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34 : Trying to Limit the Misunderstanding up to its Removal

Hello,

We feel much obligated to all of you in this thread.

The interested Reader and/or the kind Contributor
is giving us the chance to exercise our duty of
explaining our work to him who is asking specific
clarifications about it.

But in addition to that, he is encouraging, motivating,
and inspiring us to search for a possibly more
appropriate place of our small Objective World
in the big Objective World of Metrology, as it is
Publicly expressed by a bunch of a gradually
increasing number of Organizations - today there
are eight 8 of them - which although they are
activated in obviously very different, widely divergent,
Fields of Knowledge [*], they have, however, as their
Common Cause the International Coordination
of Understanding and Correctly Applying of the
Measuring.

Anyway, by the beginning of this year 2019, this
common effort attracted our interest, because it
sounded in our small world as one of the most
interesting experiments in which we would like
to try to be humbly involved.

Therefore, the dawn of Toy Era in our small world,
as it is signified by the Massive Invasion of the
cheap NanoVnas, it forced us to intensify our
searching in this direction, and thus we started
in the preceding last days - thanks to you all -
a more systematic study of the current edition
VIM3 of the International Vocabulary of Metrology,
which was approved by the voting members of
these very eight 8, in order to see if and where
there is a way for our work to come under the
concepts and terms of this very VIM3 or even
of the previous editions of it.

Sincerely,

gin&pez@arg

[*] International Bureau of Weights and Measures
BIPM, as the coordinator of: (1) International
Electrotechnical Commission IEC, (2) International
Federation of Clinical Chemistry and Laboratory
Medicine IFCC, (3) International Laboratory
Accreditation Cooperation ILAC, (4) International
Organization for Standardization ILAC, (5)
International Union of Pure and Applied Chemistry
IUPAC, (6) International Union of Pure and Applied
Physics IUPAC, and (7) International Organization
of Legal Metrology OIML, plus (8) BIPM itself.

34

On Sat, Oct 5, 2019 at 01:47 PM, DMR wrote:

The file is not corrupted. Move the file to the root of the drive C or D.

No, this is not necessary. It was the corrupt download. Now works.

Hello, I'm developer of NanoVNA Web Client.

I've noticed that the latest Chrome for Android has bugs around WebUSB that prevent the application from successfully getting a USB device.

This motivated me to create and test an Android version that does not rely on WebUSB or WebSerial around serial communication.

It will also be available on the Play Store, but it is still under review and cannot be downloaded from there.

However, the version whose signature is different from the release version can be downloaded as "nightly" from GitHub's Releases page. If you need it, install it and try it out.

The file is not corrupted. Move the file to the root of the drive C or D.

Just a little screen stylus tip (in double sense).

Torbjorn

Hi All,

Well, my initial post certainly raised some 'interest', however I'm not sure that we have actually concluded anything, other than it is problematic :-)

Personally, I think it's worthwhile trying to get these parameters correct, so that bad practice is not further propagated, especially amongst newcomers to VNA's and RF measurements in general, which the Nano VNA is likely to expose them to for perhaps the first time.

Anyway, my thanks to everyone who responded.

Regards,

Martin - G8JNJ

The DMR-CLEAR_MEMORY_DFU.dfu file was corrupt... I have redone the download.
It would be better if there was a checksum txt-file ...

Hi Norbert,
I haven't had time to look at the data yet, as I'm away for an event part
of this weekend, but I just wanted to thank you already for the in-depth
bug report :-)

I will look at it when I get back!
--
Rune / 5Q5R

Hi all,
maybe someone likes to know how I did the SFZ450 filter measurements.
Attached is a picture of the test adapter that can be calibrated with tiny SOL.

73, Norbert, DG1KPN

Why can't I use "DMR-CLEAR_MEMORY_DFU.dfu"

Its only purpose is to erase existing firmware in a device.
A nanoVNA with that firmware installed can >>ONLY<< install firmware.
I downloaded and verified DMR-CLEAR_MEMORY_DFU.dfu
that is linked in

Is there a previous stable version of type "800_aa" (without bugs)?

