, W0LEV via groups.io<davearea51a@...> wrote: No, it does not.? However, there are several publications out that instruct
one on using the NANOVNAs.? Once you learn the basics, that should map over
to any VNA, professional or NANO.

Dave - W?LEV

On Sat, Apr 26, 2025 at 11:06?PM Jon via groups.io <vu2jo0=
[email protected]> wrote:

Dave,

Does the NanoVNA come with an instruction manual?

I received only a menu chart, and no other booklet.

73

Jon, VU2JO

--
Don ? K5ZRQ