nano vna - Page 1
Forum section: electronics / rf-microwave

author: m3vuv
author_rank: Super Contributor
timestamp: November 14, 2019, 01:19:12 am
content: Hi all,ive been looking at getting a nano vna from ebay,ive a few questions,is there models to avoid?,are they any good for antenna measurments,and how do they compair to say an mfj analyser?,i currently use a fox tango aa-14 aa,its handy with bluetooth and the android app,will a nano vna give me a lot more info about antennas?,thanks in advance,lastly would you recomend buying one?,i was looking at this:https://www.ebay.co.uk/itm/NanoVNA-H-HF-VHF-UHF-Vector-Network-Analyzer-Antenna-Analyzer-50K-1-5GHz-Case/254413699311?hash=item3b3c3cf8ef:g:wf4AAOSwJYVdw7g~

author: radiolistener
author_rank: Super Contributor
timestamp: November 14, 2019, 04:22:42 am
content: they are better than mfj analyzer. works ok. But screen size is small.

author: bob91343
author_rank: Super Contributor
timestamp: November 14, 2019, 05:31:23 am
content: The nanoVNA is a terrific bargain. It does nearly everything a ham would need. Measures antennas, impedance, SWR, and so on. You can determine coax characteristic impedance. Measure capacitors, inductors, resistors. Spectrum analysis. Line length and loss. Bandwidth. Plots Smith charts. It's a sweep and cw signal generator, very accurate frequency.If you don't like the screen size, use the PC software and you can see everything on the computer screen.As you may have figured out by now, I like mine. While of course it has limitations, they aren't very significant for most ham radio purposes. If you build antennas, this is a must have.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 14, 2019, 05:51:33 am
content: Andreas Spiess has a vidjeo comparing that with another one.

author: OwO
author_rank: Super Contributor
timestamp: November 14, 2019, 06:02:50 am
content: Take what I say with a grain of salt because I'm on the NanoVNA V2 design team, but the original NanoVNA (everything you can find on ebay/aliexpress right now) has severe accuracy problems above 300MHz:https://groups.io/g/nanovna-users/message/6484What happens is that in harmonic mode the DUT's response to the fundamental frequency bleeds in, and what you are measuring isn't the impedance at the frequency shown, with S11 errors of 3dB in the above plots. It will show perfect calibration but show you wrong impedances once you measure something other than the cal kit.

author: vinlove
author_rank: Frequent Contributor
timestamp: November 14, 2019, 12:21:36 pm
content: If your usage is up to 300 Mhz, then it is still fine machine to have?But the impedance reading problem sounds critical, does it affect the whole freq. whole spectrum? or is it problem of above 300 Mhz thing?Have they resolved the problem now? The new ones on sale now is OK? Or are they selling the original version with the problem?

author: bd139
author_rank: Super Contributor
timestamp: November 14, 2019, 12:32:12 pm
content: Definitely buy one. Awesome bit of kit. I bought one from this ebay seller. Was a good clone i.e. has battery and shielding and all cables included:https://www.ebay.co.uk/itm/323899986991Is drop shipped to UK. Takes ~5 working days to turn up.I've used one for measuring filters:And setting up my 40m dipole:Good to 300MHz. I won't try it higher as the harmonics thing is a shit hack.As it comes (I printed a case for it):Screen is tiny but you can connect it to your PC with a USB cable and use NanoVNA-saver to do all the stuff you need.I'm awaiting a big fat power attentuator at the moment and will use it for PA gain measurement as well etc. I've used it to design input matching networks for the PA already.Edit: just in case I haven't been clear enough it's awesome. I've had MFJ and RigExpert impedance analysers and this is so much better, will quite happily work up to 2m band easy and is 1/10th of the cost.

author: radiolistener
author_rank: Super Contributor
timestamp: November 14, 2019, 01:25:41 pm
content: Quote from: vinlove on November 14, 2019, 12:21:36 pmthere is no impedance problem at 300 MHz

author: Grandchuck
author_rank: Super Contributor
timestamp: November 14, 2019, 06:13:28 pm
content: Below 300 MHz, the accuracy is very good. There is an example below.

