Don't know if this is the best place to rant about this, but here goes... Make sure to select DISPLAY->CHANNEL = "S11 (REFL)", not "S21 (THRU)", for measurements like SWR and SMITH charts made on PORT 1 (S11). For HF calibration, use 1 MHz -to- 30 MHz stimulus range: STIMULUS->START = 1 MHz, STIMULUS->STOP = 30 MHz. By all means use a smaller range for higher accuracy if necessary. Always reset calibration data before performing another one: CALIBRATE->RESET. Perform Open-Short-Load calibration and save result: CALIBRATE->OPEN..SHORT..LOAD..DONE->"SAVE 0". All settings and calibration data stored in "SAVE 0" will be loaded upon power-up. Verify good calibration by placing Open-Short-Load devices on PORT 1 and observe that "dot" position appears at right-left-center on SMITH chart center axis. If calibration was done right at the SMA connector on PORT 1 but an open coaxial jumper and/or adaptor is later added, the SMITH chart will show a rotated arc instead of a "dot". By introducing an electrical delay the calibration reference plane can be moved to the end of the jumper/adaptor to compensate. Automatically: MARKER->OPERATIONS->E-DELAY Manually: DISPLAY->SCALE->E-DELAY = "value" (+/- nS or pS) Re-save to include in location of choice, e.g. "SAVE 0", "SAVE 1", etc.
You have descirbed exactly the way that my NanoVNA is acting. It acts like your bad one. R&L is replacing it with a newer version. Your video and testing was immensely helpful! 73
I bought a nano VNA on amazon. I have attempted to build several antennas from quagis to moxons to j poles. My vna always measured poor to mediocre performance. I always assumed I did something wrong, although I measured everything to a T. Now I'm wondering if my vna is faulty all this time. I'm going back to the good old reliable SWR meter.
I've been happy with the aursinc label on Amazon. You could try a second one for something to compare too and return it if it doesn't work as expected. The Nano has so much functionality (when it works), but the cloners have gotten ugly. Amazon link: amzn.to/3ezESBc
My biggest learning with these is that you need to be wary your own interactions and how they impact what you are measuring (capacitive coupling, induction effects etc), how well it is shielded (your Norcal looks hip but it is not shielded) and any grounding effects. The NanoVNA uses a few mW of power to make its measurements/sweeps, it doesn’t take a lot of interference to impact those. To show this, get your good NanoVNA and connect a known good VHF/UHF whip. Find best VSWR and start to interact with it. Point here is that there are so many factors at play that it is going to be difficult to blame the NanoVNA purely. I do agree with the other comments about battery and firmware updates but I don’t believe that any one supplier or manufacturer is intrinsically building dud hardware beyond the odd faulty units.
My NanoVNA H4 is build time Jan 31 2021 Version 1.0.45 and I don't have any issues at all. I have a RIG Expert AA-230 Zoom, AA 650 and a SARK 110. All four give me pretty much the same readings. This is not the firmware version that came with mine. I bought mine from R&L Electronics thinking they did their research before they went out and bought junk. I also purchased the TInySA from them. The TinySA had a slight glitch on the display on 40 meters when I narrowed the span down to 10 khz. I updated the firmware and the little glitch went away. Your video was very interesting and glad you posted it. Barry, KU3X
Usually you are the ground in an HT. But you can add a "tiger tail" and get greater range. When you take the antenna off the HT to test, you need to replace that missing human factor.
@@ronalddang7507 No problem with the simple questions, that's what I'm here for. That's the "tiger tail" I mentioned earlier. Check out this short from my buddy Hayden - Ham Radio DX channel:ru-vid.comccJHdmSE7D4 What are you trying to accomplish? testing the antenna on the nanovna?
