NanoVNA calibration shows marked items.  - Page 1
Forum section: electronics / testgear

author: MBY
author_rank: Regular Contributor
timestamp: June 03, 2020, 12:48:37 pm
content: (Wasn't there a big NanoVNA-thread? I cannot find a "master thread" when searching for "NanoVNA")My NanoVNA is acting up weird and I don't seem to be able to calibrate it correctly. When I go to the menu again just after a calibration, the "load" cal point is marked. I usually just do a open-short-load-cal, but I've tested with a full calibration and then both "load" and "isoln" shows marked, see attached picture.I have not found any mention on this in the various user guides. If I do a cal reset, the markings sometimes disappear but show up again after a calibration. My left hand column says C0 D R S T X, which I interpret as calibration indicators.What does those markings mean? And also, the "correction" menu alternative, what does that do?

author: aristarchus
author_rank: Regular Contributor
timestamp: June 03, 2020, 04:47:23 pm
content: https://groups.io/g/nanovna-users/wiki

author: MBY
author_rank: Regular Contributor
timestamp: June 03, 2020, 08:31:46 pm
content: Quote from: aristarchus on June 03, 2020, 04:47:23 pmSorry, but that link goes to some sort of login-page. Is there information behind a paywall?

author: aristarchus
author_rank: Regular Contributor
timestamp: June 03, 2020, 09:49:05 pm
content: The nanovna-users group is a free non-pay group.The link gives you access to all the information about the various nanoVNA versions and their user manuals, schematics, githubs, calibration procedures, use cases and PC software to use with.You can also find similar information scattered around in the various github repositories of the nanoVNA versions if you search with google, though the link tries to keep all of them gathered.BTW you did not mentioned what exactly type of nanoVNA you got, there are quite a few nowadays, in the link provided there is information for almost all nanoVNA versions existing.

author: MBY
author_rank: Regular Contributor
timestamp: June 03, 2020, 11:03:43 pm
content: Quote from: aristarchus on June 03, 2020, 09:49:05 pmOkay, will try to check it out even if I don't like to sign up to things. I don't know really what version I have, it's black and quite recent. The firmware didn't say anything about the version, but after an update it shows "NanoVNA-Q", Kernel 4.0.0, version 0.4.4-e679893-release. But those thing are firmware of course.

author: hugo
author_rank: Regular Contributor
timestamp: June 03, 2020, 11:53:08 pm
content: QuoteAre you talking about this one:https://www.eevblog.com/forum/chat/why-do-so-many-people-here-go-nuts-over-garbage-gear-from-china/https://hexandflex.com/2019/08/31/getting-started-with-the-nanovna-part-1/

author: joeqsmith
author_rank: Super Contributor
timestamp: June 04, 2020, 01:42:21 am
content: There was this one as well along with a few other smaller ones:https://www.eevblog.com/forum/rf-microwave/nanovna-custom-software/Easy just to use the search. NanoVNA should get you there.I am running some flavor of radiolistener's firmware still and it may not behave the same as yours. As far as I knew the Correction was just an easy way to toggle the correction factors on and off.You can find the left hand column indicators in manual for it. The one I am looking at it 2019-08-07_NanoVNA_v02.pdf. Page 6 seems like what you are looking for.

author: MBY
author_rank: Regular Contributor
timestamp: June 04, 2020, 02:15:58 am
content: Quote from: joeqsmith on June 04, 2020, 01:42:21 amYou mean likehttps://metalab.at/wiki/images/8/8f/2019-08-07_NanoVNA_v02.pdf? Page six there is only a schematic for the menu system and tells what the annunciators/letter icons at the left means. No mention of any troubleshooting and my annunciators do not indicate any errors. My calibrations is "all over the place" with the logmag and smith jumping around like crazy even when I leave it open or connect a dummy load. And, as I said, if I enter the cal menu again, the "load" is marked for some reason. If I do a full cal, the "isoln" also is marked It is almost as the device wants to take a new cal point from the dummy load. And, after a calibration the smith chart doesn't show 50 ohms for load, or sometimes shows 50 ohms for both open and load in the smith chart. This behavior started after I tried to calibrate it with a 2 meter SMA cable instead of direct on the port, as I wanted to compensate for the coax.(And the "correct" button did not change state or indicated anything, so the manual and descriptions didn't make any sense. But after upgrading FW, one can now mark and unmark the "correction" button and that makes much more sense, *but* it is worse when "correction" is marked).My main question is why "load" is marked as if one were in the middle of a calibration, when you go back to that menu. It seems like the device is trying to tell me somethings wrong with the calibration (and indeed it is) but I can't find any mentions of these issues and things like "NanoVNA calibration marked item" is, of course, "ungoogleble". I've seen many fine manual and guides for the NanoVNA and I was very pleased with it until it decided to stop accepting calibrations. I've tested with different loads and shorts than those provided with the unit.I hope this wall of text makes any sense. I'm a bit to tired to be fully coherent...

