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Which VNA. Some early versions on nanoVNA has spikes when switching from fundamental to harmonic mode. The fix was to lower transition frequency. Some other versions could not handle the high frequency limit. The fix was to lower STOP frequency.

Mike N2MS

Ted,
See Msg. #38300. I thot I'd messed mine up trying to upgrade the f/w by the DFU mode, but Stan talked me thru it, and now it works fine.

There's a lot of good help here.

jbl

Permanent installation of the following would go a long ways in protecting
the S11 or source port:

VLM-33W-2W-S+

From Minicircuits. It's presently under re-design, but is available and is
designed to limit large and possibly damaging RF levels on the ports where
it is installed.

Dave - W?LEV

On Fri, May 16, 2025 at 3:26?PM Dragan Milivojevic via groups.io
<d.milivojevic@...> wrote:

Which one? NanoVNA V2 frontend is quite different from H4 (for example).

On Fri, 16 May 2025 at 17:13, Terry Wassell #1398 via groups.io <k3jt.wv=
[email protected]> wrote:

Sad to report that, for the second time, my nanovna is broke from RF over
exposure or ESD. My question is: can I protect the input with some

fuse-

or similar over-load protection device? Yes, I will treat this one with
extra care.
Terry. K3JT

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*Dave - W?LEV*


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Dave - W?LEV

On Fri, May 16, 2025 at 08:30 AM, alan victor wrote:

You should most likely want to add interpolation, say spline.

Alan, I want the program to show what's in a file, not a sanitized version. Note that cubic spline interpolation, the kind of spline I'm familiar with, can yield points well away from a reasonable curve when things go wrong. It's quite tricky to tame. Be on the lookout for artifacts in any plotting program that uses it.

Your S22 curve looks like it has no gap. The S22 data actually does, just like S11. My unsanitized dot plot below reveals it..

I'm think the gap indicates some sort of problem with the VNA. I want to see these things because they call into question the validity of the rest of the data.

Brian

Sorry for the bandwidth.

Brian, two simulators failed to read the Johanson file correctly.
However, a Keysight simulator had no issue. Operated fine.
Here is s11,s22, and 20000 data points and of course the Keysight routine adds interpolation.

You should most likely want to add interpolation, say spline.
GL with the routine.

Which one? NanoVNA V2 frontend is quite different from H4 (for example).

On Fri, 16 May 2025 at 17:13, Terry Wassell #1398 via groups.io <k3jt.wv=
[email protected]> wrote:

Sad to report that, for the second time, my nanovna is broke from RF over
exposure or ESD. My question is: can I protect the input with some fuse-
or similar over-load protection device? Yes, I will treat this one with
extra care.
Terry. K3JT

Terry,

Can you please explain the RF exposure or ESD which caused the failure so
that I can take precautions?

73
Jon, VU2JO

On Fri, May 16, 2025 at 8:43?PM Terry Wassell #1398 via groups.io <k3jt.wv=
[email protected]> wrote:

Sad to report that, for the second time, my nanovna is broke from RF over
exposure or ESD. My question is: can I protect the input with some fuse-
or similar over-load protection device? Yes, I will treat this one with
extra care.
Terry. K3JT

Sad to report that, for the second time, my nanovna is broke from RF over exposure or ESD. My question is: can I protect the input with some fuse- or similar over-load protection device? Yes, I will treat this one with extra care.
Terry. K3JT

Use a different USB controller on your computer and check the USB cable.

On Fri, 16 May 2025 at 16:04, Ted Garrett via groups.io <kq4ymd=
[email protected]> wrote:

It connects, firm ware is the latest for the H model, i fellow the steps
in the guide, the dfu demo software starts as normal starting delete phase,
takes 18 hrs, now im in down load phase and its 4 hrs into it and 6 %.

What firmware do you recommend?

It connects, firm ware is the latest for the H model, i fellow the steps in the guide, the dfu demo software starts as normal starting delete phase, takes 18 hrs, now im in down load phase and its 4 hrs into it and 6 %.