author: profdc9
author_rank: Frequent Contributor
timestamp: November 15, 2019, 01:02:52 am
content: You might want to check out the VNA I'm working on. It tries to combine the best of the EU1KY and NanoVNA, achieving the performance of the EU1KY at above 300 MHz which the two ports and lower cost of the NanoVNA. It is athttp://www.github.com/profdc9/VNAIt uses the EU1KY bridge which I think is somewhat better suited to higher frequencies and impedances.

author: OwO
author_rank: Super Contributor
timestamp: November 15, 2019, 04:31:11 am
content: I don't think that's due to the bridge topology though; the nanoVNA bridge is hampered by not having a balun and relying on the common mode rejection of the sa612 mixers, which isn't good at high frequencies. Simply adding a stage of balun will give you 30dB directivity to 300MHz and two stages of baluns plus nulling can get you 20dB directivity to >2GHz. Doesn't matter how you rearrange it a bridge circuit requires one of the ports to be floating or differential. On the NanoVNA it's the coupled port, and on your design it's on the output port.I experimented with various bridge topologies a while ago and found it was impossible to get good port 1 matching up to 3GHz with any off the shelf balun if the balun is on the output port. I will be testing a new topology with a differential *input* port instead that will allow a balun-less bridge if you have a differential RF source (like the adf4350).

author: vinlove
author_rank: Frequent Contributor
timestamp: November 15, 2019, 10:12:43 am
content: It looks great. I placed an order for one. It should be here on early next week.

author: edigi
author_rank: Regular Contributor
timestamp: November 16, 2019, 10:50:30 am
content: Quote from: bob91343 on November 14, 2019, 05:31:23 amThat's not. It has roughly 101 10kHz wide windows that works perfect if you set around 1MHz span. In case of lower span those windows overlap and you don't get any better resolution and with higher span there will be gaps, the whole things becomes like a comb filter (using more point from PC may help but can become very slow). That means that you can easily miss a signal although its there. So maybe its OK for very rudimentary spectral analyses if you know its limitations but its better not to think about it as something that can be used for spectrum analyzes.Generally it can have issues (my, just like most, has) above 25-260 MHz if the temperature is too high or if its too low (a recently developed feature of mine that after cold start around 1 min there are zig-zags) of if battery becomes low.The push-able rotating button becomes sticky quite quickly and needs rotation from the edge.The LCD is also rather small.All in all its a good thing and it definitely worth its price but one has to learn accepting its limitations.There is also a bigger display version NanoVNA-F that is also probably better worked out, however bigger, heavier and pricier as well. As the operational principle is the same, most limitations apply there as well.Quote from: OwO on November 14, 2019, 06:02:50 amWhile this direction is more pronounced due to the stronger fundamental, the opposite can also cause surprises. Thus the clock signal is a good idea to keep it simple but I look forward to the next version that you are in and hope clean spectral signal will be used there.

author: Qmavam
author_rank: Regular Contributor
timestamp: November 18, 2019, 02:32:45 am
content: I don't have much understanding on this, but I did see a larger version that says 1000MHz.NanoVNA-F 4.3" LCD Display 50KHz-1000MHz HF VHF UHF VNA Vector Network Analyzerhttps://tinyurl.com/wgkfrjlOr !https://www.ebay.com/i/283622570322?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=283622570322&targetid=541454015412&device=c&mktype=pla&googleloc=9011614&poi=&campaignid=6470549460&mkgroupid=81274343007&rlsatarget=pla-541454015412&abcId=1139336&merchantid=118842334&gclid=CjwKCAiA_MPuBRB5EiwAHTTvMT1sfDKMXSPs_mLBKM7HifL_uQtiZi0U3Nz-UlGtM-haU75-bPVTURoChPMQAvD_BwE

author: vinlove
author_rank: Frequent Contributor
timestamp: November 18, 2019, 05:06:08 pm
content: deleted double message

author: vinlove
author_rank: Frequent Contributor
timestamp: November 18, 2019, 05:06:47 pm
content: nanoVna arrived, but there is no patch cables included. Just 3x SMA end male terminators and USB cable.Not a good deal this was. Having to get the patch cables or adaptors separately means extra cost and added delays.