I picked up a used Nano VNA F that had some similar issues. Buttons were all out of whack, but calibration was fine. I replaced the lithium battery and now it works like a champion. Problem free. Try replacing the battery, or giving it a reliable supply
Its on the table. I found a really good firmware to install during this diagnostic process. I'm very impressed with how well it gets installed and the "polish" it puts on the device. It just seems like the creator thought about the interface a bit and rounded off the rough edges.
I actually need to buy a NanoVNA and would appreciate your recommendation (link) for which one to buy. By the way, affiliate links are ok with me (because the price doesn't increase for me if I use a link you sponsor, AND I get to support your efforts as well)!
I am missing the red thread in test test procedure - looks more like try and error. Its essential to have proper shielding in place (esp. for higher frequencies) and to have a proper calibration first. When i buy from ebay or ali how can i know what i get? You probably should omit the lowest price offerings ;-)
I am curious as to why the curves werent flatter given the swr was set to 1.0/ division on both devices (later in the video) instead of the 250m/ division you had on your device at the beginning of the video. 1.0/ gives a full range of like 10 vs 250m/ a vertical range of 2. That may not affect the readings or results, but it is curious...
@@temporarilyoffline 1.0 is the default setting. The IMSA guy goes thru that on his 'intro to the nanovna' video - thats the only reason I know that - had no idea what SWR was used for at the time LOL.
I also experienced having to press the screen several times. I think in my case the battery voltage was a bit too low as it seems better now I keep it topped up after every use no matter how short. G4GHB.
I have one a friend gave me ... and I am getting results I would not expect. SWRs in the 10:1 range in the range this dipole is cut for. I'm thinking maybe it's a bad one
This one was a fake, it was also a channel donation and I've kept it hoping that I can fix it someday. I need to do a firmware update on it to use a 3rd party firmware and see if that helps among other things. If your a ham and you're bored... you're doing it wrong!
@@temporarilyoffline all the components in these are relatively cheap to begin with. I would be curious to know if it was truly a fake or if they (Chinese manufacturing) are just buying components in bulk and relying on the law of averages to produce good ones and just accepting that they may have to eat a few returns.
@@bryantwalley This is exactly how I feel about the MMDVM boards - we bought about a dozen of them from Aliexpress and half didn't work - requiring some surgery, etc. Finally I got tired of being QA and just ordered a complete unit from a known brand on amazon. I paid more, but I knew it would work when I got it... and it did.
@@temporarilyoffline I must have skipped over that part, and I must have had good luck with mine for a moment because it started being touchy again (pardon the pun) after I wrote this comment. I’m trying a firmware update tonight and will see if that has any effect. It’s not my nano anyway, so this might just push me towards a non-clone if I can’t get it to cooperate.
I just bought one on Amazon and can return it if it doesn't work right within 30 days. Need it for VHF/UHF antenna testing. I already have an AA-55 zoom for HF.
Great video on how NOT to test if the device is broken or not because you're comparing decimals of SWR against an antenna that only you happen to have. FYI, they sell such things as "RF Demo Kit" VNA test PCBs at 5€ a piece in online stores, which you can actually use to compare against the known reference circuits of the PCB. By the way, you're doing the callibration at the plane of the PCB's output directly, and then you're attaching the antenna using an extension cable, so your callibration is bollocks if you don't add the extra E-Time on the settings to compensate for the increased length of conductor... Please, don't make videos talking about things you really don't know about with certainty, because often you'll end up spreading myths and false ideas. 41k people watched the video and are now left wondering whether they have a faulty NanoVNA without any real evidence from what I've seen that there are brands making copies with false hardware.
Great comment on how NOT to make comments on a youtube video. If you don't understand the concept of the test, don't bother making comments. You'll only end up spreading myths and false ideas. Not many will read your comment, but those that do will probably point out that even the original manufacturer of the NanoVNA indicates there are faulty clones.
@@temporarilyoffline Thanks for not answering to my point about your calibration being faulty since you made it at the plane of the NanoVNA and not of the DUT. As for the clones being "faulty", it's more about a clash between the original makers splitting and one of them remaking the design and selling it to a chinese factory, but the devices they make still work, albeit with more noise than the $300 alternative that the original makers offer...
