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On Tue, Apr 29, 2025 at 06:28 AM, Brian Beezley wrote:

Something else I've wondered about. This is an 820 pF capacitor from 50 MHz to
4 GHz. There's not much to see. Would a magnification function be helpful? Or
do people just not worry about detail in this kind of plot?

Yes, magnification in particular around the Zo of the chart is quite useful and that is a feature available
on several simulators. Conversion from S to mS or even uS is also an automatic process to improve readability.

On the Z and Y chart. To clarify, Brian, they are OVERLAID. Both appear as a single chart. A toggle permits Z to be on/off and then
further toggle permits Y to be on/off while an additional toggle permits both ON.

Fundamental to LC matching is the arithmetic to convert from series Z to equivalent parallel Y. This can be accomplished
on a single Z chart. However, it is facilitated by displaying both charts Z and Y at the same time so that the SHUNT (Y) movement
is obtained from the admittance chart and SERIES (Z) movement is obtained from the impedance chart. By movement, I mean along
reactance or susceptance contours.

The whole point of displaying both impedance and admittance charts simultaneously is that it make visualizing matching much easier.

Adding series C moves CCW on the impedance chart, shunt C CW on the admittance chart
Adding series L moves CW on the impedance chart, shunt L CCW on the admittance chart

Other transforms are also visible.

73
Jeff G8HUL

________________________________________
From: [email protected] on behalf of Brian Beezley
Sent: Tuesday, April 29, 2025 13:56
To: [email protected]
Subject: Re: [nanovna-users] Smith Charts


Here's how it looks at the moment. I'm thinking of providing a different background color for admittance, but the grid is so different that I'm not sure that's necessary.

Brian

Something else I've wondered about. This is an 820 pF capacitor from 50 MHz to 4 GHz. There's not much to see. Would a magnification function be helpful? Or do people just not worry about detail in this kind of plot?

Brian

Here's how it looks at the moment. I'm thinking of providing a different background color for admittance, but the grid is so different that I'm not sure that's necessary.

Brian

On Tue, Apr 29, 2025 at 05:05 AM, alan victor wrote:

To facilitate matching the 2 charts are overlaid in 2 colors. The immitance
chart used red and green and the one I used had less density on contours.
Consider the possibility of a toggle between them.

I don't quite follow this. You click on Admittance to plot admittance. Otherwise it plots impedance. The grid and marker annotation change. The curves remain the same.

In looking at admittance for some filters renormalized to 1000 ohms, even mS was too small. Currently the marker annotation switches to microsiemens when the admittance magnitude is less than 10 mS. That threshold seems about right, but I may adjust it.

Brian

Here is a portion of the immittance chart. Less contour density is still workable.
A toggle feature is available on the program I use to assist in clarification.

Yes on mS.

To facilitate matching the 2 charts are overlaid in 2 colors. The immitance
chart used red and green and the one I used had less density on contours.
Consider the possibility of a toggle between them.

I've got the Smith admittance plot running. I assume people use mS rather than S to avoid tiny numbers. Is that right?

Brian

On Tue, Apr 29, 2025 at 02:25 AM, PE0CWK wrote:

my Windows 10 pc? finds a virus

It's a false positive.

First of all, download the latest security intelligence update from Microsoft. I just did, and it does not flag the file as a virus.

Another way to check is to give the URL () to VirusTotal:



It will analyze the file with about 100 virus checkers. Once you're satisfied the file is safe, disable your antivirus software, download the file, and then reenable virus checking. You may need to exclude the .exe files from antivirus scrutiny. See Exclusions here:



Brian

Brian,

F.y.i. When I click on the word program on your page then my Windows 10 pc? finds a virus and does not continue to download.

73, Kees PE0CWK

Op 29-4-2025 om 00:51 schreef Brian Beezley:

On 29/04/2025 04:21, Mark via groups.io wrote:

I have the NANO H4 connected to my laptop and the app is running. However,
I see next to the <DISCONNECTED> is a field where I am supposed to enter
an IP address?? I do not know the IP address or why it would need that.
Please explain.
Mark kd5smf

Mark,

How is your H4 connected? If a serial USB cable, then COM port number rather than IP address. Device Manager will show the COM ports you have.

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: davidtaylor@...
BlueSky: @gm8arv.bsky.social, Twitter: @gm8arv

Did you go through those calibration steps on the application or the Nano?
If on the application then you must be connected successfully.

You calibrate on the Nano only when you want to use it as a stand-alone device.

Best Wishes
Tony

Using nanaovna-saver, on a -f, I noticed that sometimes the circle on the Smith machine (on a simple capacitor, for example) could be larger than the grid circle.

Now, systematically, even before calibrating with nanaovna-saver, I perform a RESET on the case, which nanovna-saver doesn't seem to do (0.3.8 because W7). This RESET solves the problem.
--
F1AMM
Fran?ois

I have the NANO H4 connected to my laptop and the app is running. However,
I see next to the <DISCONNECTED> is a field where I am supposed to enter
an IP address?? I do not know the IP address or why it would need that.
Please explain.
Mark kd5smf

Why not have a serious read of the information in the WiKi on this site?
There are several excellent guides there.

Dave - W?LEV

On Mon, Apr 28, 2025 at 11:55?PM Dragan Milivojevic via groups.io
<d.milivojevic@...> wrote:

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.

--

*Dave - W?LEV*


--
Dave - W?LEV

It depends on how different the results are. Remember, the FW interpolates

between measured and stored cal values. Saver can be configured with 1001
points so the cal. sampling is much finer than a cal. on the native NANOVNA
(without SAVER).

***

Saver can do unlimited (in theory) number of points. It will just do
the required points
in segments. For H4 that would be X times 401 points to get to your desired
number of points.
Word of warning: Saver is a Python single thread software, after a certain
number of points it becomes
time consuming to process more that ~5K points on a single CPU core.

Again, using SAVER, there is the option to use considerably more points for
calibratioin: Native is 401 points, SAVER allows up to 1001 points. So
extrapolation between measured points using the two calibrations will be
coarser with the native VNA cal than with the SAVER cal.

Just avoid extrapolation: use the same frequency span when measuring as you
did when you calibrated ...

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.

I've posted the s-parameter Smith plotter here:



Please read splot.txt to learn the obscure tricks (like how to display a Smith plot!). I will try to free up some screen space for a dedicated Smith button.

I found so many bugs today and of so many kinds that I'm sure there must be some left. Please email if you spot something amiss. My email address is at the bottom of the page referenced above.

When I post a new version, the image at the top of the page will have an updated version number (it's in the upper left). You may have to Ctrl-refresh your browser to refresh your image cache.

Brian

On Mon, Apr 28, 2025 at 03:23 PM, Andreas Ott K6OTT wrote:

Am I reading this right as: I should always configure the stimulus range
first, and then calibrate. For example, if I want to get an overall (not
finely granular) sweep of a multiband antenna from 3...30MHz, I would first
select this as stimulus range and then calibrate?

Yes Reset first and then calibrate

If I then want to show a single band, like just 40m or 20m, I would again set those respective
ranges and recalibrate?

If what you are measuring does not have sharp valleys and peaks in SWR then you can just reduce the stimulus range on some NanoVNA's (like the -H and -H4) and the device will interpolate between the calibrated points and give you a fairly good estimate of SWR and Return loss.

But your best option if you are only interested in HF is to calibrate for the entire HF band from 2 to 30 MHz and store that in slot 0. Then calibrate and store your other favorite bands in the remaining slots. That way you can turn it on and be set to go.

Roger