author: vinlove
author_rank: Frequent Contributor
timestamp: November 19, 2019, 11:19:49 am
content: Had to order 2x sma patch cables for the nanoVNA.Should have checked the nanoVNA pack included the sma patch cables.But it looks promising, and I will be watching some youtube vids for the tutorials.

author: vinlove
author_rank: Frequent Contributor
timestamp: November 21, 2019, 10:00:59 pm
content: Get one with SMA cables, so you don't have to buy them separately unless you already have the cables.I just got mine, and the sma cables arrived as well. I did a quick run of checking my 2m and 70cm mobile antenna, and the SWR was 1:1.4 on 2m, and 1:1.1 on 70cm.My Baofeng UV5R rubber duck antenna was 1:1.6 on 144 Mhz, but 1:18.1 at 430 Mhz. The Baofeng UV5R rubber duck antenna is no good, and unusable on 430Mhz.I only just found out about these antennas thanks to the nanoVNA.I ordered more patch leads for sma to PL259, so I could check my HF antennas. This is great cool stuff.I am sure there are tons of other stuff this thing can do, but it took me 2 minutes to find out how to sweep and check SWR of antennas, and that is good enough useful for me for now.

author: Electro Fan
author_rank: Super Contributor
timestamp: November 26, 2019, 05:16:58 am
content: Seems to be discussion of variants...https://groups.io/g/nanovna-users/topic/60206197?p=Created,,,20,2,0,0::recentpostdate%2Fsticky,,,20,2,0,60206197

author: m3vuv
author_rank: Super Contributor
timestamp: November 26, 2019, 07:22:57 am
content: Any idea where to get the pc s/w for this?,looks like its not included from epay!

author: m3vuv
author_rank: Super Contributor
timestamp: November 26, 2019, 07:31:25 am
content: Just wondered if its possible to retro fit a 4.3 inch display to one of these,anyone tried doing it?

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 26, 2019, 08:01:43 am
content: Quote from: m3vuv on November 26, 2019, 07:22:57 amThis is a nice one:https://github.com/mihtjel/nanovna-saver/releases/tag/v0.2.0

author: bob91343
author_rank: Super Contributor
timestamp: November 27, 2019, 06:57:58 am
content: I played some more and found I could operate it up to 1.5 GHz. It easily measures line length. If you can measure the physical length then you can compute the velocity factor. And measure characteristic impedance.I measured resonance and Q of an LC circuit. I haven't tried a crystal yet but frankly I don't care about that.I could agonize over the limitations but they certainly aren't important most of the time. And I have other devices that can overcome its limitations.One thing I didn't expect is that it's a marvelous learning tool. I can fool with terminations and line lengths and see how everything depends on which factors. Coax attenuation is easy to measure as well. Resistor properties vs frequency.I can't say enough good about this device. And after a bit of fussing, it becomes very user friendly. Its accuracy blows my mind. I built a little load from a half dozen 82 Ohm resistors and should have gotten 54.7 Ohms. I measured almost exactly that both with my expensive bench gear and the nano, I checked a few capacitors and inductors and once again found very good agreement with high class gear.

author: m3vuv
author_rank: Super Contributor
timestamp: November 30, 2019, 09:30:20 am
content: Quote from: radiolistener on November 14, 2019, 01:25:41 pmwell i ordered one from the link as recomended,got a tracking number,turns out it was a false number,seller marked it as posted but royal mail hadnt even received the vna,that was 3 days after seller said it was posted!!,,turns out its from china!,seller hasnt replied to my mails so trying to get my money back via ebay,seems a lot of recomendations are bogus!!