If you understood the concepts laid out in the video, you'd know that the DUT is the NanoVNA, not the antenna. You'd also understand that even if the viewer didn't have the antenna I have, they could repeat the A/B comparison of the NanoVNA with any antenna, or even a dummy load. Just because you don't have all the facts or understand the concepts laid out in the video doesn't make /me/ wrong.
Why did you keep it? I would have sent it back when the screens would not come up right. Why? It could be a legit unit but broke or it's a crummy clone. Either way, you should have gotten rid of it. It also has a dim display. Not very bright.
By far the number one killer of nano VNAs is static discharge. hams unfamiliar with working with VNAs will foolishly connect their VNA to an outdoor antenna without a pad or without discharging any static on the center conductor and poof goes the front end of your VNA. If you did this in a laboratory with $100,000 VNA you get fired and sued for the cost of the repair. vector Network analyzers are generally considered laboratory grade equipment not field equipment so they almost never have protection against static discharge. It is expected that the user is properly trained in their operation and knows how to discharge any static charge before attempting to connect the DUT. So several mistakes I see in your video, one is you connected an external antenna to lab equipment without properly discharging any static buildup. two you connected lab equipment to an external antenna without an appropriate DC blocking pad You should always use a 3db DC blocking pad on the front end of your VNA. And of course one of the very first things to look for when experiencing erratic performance with microcontroller devices is input voltage. In other words you need to check your battery' voltage as low voltage or inability to supply the required current can cause erratic performance. As a ham radio operator I would expect you to already know this.
Had to send mine back to Amazon, it was doing lots of strange thing. The screen was not operating correctly, lots of retouches on back. Did not agree with either MFJ meters. So I did a screen cal and that made it even worst. So back it went and they gave me full refund to my account. That unit was about $105.00. I may try buying another 🤞 73 Wd4dda
I Have My NanoVna Working Good, But The First Thing I Did I Changed The Basttery So Now It Works 3 Times As Loonger On A Field :) Sorry For You problem, Maybe I Can Figure It Out If I Put My Mind To It, Sadly I Would Have To Have Your VNA To Figure TThe Problem Out, I Bet Its Easy One:)
@@temporarilyoffline Well, You Can Send It To Me And I Can Try To Fix It And Send You Back The VNA, I Have Some Smart Heads Over Here To So I Will Not Be The Only One Figuring Out Your Problem And We Could Maake Videos About This Thing :) I Can Make A Video How I Figured Out The Problem And You Can Make A Video About How Its Changed And Whats Changed And What You Are Doing With It Now And All That Stuff :) Ofcorse You Will Be Allowed To Use My Footage In Your Video Aswell To Show What You Want To Show
@@temporarilyoffline I get that, but after reloading firmware you have to start asking yourself if you're gonna replace components on it or if it's better to just spend $60 on a new one from a different seller. Made for an interesting video anyway.
@@temporarilyoffline you got me hoping the one I just ordered isn't junk. Lol Honestly didn't even cross my mind before the video. Atleast now I'll have an idea of what to look for. Thanks
I realize you don't have the staying power to get to the point in the video where do the exact thing you accuse me of missing... let me make it really easy for you: 14:26
Whats wrong with you. Whats wrong with you. Asked three times, whats wrong with you. Oops missed asking whats wrong with you. Oops missed asking whats wrong with you again. Oops missed asking whats wrong with you again for the third time. Opps, didn't need to ask whats wrong with you, intended to ask something else.
Can it actually be counterfeit? I understand that it is an open source design. My H4 behaves in a similar way. The interface can be unresponsive, and the measurements are not consistent. I think I'm going to buy a V4.
If you have time, or a friend that has a hot air reflow station... You might want to try reflowing that board and cleaning it before updating it again. 👍