author: joeqsmith
author_rank: Super Contributor
timestamp: June 04, 2020, 03:45:31 am
content: You had posted " My left hand column says C0 D R S T X, which I interpret as calibration indicators." and I merely pointed out where this was documented. It was not intended to solve your other problems.I would have no way of knowing what condition your cables, standards or VNA are in, or what version of firmware you have installed. The fact you claim it all worked and then broke when you ran a cal, leads me to believe something was damaged. Of course, now that it's been reflashed you have added more variables.I pretty much have kept the same set of cables attached to it and will torque them. So far, it's held up fine. I basically run it headless so I won't be much help as I don't pay much attention to the Nano's screen. That and as I mentioned, running I would guess an uncommon version of firmware.If you have SMA adapters, you could start to test the cables and standards with a meter. If it's the VNA, I wouldn't waste too much time on it. At $50, it's disposable.

author: MBY
author_rank: Regular Contributor
timestamp: June 04, 2020, 03:21:01 pm
content: Yes, thank you for your answer! I too have no way of knowing the stock firmware, but I flashed it with NanoVNA-Q-0.4.4-e679893. I've checked the cables and now I'm only experimenting with calibration without cables. It DO function sometimes, but the puzzling bit is just the markings in the cal menu. That means, as I interpret it, as the software is aware that something is wrong, so I just wonder if someone can figure it out. It is possible that the VNA is damaged of course. How do yours cal menu look if you just enter it, without resetting and without actually calibrating? Maybe I hunting ghosts and it supposed to look like in my attached picture.

author: aristarchus
author_rank: Regular Contributor
timestamp: June 05, 2020, 12:07:02 pm
content: A ggod starting point would be to first let us know clearly which exactly nanoVNA version you have.A complete photo or something eg a buy link.

author: MBY
author_rank: Regular Contributor
timestamp: June 12, 2020, 12:51:56 am
content: Ah, yes. When staring this thread, I wasn't aware that there were many versions, clones and clones of clones. Here is the buy link:https://www.banggood.com/Original-NanoVNA-Vector-Network-Analyzer-50KHz-900MHz-Digital-Display-Touch-Screen-Shortwave-MF-HF-VHF-UHF-p-1471576.html?rmmds=myorder&cur_warehouse=CNSome pictures of the internals in reviews and such below in the link.My unit seems to work now, btw, but the markings is still buggering me and I really want to know what they mean (I'm talking of the pictures I posted in TP, not the annunciations described in manuals and guides).

author: aristarchus
author_rank: Regular Contributor
timestamp: June 12, 2020, 10:00:15 am
content: Hi,It looks to me that there is a good chance that you loaded the wrong firmware in your nanoVNA.As it is shown in the nanoVNA-Q repository, down in the comments of the page here->https://github.com/qrp73/NanoVNA-Q"NanoVNA-Q is based on @edy555 code, includes improvements from @hugen79 and is targeted for NanoVNA-H hardware."From what I understand you got the early non-H nanoVNA, thus I guess there has to be some issue there.What I advise you is to go in the nanovna-users group mentioned earlier, let them know what is your vna version and ask them what is the latest/best firmware to flash.

author: MBY
author_rank: Regular Contributor
timestamp: June 12, 2020, 10:17:59 pm
content: Quote from: aristarchus on June 12, 2020, 10:00:15 amAh, yes. That's quite possible. But the "marked items" were there even with the stock FW and apart from that, the unit seems to work with the new FW (but I guess I should not trust the new 1500 MHz range with a pointy stick).I probably have to do as you say, to register on that site. I don't know if there is something wrong at all, but it annoys me.