What firmware do you recommend?

Dave,

Good overview. I think it is worth to add a little bit more to point 2 of the recommendations.
Because in case one is measuring a reactive component at a frequency range of interest, which coincidentally is around the self resonant frequency.
Maybe selecting a low frequency range first.

73,
Kees PE0CWK


Op 16-5-2025 om 01:18 schreef W0LEV via groups.io:

Dave

you'll have to swap the Above & Below in the first lines on page 2 ...

73
Luc ON7DQ

Delete phase? There is not normally a separate delete phase in nanova firmware loading. Most of the programming methods have you a) attach to nanovna in dfu update mode, b) Select and outload the new firmware file, and c) restart the nanovna in normal mode with new firmware. The programming software does do a bulk flash erase as the first part of the update process.

It is very hard to truly brick a nanovna.

Which software are you using to update the firmware? Are you able to get that software to connect to nanovna in dfu update mode?

I guess I bricked it. Nanovna H. 3 days of trying to reput the firmware back on it. Can't get it to even delete phase.

Thanks a lot Dave.

Shall go through it and get back to you.

73
Jon, VU2JO

On Fri, May 16, 2025 at 4:49?AM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

I've had several requests on reading the values of inductors and capacitors
using the NANOVNAs. I've put that together in the attachment to this
email. If you want to learn how it's done using the NANOVNA's and the
Smith Chart presentation, the attachment should be of interest to you. For
the write-up, I've used the H4 version of the NANOVNA, but everything
should be applicable to any version of the NANOs or professional VNAs. So,
don't belabor the point that .....waaahhhh....waaahhhh......I don't have
the H4. The technique is applicable to any vector network analyzer.

So, if interested, have a read of the attachment.

Dave - W?LEV


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Dave - W?LEV

Okay! Great! Thank you!

Yahoo Mail: Search, Organize, Conquer

On Thu, May 15, 2025 at 13:35, Team-SIM SIM-Mode via groups.io<sim31_team@...> wrote: Hi Roger

Thanks , I re do the measure of my 25m of RG213 at 100Mhz? (Span 5Mhz ) by this cicle methode see illustration below with graphical renormalized Z0 to center impedances circle around center smith shart.
73's Nizar








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73
Karl
KI4ZUQ

I've had several requests on reading the values of inductors and capacitors
using the NANOVNAs. I've put that together in the attachment to this
email. If you want to learn how it's done using the NANOVNA's and the
Smith Chart presentation, the attachment should be of interest to you. For
the write-up, I've used the H4 version of the NANOVNA, but everything
should be applicable to any version of the NANOs or professional VNAs. So,
don't belabor the point that .....waaahhhh....waaahhhh......I don't have
the H4. The technique is applicable to any vector network analyzer.

So, if interested, have a read of the attachment.

Dave - W?LEV


--
Dave - W?LEV

Please let us know where you are going with this

Simply trying to take the data from the graphic presentation and try to provide an
appropriate explanation and interpretation. The power of any GRAPHIC as opposed to looking '
at a bunch of data is to try to deduce "what does this mean?"

On Thu, May 15, 2025 at 11:44 AM, W0LEV wrote:

Please let us know where you are going with this

Dave, I think Alan is pointing out that I'm using port 1 data for a component measured between the two ports. True, but I'm just using the data to exercise my program, not to draw conclusions about the part.

As long as we're chasing anomalies, here's a good one. It's an MA magnitude/angle file where the VNA botched a point near 180 deg. I'm guessing it was attempting some sort of averaging and wound up with an angle of -1.3 deg when it should be near 180 (or -180). The bad point is in the middle of the data listing.

Brian

Please let us know where you are going with this:

QUOTE: s11 measure in series mode between the channels.

S11 and S22 are reflection measurements.

Dave - W?LEV

On Thu, May 15, 2025 at 6:17?PM alan victor via groups.io <avictor73=
[email protected]> wrote:

s11 measure in series mode between the channels.

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*Dave - W?LEV*


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Dave - W?LEV