author: bd139
author_rank: Super Contributor
timestamp: November 30, 2019, 09:50:25 am
content: That’s normal. Just wait - it is drop shipped. They print the label and then don’t send it until it arrives bulk from China. Mine took 5 days to turn up (working days). It was delivered from UK not China.You could pay £300+ for a one port RigExpert from ML&S instead and get the red carpet

author: radiolistener
author_rank: Super Contributor
timestamp: November 30, 2019, 02:38:21 pm
content: Quote from: m3vuv on November 30, 2019, 09:30:20 amoriginal NanoVNA-H is from China. If you bought it from other source you're at risk. There are also a lot of clones of NanoVNA. Some of them may have bad perofomance and some may be defective.In order to protect your money I recommend to buy on aliexpress. If you won't receive item or get defective item, you can open dispute and return your money. It works safe for buyer.

author: m3vuv
author_rank: Super Contributor
timestamp: November 30, 2019, 09:18:24 pm
content: I spoke too soon,it was delivered about 15 mins after my post!,seems ok except the thunbwheel thing its total garbage,that seems normal tho i take it now just need the windows s/w for it the nanovna saver ver 0. 2.0 exe is crap,the screen image jitters all over the place and is unusable,anyone know of a decent one?,the vna has 0.2.3-2-g8ac9166 firmware,my pc is running win7 64 bit sp1,cheers.

author: bd139
author_rank: Super Contributor
timestamp: November 30, 2019, 09:23:26 pm
content: Yeah I don’t use the thumb wheel on mine. You can poke the display with a bic lid where you want to dump the cursor.

author: radiolistener
author_rank: Super Contributor
timestamp: November 30, 2019, 09:31:38 pm
content: Quote from: m3vuv on November 30, 2019, 09:18:24 pmyeah, my NanoVNA also has terrible thumbwheel. It has false triggering.

author: m3vuv
author_rank: Super Contributor
timestamp: December 01, 2019, 12:45:33 am
content: my thumbwheel flexes big time,i m going to superglue a support ie spacer/shim from the top board to the center of the thumbwheel,should cure it!

author: bob91343
author_rank: Super Contributor
timestamp: December 01, 2019, 04:29:52 am
content: I just use an old drafting pencil made of metal. The 'wrong' end is a perfect stylus and I can do anything I want.I have said it before but will repeat that the nano is fantastic. It does it all, and so cheap and portable. I have stocked up on SMA cables and adapters so now I can do anything. I do anticipate failure of the connectors but new ones are easy to install. Power switches are very cheap, like only a few cents each. This is finally something done right, and I love mine (obviously).I don't connect mine to the computer although I did try that for a while. Sometimes the small display is a bit hard to read but I keep a magnifier handy. I would guess that in direct sunlight it wouldn't be very good.It measures L, C, and R, and propagation delay and characteristic impedance and SWR and line length and coax attenuation. I got my money's worth in the first hour and it keeps surprising me. And there are some menu options I haven't tried yet.

author: m3vuv
author_rank: Super Contributor
timestamp: December 02, 2019, 03:40:06 am
content: is there any advantage of upgrading the firmware on these ?

author: bd139
author_rank: Super Contributor
timestamp: December 02, 2019, 08:07:36 am
content: I have a personal approach that if it’s an embedded system and not network connected then don’t touch it if it works. Has done me well over the years

author: erikka
author_rank: Regular Contributor
timestamp: December 02, 2019, 08:09:00 am
content: Depends on what firmware you have now.Here you can find a comparison tablehttps://groups.io/g/nanovna-users/message/7477

author: m3vuv
author_rank: Super Contributor
timestamp: December 02, 2019, 09:58:22 am
content: my firmware version is: 0.2.3-2-g8ac9166i cant find it on the chart/list.

author: m3vuv
author_rank: Super Contributor
timestamp: December 03, 2019, 11:02:41 am
content: Well,ive been trying to load the hugens firmware on to the vna,it only has 2 traces but bigger fonts,supposedly!,i downloaded DfUse demo and instaled the drivers etc,loaded the DMR_clear memory file then tried to install the new firmware with the nano in dfu mode,it all went ok,said file uploaded ok,now the big but,when i poer the vna on,i get the same f/w version number displayed,it looks exactly as if nothing has changed,even my old cal data is there,it says uploaded ok but obviously hasnt uploaded a thin,any ideas?,73 m3vuv.

