NanoVNA top lines documentation?



Is there a link to anything (PDF, YouTube, etc) that covers what the top lines on the NanoVNA can report and how to interpret them (I have the H4)? I know there's a lot that can go on up there... I've searched the forum but not found any comprehensive reference.. thanks...



The Wiki to this site should answer your questions.

Dave - WØLEV

On Thu, Oct 10, 2024 at 4:10 PM Matthew Rapaport via groups.io <quineatal=
gmail.com@groups.io> wrote:

Is there a link to anything (PDF, YouTube, etc) that covers what the top
lines on the NanoVNA can report and how to interpret them (I have the H4)?
I know there's a lot that can go on up there... I've searched the forum but
not found any comprehensive reference.. thanks...





--

*Dave - WØLEV*


--
Dave - WØLEV



Hi Dave... One could only hope. But I've been there and it's not even close! I suspect I'm asking for the moon...



No, you're not asking for the moon.

Each trace represents one individual measurement of the VNA over the
requested frequency range and parameters specified. Yea, that doesn't help
you much?

I'll turn on mine and go down each line as mine presents on the touch
screen. I'll use the H4, but others are similar, if not identical.
Oops..... I've got mine set to display only the most useful of
measurements, the Smith Chart. Dig for another model. Let's go with the
Lite VNA 64:

Each colored line is linked to the identical color of the data located at
the very top of the touch display. The data at the top is not only linked
color-to-color of the each line, but also the position of the cursor
placement on each respective line.

On my Lite VNA 64:

Top Yellow: represents the log magnitude of S11

Next Green: represents the complex impedance of S11 at the cursor
position as read on the Smith Chart. This is represented in either R ± jX
or R and the reactive component value. That preference can be chosen by
the user elsewhere in the operation tree.

Next down Light Blue: represents the log magnitude of S21, the throughput
measurement of the network (gain/loss response of the network be it active
or passive).

Last Lavender or violet: Represents the phase of S11.

Finally, if a cursor is choses and in the printed data at the top, the
frequency of the cursor is noted in white.

In all measurements where the dB is invoked, the default is 10 dB per
division.

MODERATOR (Dave D): If not already present, could you please place this in
the Wiki.

Dave - WØLEV

On Thu, Oct 10, 2024 at 4:26 PM Matthew Rapaport via groups.io <quineatal=
gmail.com@groups.io> wrote:

Hi Dave... One could only hope. But I've been there and it's not even
close! I suspect I'm asking for the moon...





--

*Dave - WØLEV*


--
Dave - WØLEV

1 Людина сподобалось це


Matthew,
Have a look in the group's files area: https://groups.io/g/nanovna-users/files
There is the original user manual I translated from Japanese to English(now about 30% out of date) it will get you going:
https://groups.io/g/nanovna-users/files/NanoVNA-User-Guide-English-reformat-Jan-15-20.pdf
There is a document I wrote on the serial port commands: https://groups.io/g/nanovna-users/files/NanoVNA_Console_Commands_Dec%209-19.pdf
There are videos by Barry K3EUI on YouTube - Lots!
There is the absolute beginner's guide:
https://groups.io/g/nanovna-users/files/Absolute%20Beginner%20Guide%20to%20The%20NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_5.pdf
Finally, use the search command for the forum (and internet) - there is a document at the very beginning of the WIKI on efficient use of that feature and how to drill down to find what you're looking for.

But, above all, grab a length of coax, some coils and caps and PLAY with your new piece of gear!

Note: it's NOT a power meter and you'll fry the inputs if you try to measure live. Keep inputs below 10dBm.
Cheers,
Larry

1 Людина сподобалось це


Dave and Larry, thanks. Larry I will explore those links. To both of you I have been using the VNA for a while. and watched LOTS of videos. Here's a specific question related to screen shot attached. It's this sort of documentation I'm seeking... Sorry if it does not come out rotated correctly, but I think you will get it...

Trace(0) is resistance (S11 test on a HT antenna). On the upper left it says 453.2 ohms (no ohm symbol on my keyboard). That makes sense as the marker on the blue Smith Chart line (trace(1)) is way over to the right side of the graph—I’ve seen that resistance value report in “k ohms” also.

Now look at the Smith numbers: 803m-j19.3m. Ignore the imaginary value. The blue marker is as close to the 0 reactance line as I can get it, but it’s close enough. But what about the “real” value? How do I interpret it? The “m” can’t mean milli-ohms because even if that’s normalized to a 50 ohm center the true value would be 0.803 x 50 = 40.15 ohms an impossible value on that side of the chart. If the number was normalized and 8030m that would come out to 401 ohms much closer to the report on the upper left. To match 453.2 ohms, it should be 9064m. Could this be just a bug in my firmware level? If it’s not a bug, what does that real value mean?

Matthew KD6KVH



Matthew, you have your Smith chart set to display the "Re + Im" data, which is the complex reflection coefficient (i.e. raw S11 measurement data). Its real value goes from -1 on the left of the Smith Chart to +1 on the right hand side. So the 803m is indeed 0.803 as you would expect. You can't just normalize that number to 50, you have to convert it to an impedance first: but the nanovna does all of that for you.
You can change the settings for the Smith Chart to read what you are expecting "R +jX", or one of several other formats. Select Display -> Trace and make sure the blue trace is selected. Then select Display -> Format S11 (Refl) and you will see that "Smith" is checked, and has "Re + Im" below it. Select that item and it will bring up your options to change it.
Do some more exploring in the Display -> Format menus, there are tons of options. Just remember that they are effective on the currently selected trace. And once you get your traces set the way you want them, you can do a calibration save and they will all be set next time you recall that save (or if you choose to save to slot 0 it is set on power-on).
Stan



Stan you're a genius! I had NO IDEA one could hit SMITH twice to bring up those other computations! That's what I was missing here! Thank you very much! 👏👏🙏



Matthew,

If you follow Stan's procedure, could you please redisplay your original setup so we can compare the shots? I'd appreciate it, thanks.

Mike C. Sand Mtn GA

On 10/11/2024 12:23 PM, Stan Dye wrote:
Matthew, you have your Smith chart set to display the "Re + Im" data, which is the complex reflection coefficient (i.e. raw S11 measurement data). Its real value goes from -1 on the left of the Smith Chart to +1 on the right hand side. So the 803m is indeed 0.803 as you would expect. You can't just normalize that number to 50, you have to convert it to an impedance first: but the nanovna does all of that for you.
You can change the settings for the Smith Chart to read what you are expecting "R +jX", or one of several other formats. Select Display -> Trace and make sure the blue trace is selected. Then select Display -> Format S11 (Refl) and you will see that "Smith" is checked, and has "Re + Im" below it. Select that item and it will bring up your options to change it.
Do some more exploring in the Display -> Format menus, there are tons of options. Just remember that they are effective on the currently selected trace. And once you get your traces set the way you want them, you can do a calibration save and they will all be set next time you recall that save (or if you choose to save to slot 0 it is set on power-on).
Stan

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Hi Mike... I will do that tonight and post, but the only thing that should change are the numbers displayed on the upper right of the screen..



Ok Mike... 2 pictures... 1 with R+/-jx and 1 with G+/-jx shows you an admittance chart! Same antenna as yesterday...

1 Людина сподобалось це


For me, every little bit helps, thanks.

Mike C. Sand Mtn GA

On 10/11/2024 7:07 PM, Matthew Rapaport wrote:
Hi Mike... I will do that tonight and post, but the only thing that should change are the numbers displayed on the upper right of the screen..