Previous, probably more stable, maybe some different bugs:

Just my humble opinion, but I think the group needs to start using hashtags. There is a huge amount of great information already in the group posts, wiki and files, but if it can't be easily retrieved, then you get new members asking questions that old members have answered several times. And since the software, firmware and group consensis on important things have changed in just the last few weeks it is difficult to keep current.

Hi Rune,
I did some more testing on the marker issue.
I am using a cal-file with 804 points. The CF=450kHz@10kHz span. If I select one segment it works. Selecting two segments ist doesn't.
Obviously it depends upon span and segment settings.
When I load the cal-file with 101 points, I see the same symptom as above.
Hope that helps!

Kind regards
Norbert, DG1KPN

The 10khz-1.5GHz is not an official build but was done by one of our members
at the request of another member. The newest build was in the message a few
posts back, /g/nanovna-users/message/4073.

That is a tiny font build (not aa).
My smartphone cannot focus well enough for legible text with it.

I would like to try too ...

Thank You and all the best ...

Vlatko

On Sat, Oct 5, 2019 at 07:12 AM, <hugen@...> wrote:

AA version font requires a larger flash, resulting in saving the settings of
the flash address overlaps with the program flash and I will modify the aa
version later.

Is there a previous "stable" version of type "800_aa" ("without bugs")?
I am glad that you will continue with the modification of the 800_AA version. Thank's for your job.

Why can't I use "DMR-CLEAR_MEMORY_DFU.dfu"?
Thanks

Hi Bryan,

I was able to duplicate your measurement, also with a 68 pF capacitor.
On this screenshot, it's easy to see the effects of frequency on this capacitor, and what you should watch out for.

While profiling (and learning) the NanoVNA myself, I'm coming to the realization that this is a pretty good component tester.

There are limits to resistor values, the precision gets increasingly lower when you go above 1K Ohm, but is great for lower value resistors (<100Ohm) due to the 50 Ohm bridge and calibration point.
For inductors and capacitors the Nano is performing very well, IF you keep an eye on the Smith chart and the (R+jx) factor. You may have to adjust the maximum frequency to stay in the proper half of the chart, as I stumbled on in my first attempts. ("trap for young players")

Enjoy!

I don't know the exact numbers but the cost target is certainly not 100 USD, especially if the target retail price is under $60 ;)

To get some idea the LCD costs on the order of $4, and the MCU $1.5. Any cost increase over $1 requires extensive justification and (most likely) shaving costs elsewhere. A bigger display compounds the cost increase because the PCB also has to be bigger (+$3), the MCU has to be in a bigger package (+$1.5), and of course the LCD itself is a bit more expensive (+$2). In total that is $7.5 of additions which realistically means +$22.5 in retail price, which make a huge difference in competitiveness of the product. To get an idea compare the sell volume of the NanoVNA-H (4000 units/month) to the NanoVNA-F (100 units/month).

Hello

Re LCD size.

What if e.g. a RPi4 is used as the digital board? I understand that the component cost target is 100 USD. A single RPi is 35 USD so in volume it is probably cheaper. The ADC would have to be on the RF board then, but the RPi would cater for more displays options I think. Another added benefit is the modular design.

For stand alone lab use a display larger than 3,5" would be really nice.

Bo

Hi

During alignment or design iterations of a filter seeing the 1 dB, 3 dB, 6 dB and "many" dB points are quite handy.

Bo

1) I installed the NanoVNA-H__800_ch_20191003 version and now it no longer crashes (after the screen calibration, with or without saving).
With 4 tracks the fonts are now very small ... this is a problem for me.

2) In session "Upgrade or Verify Action", the program does not allow me to load the file DMR-CLEAR_MEMORY_DFU.dfu ... Response: "This file doesn't have a correct format..."
Why?