author: xrunner
author_rank: Super Contributor
timestamp: December 03, 2019, 01:21:39 pm
content: m3vuv, I don't know what the problem is, might try a different version of firmware from another source.Great new manual for the NanoVNA from Prof. Gunthard Kraus, go to the link and then the content. You can download the PDF file.Tutorial in three parts (Version 1.4.2. / December 2019) for the NanoVNA Vector Network Analyzer

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 01:46:45 pm
content: This is why I didn't futz with mine

author: xrunner
author_rank: Super Contributor
timestamp: December 03, 2019, 02:01:41 pm
content: Quote from: bd139 on December 03, 2019, 01:46:45 pmYou don't like mini-bricks?

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 02:04:54 pm
content: Quote from: xrunner on December 03, 2019, 02:01:41 pmthere is no way to brick NanoVNA. You can always reflash it.

author: xrunner
author_rank: Super Contributor
timestamp: December 03, 2019, 02:06:16 pm
content: Quote from: radiolistener on December 03, 2019, 02:04:54 pmI know that ... it's a joke.

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 02:12:53 pm
content: I could brick it!Too busy using mine to play with firmware! So this lunch time I built a small HF amplifier based on W7ZOI's termination insensitive amplifier notes to go in the middle of a receiver I am building. Target 15dB across 80,40,20m bands. I think we have a winner. Pretty flat gain across HF (not bad for 2n3904's):Good return loss:

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 02:31:39 pm
content: bd139, it's dangerous to put amplifier output directly to CH1.NanoVNA input expects -10 dBm level.In your case it's about +5...+10 dBm. This is too high.I recommend to put attenuator equals or higher than amplifier gain on the output and about 20 dB on the input.After such experiment, I would check if the СH1 port is still working properly. There is a high risk to burn it

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 02:45:31 pm
content: Yeah there's 20dB in thereEdit: This is a small signal amplifier so it's on the input. If it was a large signal I'd put my 200W 40dB power tap on the inputEdit 2: also I need to test RL of input properly still. I'm testing the 20dB attenuator there

author: xrunner
author_rank: Super Contributor
timestamp: December 03, 2019, 02:46:32 pm
content: He's attenuating the input to the amp to test it's gain.

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 02:48:15 pm
content: Quote from: CJay on December 03, 2019, 02:40:42 pmhe put attenuator on the amplifier input, but amplifier output connected directly to the NanoVNA.NanoVNA full scale is about -10 dBm, which is displayed as 0 dB on the S21 graph.As you can see there is +15 dB on his S21 graph.It means that there is at least +5 dBm level on CH1 input. This is too high.But we cannot be sure that the level is not higher that +5 dBm because input level is close to overload level. So, it's very possible, that input is overloaded and we see just a max possible value with a curve due to calibration.So, there is possible much higher power on the input. This is why I suggested to check if CH1 still works ok...I suggest to never exceed 0 dBm level on the NanoVNA input.And for more reliable measurements it's better to not exceed -10 dBm.

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 02:53:02 pm
content: Doubt it's a problem otherwise it'd blow up when you did the through calibration.OUTpwr + -20dB + 16dB = INpwrTherefore INpwr < OUTpwr is always true.Edit: for reference, the 20dB attenuator is calibrated out above. Perhaps that's where it is confusing?

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 02:56:09 pm
content: Quote from: bd139 on December 03, 2019, 02:45:31 pmin order to do that you can calibrate NanoVNA through 20 dB attenuator. The dynamic range will be 20 dB less of course.Another way is to attach dummy load on the amplifier output and connect CH0 directly to amplifier input. But it may saturate amplifier. NanoVNA ouput is -10 dBm, so you're needs to check if your amplifier can handle such input power with no saturation.

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 03:00:36 pm
content: Input can handle that fine. There is major gain compression though according to LTspice. I'll run it and see what happens.

