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Re: Smith Charts

 

On Tue, Apr 29, 2025 at 09:28 AM, Brian Beezley wrote:


Would a magnification function be helpful?
Analog Instruments (Phillip Smith's firm) sold expanded Smith charts of 3 kinds: expanded about the center with two magnification factors IIRC, and expanded about the high- and low-impedance areas, the latter two for working with open- and short-circuited stubs respectively. They also made admittance charts and charts with negative real part, for parametric amplifiers, oscillators, and the like. I have samples of most of them in a tote somewhere......

I suspect that the expanded-center function would be most useful for the majority of the users; I doubt that anyone is doing graphical solutions of stubs any more..
73, Don N2VGU


Re: Smith Charts

 

Here's what I have at the moment. I can see that two grid colors are important so let me see how much trouble that is.

Brian


Re: Smith Charts

 

Try again...


Re: Smith Charts

 

Here is an example with the display and the captured movement to implement a matching system.


Re: Smith Charts

 

I see. Displaying both grids simultaneously is easy. Do you also need impedance and admittance values
displayed at the same time?
Yes, that is helpful

73
Jeff G8HUL


Re: Smith Charts

 

On Tue, Apr 29, 2025 at 07:05 AM, G8HUL wrote:


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

I see. Displaying both grids simultaneously is easy. Do you also need impedance and admittance values displayed at the same time?

The images show what now happens when you click the mouse wheel.

Brian


Re: Smith Charts

 

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.


Re: Smith Charts

 

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


Re: Smith Charts

 

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


Re: 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


Re: Smith Charts

 

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


Re: Smith Charts

 

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.


Re: Smith Charts

 

Yes on mS.


Re: Smith Charts

 

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.


Re: Smith Charts

 

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

Brian


Re: Smith Charts

 

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


Re: Smith Charts

 

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:

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





Re: NANO APP

 

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


Re: NANO APP

 

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


Re: H4 + nanovna-saver calibration

 

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