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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.

--

*Dave - W?LEV*


--
Dave - W?LEV

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

On Thu, May 15, 2025 at 11:17 AM, alan victor wrote:

s11 measure in series mode between the channels.

Does this explain the trace gap? I assume that's what you're referring to.

Brian

s11 measure in series mode between the channels.

Those interested in more detail on my last post will find this article informative. The graphs at the end show what should be expected when making measurements of characteristic impedance of coaxial cables.

Nizar,
What I pointed out in my previous post is that your characteristic impedance measurements were not in accordance with well defined transmission theory.

Your results showed a rise in characteristic impedance and then considerable rolloff especially near 100 MHz. What should be observed is a slow decrease which flattens out at VHF. This can be seen in the graphic I posted.

After a few MHz the equation is Zc = SQRT (L/C) where L and C are the inductance and capacitance per unit length respectively. C can be considered constant with frequency while L decreases with frequency. L consists of internal and external inductance. The skin effect and the fact that internal inductance of the inner conductor decrease to zero at high frequencies are the prime reasons for this.

Yes, they can be pretty good for testing at HF if properly chosen and
measured. That's exactly what I do to "quailfy" potentiometers for use at
HF frequencies. It works!

Dave - W?LEV

On Thu, May 15, 2025 at 4:48?PM Team-SIM SIM-Mode via groups.io <sim31_team=
[email protected]> wrote:

Hi Dave

To be Honest , this is graphical results of my used potentiometre
illustrated with NanoVNA attached screenshoots : +j3 Ohm max at 30Mhz

73's Nizar .

--

*Dave - W?LEV*


--
Dave - W?LEV

Hi Dave

To be Honest , this is graphical results of my used potentiometre illustrated with NanoVNA attached screenshoots : +j3 Ohm max at 30Mhz

73's Nizar .