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 03:01:26 pm
content: Quote from: bd139 on December 03, 2019, 02:53:02 pm+5-20 = -15 dBm, that's looks good.But I never connect amplifier directly to NanoVNA input, even if it's gain is not high.Attenuator also add protection from short transient pulses.

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 03:02:25 pm
content: I did measure output first with power meter to make sure it wasn't over expected rangeWorst case I have some surface mount SA612's here

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 03:05:31 pm
content: Quote from: bd139 on December 03, 2019, 03:02:25 pmThey are not so cheap, in my local market their price is about 3.20 USD...

author: bd139
author_rank: Super Contributor
timestamp: December 03, 2019, 03:14:03 pm
content: I got a whole strip of 50 in an ebay junk parts lotUpdated plot:20dB moved to VNA input. Looks like there's no gain compression at HF. I think there probably is after it hits ~ 300MHz as it uses harmonics and higher output power from the si5351A then. I don't go that high. Perhaps Siglent will get some business if I ever need toThis is only used at the receiver front end to 14Mhz before the first mixer and the rest of the IF strip is 4.915MHz so it's not exercised hard!

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2019, 03:22:22 pm
content: Quote from: bd139 on December 03, 2019, 03:14:03 pmyes, from 0 to 300 MHz it uses 2 mA output and 8 mA above 300 MHz.But since your sweep within 300 MHz band, it is always 2 mA.

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 03:29:28 am
content: now after clearing all the cal data and doing more cals in pos0 pos1 and pos2,ie hf vhf and uhf in the respective save positions,with ch0 open it reads on recall pos0 reads 2000-1 swr,on pos 1 open reads 2.1-1 swr and on pos 2 reads 2.07-1,any ideas whats wrong with this fooking pile of poo?,its soon going to turn into a nano flying machine at this rate!!

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 04:25:24 am
content: found this on iogroups,it solved my issues:Problem solved !I'm running the new Nanovna-Q software from Nov. 26.Before calibration I did the RESET, sure. The calibration resistors are OK, I have two, one that came with the NanoVna and one from MiniCircuits.The RESET procedure was the problem:I did not realize that I also need to SAVE to Cx right after Reset. Otherwise the data isn't really cleared and remains in the memory.If I remember correctly in previous firmware versions the RESET automatically cleared the memory loction without having to save actively.Whatsoever, now it works fine again. Thanks for your inputs !

author: radiolistener
author_rank: Super Contributor
timestamp: December 04, 2019, 05:10:21 am
content: Quote from: m3vuv on December 04, 2019, 04:25:24 amThis is incorrect information. Save is not required after CAL RESET. You can don't use save at all and use calibration until power off. Save operation is needed to recall calibration after power off.Also, when you're doing clearconfig command there is needs power off before any save operation, otherwise save operation will restore old bad configuration and it will needs to repeat clearconfig again.

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 06:47:15 am
content: if you know better i suggest you try calibrating say 3 frequency ranges and do what you say and check your readings on the ports open and shorted if you think you know best,doing it your way caused me loads of grief,sounds like your mouthing off without having done what you tell others to do,Mr bad advice knowall!!

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 06:49:06 am
content: NOTE: This message has been deleted by the forum moderator Simon for being against the forum rules and/or at the discretion of the moderator as being in the best interests of the forum community and the nature of the thread.If you believe this to be in error, please contact the moderator involved.An optional additional explanation is:

author: radiolistener
author_rank: Super Contributor
timestamp: December 04, 2019, 06:55:27 am
content: Quote from: m3vuv on December 04, 2019, 06:47:15 amdude, I do that a lot of time when debugging NanoVNA firmware.Since you're wrote that you're using my version of NanoVNA firmware, if you have found a bug, just add issue on github and I will fix it. But I don't see that behavior, that you're talking about.

