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Colin, which version of macOS and how did you set up the USB ports?
Tried it here with Catalina but some problem finding the device on the USB…

Dana VE3DS

Jerry,

Thank you very much for your recommendations. They are excellent, and I greatly appreciate your taking the time to make them. (Invariably, when I write a blog post I discover I have left something out. So suggestions such as yours are always welcome.)

I should be able to make revisions in a few days, when I’m back in town.

Thanks again, and best regards,

- Jeff, k6jca

On Sat, 19 Oct 2019 at 15:40, Jeff Anderson <jca1955@...> wrote:

On Sat, Oct 19, 2019 at 06:48 AM, Dick wrote:

ps: still trying to figure out a Smith Chart

Dick, some years ago I wrote up some notes on the Smith Chart (basically
describing where those funny curves come from). It might not be what you
are looking for, but if interested, go here:



- Jeff, k6jca

A bit too technical for the beginner I feel. But that’s just the nature of
a Smith Chart.

It is a very long article, which I didn’t look at too carefully, but you
don’t actually state what are the x & y axes of the Smith Chart, nor the
reason it is more practical to plot an *impedance* on a Smite Chart than on
a normal xy graph.

Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

Did you ever figure out how to get the NanoVNA-Web-Client to connect to your Chromebook?

I have not yet tried with the store app; got distracted..

My Samsung Chromebook with either sideloaded apk or web client
also will not connect.

Did you try connecting with Chromebook 'Diginow Serial Terminal' ?
That worked on mine for nanoVNA shell commands..

You might need to run Crouton and install a full copy of Linux.
Full details here:

On 19 October 2019 at 20:23 hwalker <herbwalker2476@...> wrote:


Oristo,
Did you ever figure out how to get the NanoVNA-Web-Client to connect to your Chromebook? My Samsung Chromebook with either sideloaded apk or web client also will not connect.

- Herb

Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032
Amateur Radio G8IFF W8IFF and GMRS WRBV701, e-mail nigel@... www

I keep wondering about the wireless mini keyboards that use a USB "dongle"
that looks like a bluetooth dongle, but isn't.

Bluetooth has profiles, as does USB, so a bluetooth keyboard advertises as HID, instead of SPP,
so would not be recognized as a virtual COM port in Windows.

I researched this a little; of the few systems-on-chip with bluetooth,
I found none with USB host support, so a small e.g. PARTICLE Xenon
or ESP32 board wired to a "Mini USB Host Shield" by spi
would be the cheapest DIY "solution"



There are BC04-B demo boards, which behave like modems (AT commands and all) but USB is not host.

I also bought the AURSINC model from Amazon. It has been great. It is
shielded.
I bought a 3D printed case from ebay. I have no complaints about
anything.

Marco

I bought the one from AURSINC. The price was $73, but it had the input shields, and works fine.

Oristo,
Did you ever figure out how to get the NanoVNA-Web-Client to connect to your Chromebook? My Samsung Chromebook with either sideloaded apk or web client also will not connect.

- Herb

today i returned the non shielded one from Amazon
and see that NooElec was mentioned
they dont show any for sale now

I've just done the MacOS install, went smoothly, all I had to do was adjust
the font size up a bit ;)

Jeff,

The Smith Chart is tricky to explain, your tutorial does a much better job than most that I have seen.

Here's a few adjustments that might be considered, especially if the intended audience changes:


Maybe hammer home the impedance side of the chart before introducing admittance.

As your tutorial notes, there is a one-to-one relationship between a point in the plot of the load impedance and a plot point in the plot of the reflection coefficient. It might help to compare a plot of load impedance with a plot of reflection coefficient for the same data set, and explain how the latter is the more useful representation. I'd say it's more useful because it is bounded to a magnitude of 1.0 for passive devices, with points of primary interest at high resolution near the center of the chart. And that the rather wild curves you get from plotting raw impedance become well behaved circles when plotting the reflection coefficient.

Point out that at a given frequency, the Smith Chart plot is generally just a single point. Since the impedance of inductors and capacitors changes with frequency, a plot for a range of frequencies becomes an oddly shaped track across the Smith Chart, approaching the center of the chart when the impedance of the load approaches the characteristic impedance of 50 ohms.

Probably wise to keep the characteristic impedance at 50 ohms. But could include a brief mention that most Smith Charts will have the characteristic impedance normalized to 1.0 ohms.



Here's a couple interesting addendums to statements made in the tutorial:

Here are plots of Γ in the complex-plane with R held constant (circles) and with X held constant (not circles):

Plots of constant X are arcs of circles. If the magnitude of the reflection coefficient Γ is allowed to exceed 1.0
(as might happen in the case of an amplifier), these arcs can become complete circles.

Note: some authors use ρ in lieu of Γ to represent the Reflection Coefficient.
I believe this is a mistake.
I prefer to represent the Reflection Coefficient with Γ and its magnitude with ρ).

Page 3-1 of Walter Maxwell's book "Reflections III" has the following passages, first published in 1973:

" In combination, the magnitude ratio ρ and phase θ comprise the complex reflection coefficient ρ" (where that final ρ is shown with an overbar to indicate it is complex)

"Prior to the 1950s, ρ (rho), σ (sigma), and sometimes S were used to represent standing-wave ratio. The symbol of choice to represent reflection coefficient during that era was Γ (upper case gamma). However, in 1953 the American Standards Association (now the NTIA) announced in its publication ASA Y10.9- 1953 that ρ was to replace Γ as the standard symbol for reflection coefficient, with SWR to represent standing-wave ratio (for either voltage or current), and VSWR specifically for voltage standingwave ratio. Most of academia responded to the change, but some individuals did not. Consequently, Γ is occasionally seen representing reflection coefficient, but rarely."