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 07:00:43 am
content: so send me a link to your firmware,i will see if its what im using,i doubt it is.

author: radiolistener
author_rank: Super Contributor
timestamp: December 04, 2019, 07:42:36 am
content: m3vuv, it's amazing how many problems you have with NanoVNA. I'm wonder why other peoples don't have so many issues?It’s doubly surprising that you complain about problems and at the same time swear at those who help you to solve it.

author: m3vuv
author_rank: Super Contributor
timestamp: December 04, 2019, 07:56:17 am
content: your solution if followed would be the cause of problems,whats this software youve writen then,send a link to it,i suspect its more bullshit tho so doubt you can!

author: bd139
author_rank: Super Contributor
timestamp: December 04, 2019, 08:23:21 am
content: Wow this went off the rails when I was unconscious.Mine works fine. Everything wrong with it was me doing stupid stuff as usualThat might be because I didn’t futz with it though

author: xrunner
author_rank: Super Contributor
timestamp: December 04, 2019, 01:27:26 pm
content: Quote from: m3vuv on December 04, 2019, 07:00:43 amGo here -http://gunthard-kraus.de/Get this manual the guy wrote for the NanoVNA -"New: Tutorial in three parts (Version 1.4.2. / December 2019) for the NanoVNA Vector Network Analyzer for 50kHz up to 900MHz and a price below 50 Euros. And for the software "nanoVNA-saver.exe"and see if it has any info that might help you.

author: chris_leyson
author_rank: Super Contributor
timestamp: February 09, 2020, 01:52:27 pm
content: My NanoVNA-F arrived Friday, first impressions, not good. It's one of thesehttp://deepelec.com/2019/11/27/about-nanovna-f-machines-vendors-and-bad-clones/I see what BH5NHU means about the S21 noise floor. The isolation between port 0 and port 1 is pretty crap above 250MHz but that is not surprising.Just done a full cal and S21 through is -26dBI see the problem, port 0 SMA is slightly wobbly, FFSThis will require a big soldering iron to get the screening can off and I've only had the thing for two daysConsider buying one with the SMA connectors attached to a bulkhead. Maybe I can rescue things but I'm not sure. First impressions were good but they've gone rapidly downhill.EDIT: Screening cans are clip onJust reflowed the centre pin and the connector dropped off ! Looks like the connector had four ground pins originally but there are only two left. There is no sign of any solder on the remaining two pins and these are the pins that were soldered to the underside of the PCB, the screening can side. There are ground pads on the top of the PCB but no solder. Luckily I have a replacement connector, pictures to follow.

author: ogden
author_rank: Super Contributor
timestamp: February 09, 2020, 02:28:56 pm
content: Quote from: chris_leyson on February 09, 2020, 01:52:27 pmDamaged port2 (thru) mixer? You may want to reset calibration, connect through cable and check "uncalibrated" S21 thru level. Shall be around -10dB or so.

author: chris_leyson
author_rank: Super Contributor
timestamp: February 09, 2020, 03:09:53 pm
content: @ ogden. It was fine yesterday, I was probably ranting on about a broken SMA connector when you posted. I think I know where the two missing pins are, still soldered to the underside. I've only ever torqued up the connectors finger tight and that was lightly with two fingers, it's OK if you're not doing any measurements above 1GHz. If I tried I doubt I could snap the pins off an end launch SMA, I have a bit of FR4 somewhere with two name brand end launch SMAs fitted, I will have to give it a try in the name of science.

author: bd139
author_rank: Super Contributor
timestamp: February 09, 2020, 03:17:40 pm
content: When I bought the NanoVNA I was looking at other products. I figured if I broken one every 6 months and just threw it in the trash I'd be up cash on the next cheapest product still

author: ogden
author_rank: Super Contributor
timestamp: February 09, 2020, 04:07:28 pm
content: Those are easy to fix as well. Mine NanoNVA (clone) arrived broken. After port2 mixer (sa612a) replacement, it performs no worse than genuine NanoVNA. Picture shows how S21 "open" noise floor looks after calibration when port2 mixer is half-dead. Would be great for NanoVNA cal procedure to check mixer output levels against expected values and warn "unlevel" if they are way off. Now people may happily (try to) use broken/inferior NanoVNA w/o even knowing it.

author: DH1AKF_Wolfgang
author_rank: Contributor
timestamp: February 10, 2020, 03:56:03 pm
content: I own a NanoVNA and a NanoVNA-F (with 4.3 inch display). Both work without problems. I am surprised that the SI5351 oscillators work up to 300 MHz.By the way, I guess that most (amateur) users only use the S11 port anyway to adjust antennas...

author: virtualparticles
author_rank: Regular Contributor
timestamp: June 04, 2020, 09:20:41 pm
content: I evaluated a nanoVNA, probably the first version not an improved version if there is one. I measured a 12 dB return loss standard after doing a careful calibration. I measured 16 to about 20 dB. I don't know what one would do with a VNA that is as inaccurate as this. The standard measures a flat 12 dB +/- 0.2 dB on a real VNA. Both measurements attached.

author: bd139
author_rank: Super Contributor
timestamp: June 04, 2020, 09:22:51 pm
content: Can you take a picture of the board. Some of the eBay ones are hooky as hell.

author: ogden
author_rank: Super Contributor
timestamp: June 05, 2020, 03:38:22 pm
content: Quote from: virtualparticles on June 04, 2020, 09:20:41 pmThat is not original NanoVNA. Gecko version is far from best clone, at leastmany say so.QuoteYour nano most likely is lemon or improperly calibrated. Mine (clone that I fixed) is showing +/- 0.5dB upto 300MHz and +/- 2dB upto 900MHz. Could you show also S11 open and S11 load? Do you use same cal kit for both vna's?

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: June 05, 2020, 03:40:38 pm
content: Are they actually putting the copper mountin lizzard logo on that VNA?I am thinking of getting one of these, might be fun to play with.

author: radiolistener
author_rank: Super Contributor
timestamp: June 05, 2020, 03:43:44 pm
content: Quote from: TheUnnamedNewbie on June 05, 2020, 03:40:38 pmpreviously nanovna with lizard logo showed worse performance, but it was a long time ago.

author: virtualparticles
author_rank: Regular Contributor
timestamp: June 05, 2020, 04:49:59 pm
content: Quote from: TheUnnamedNewbie on June 05, 2020, 03:40:38 pmI'm afraid so. And Copper Mountain Technologies is not associated with this product in any way.

author: virtualparticles
author_rank: Regular Contributor
timestamp: June 05, 2020, 04:54:41 pm
content: QuotePerhaps it's a lemon? I guess I should purchase another. I used the same commercial grade calibration kit for everything. The supplied kit just isn't good enough to make useful measurements. S11 measured -7 dB (ish) with the open. This is the second unit I got from the supplier. The first one was completely unresponsive. I did perform the calibration properly. As a VNA designer I have a little bit of experience there. :-p

author: OwO
author_rank: Super Contributor
timestamp: June 05, 2020, 07:03:22 pm
content: Maybe try a different ebay/aliexpress store. I personally know this store sells good nanovnas (both -H and V2):https://www.aliexpress.com/store/all-wholesale-products/939205.htmlMost stores on aliexpress are a hit and miss, they source randomly and don't have any stock themselves.

author: ogden
author_rank: Super Contributor
timestamp: June 05, 2020, 07:45:47 pm
content: Quote from: virtualparticles on June 05, 2020, 04:54:41 pmUnfortunately. Your measurements are way off, port1 most likely is damaged. You shall take @OwO advice

author: radiolistener
author_rank: Super Contributor
timestamp: June 06, 2020, 01:20:58 am
content: you can try this seller, previously he sell good nanovna. I'm not sure if the quality has not degraded, but this seller sells other ham stuff and it looks good.https://www.aliexpress.com/item/33016805196.html

author: aristarchus
author_rank: Regular Contributor
timestamp: June 06, 2020, 02:34:03 pm
content: Got this and I'm really happy with results and with its quality. Good reputation store, many years in Ali with RF and tech.nanoVNA-H4->https://www.aliexpress.com/item/4000594700172.html