From this, we can infer that the preferred manner of representing the reflection coefficient has changed back and forth over the years. It seems Γ is now back in fashion for the complex value, and ρ is now used only for the magnitude of the reflection coefficient.

Reflections III consists in part of a series of QST articles written in the 1970's, it's not organized as a cohesive book, and is not an easy read for the neophyte. Some points remain a bit controversial, but my impression is that Walt had it right. He knew his stuff. Once you get the mechanics of impedance matching and using a Smith Chart down, this book is well worth browsing if you wish to figure out exactly what goes on in a conjugate match.


All that said, you have created an excellent tutorial.
Wish I had access to something like that when first figuring out the Smith Chart.

Jerry


On Sat, Oct 19, 2019 at 07:40 AM, Jeff Anderson wrote:

Dick, some years ago I wrote up some notes on the Smith Chart (basically
describing where those funny curves come from). It might not be what you are
looking for, but if interested, go here:



- Jeff, k6jca

That sure does help, Rune. I was using it on my mobile system and my wifi doesn't reach that far. It would have never occurred to me that Saver needed the internet. Thanks very much. Do you have any idea how fast one has to be to get that screen-capture while Saver is shutting down? Displaying that screen for longer than one millisecond would help. :)

Hello
Ok, great let me try those tips… otherwise it looks real good
Thank you!

73 Dana VE3DS

Hello Dana,
I know that there are a number of users of NanoVNA-Saver on Mac OS X, so it
should run "fine". I don't know if the serial port detection works, but if
you enter the serial port in the field next to the "rescan" button and
click connect, it should connect just fine.

If not, try launching the application with the "-d" command to get
debugging info, and look at the console for what the application is doing
or failing to do. Feel free to send me the where it hangs if it turns out
that's what's happening - I might be able to fix it for the next release.
:-)

Good luck,
--
Rune / 5Q5R

Has anyone compiled this to run on macOS? I did on Catalina, but
it isn’t finding the VNA on the USB port so I suspect there is something wrong with serial.py?
Would appreciate any help or direction on this.
Thanks
Dana VE3DS
Toronto

I would really like to connect my new NanoVNA to my laptop using a wireless connection. It doesn't seem likely that a bluetooth adapter would work at the VNA end, though. I keep wondering about the wireless mini keyboards that use a USB "dongle" that looks like a bluetooth dongle, but isn't. This would have to be two little devices with USB connectors that talk to each other "automatically" and not need any manual intervention like a mouse click to make the connection. Sort of a non-discriminatory bluetooth that would always accept the first connection attempt.

Does anyone on here know of such a device or system? I've been trying with google but I can't seem to come up with the right search terms. And maybe there is some reason why the NanoVNA wouldn't support such a connection anyway. Maybe one of the firmware developers could find a way to add a wireless connection feature to the system. Giving it a fixed, non-routable IP address to use a USB wifi adapter might be a good way.

Thanks for any help or suggestions!

Doug, K8RFT

#59 : UPDATE : [LeastVNA] : version 20191020

Hello,

Allow us, please, to inform you that we just uploaded
the new version of [LeastVNA]:



Instructions:

1. Create a [Shortcut to bbcwdem6.exe]
2. Select a working folder wf, e.g. wf = [K:\LeastVNA20191020]
3. Copy [Shortcut to bbcwdem6.exe] and Paste it into wf
4. Unzip [GLeastVNA20191020.7z] into wf
5. Run [Shortcut to bbcwdem6.exe] to open BBCW IDE
5. Open [GLeastVNA20191020.bbc] within BBCW IDE
6. Put your wf at line :

320 *CHDIR "K:\LeastVNA20191020"

5. Run [GLeastVNA20191020.bbc]
6. Check the created [G-LeastVNA.txt] against the included [Check-G-LeastVNA.txt]
7. If they are identical then you are ready to work with [GLeastVNA20191020.bbc]

8. Build your [f.txt], [s.txt], [l.txt], [o.txt], g.txt] with Putty output from your [NanoVNA]
and run [GLeastVNA20191020.bbc] to produce your [G-LeastVNA.txt]:

#58 : [LeastVNA] ~ [NanoVNA] : Full Final Report 1 : Data and Plots
19 October 2019
/g/nanovna-users/message/5184

Sincerely,

gin&pez@arg

59#

How to connect to NanoVNA

Depending on application, e.g.
if one-port DUT with nominal 450 Ohm impedance,
then SMA cable between balun and CH0,
then SOL cal using 450 ohm resistor for L and wire for S at screw terminals.

If two-port DUT, then 2 baluns needed for THRU "cal"

Hi Rune -

I think you misunderstood my intention in posting that link - it's merely a
good guide which could serve as an inspiration.

It seems good and fairly extensive, but I have not considered
helping describe more PC VNA software than my own and TAPR,
which guide was already written and needs only updating.

It's not my suggested guide
for non-japanese speakers at least - I think the learning curve is a little
steep if you have to learn a new language first ;-)

Translation in Chrome browser seems to work well enough, IMO.
If you suggest some guide in another language, then it goes in the Wiki