Interesting and informative review! I don't do RF work but find this equipment interesting. I studied books in the 70's to get a first class FCC license but haven't ever used that in work. This review and that on the TinySA show that this technology can be obtained for a reasonable cost for schools and hobbyists. I got the TinySA just for kicks but not sure what I would do with the VNA. Thanks for two well done videos. I know it takes lots of time and effort.

The SAA2 VNA uses a different DDS to the NanoVNA. The NanoVNA uses a SI5351 which can only generate frequencies up to 300MHz and uses harmonics to get above it. This reduced dynamic range significantly. The SAA2 uses an ADF4351 which can generate RF up to 4.4GHz without resorting to using harmonics, resulting in a better dynamic range across the board. Newer SAA2 revisions use the MAX2871 which is very similar to the ADF4351 but can sweep up to 6GHz. As you say, the shielding will also help with the SAA2. I also own a NanoVNA, one of the original SAA2 VNAs and a Siglent VNA :-)

Yes, please do a video about the Siglent. Also, a full lab tour would be interesting! Thank you!

Thanks a lot for zour effort and the great comparision!

As Andy mentioned DDS are different in you VNAs. That is very important, because RF generator output power is much lower when using 2nd harmonic and even lower when using 3rd harmonic, and if we say RX sensitivity and noise stays the same, you get much worse S/N ratio (you get more noise compared to the signal) on higher frequencies. Shielding would help, but just to a point. When you calibrate VNA it offsets that very low (2nd or up to 5th harmonic) signal level with big gain to get 0dB trace at all frequencies, so it is mostly RF generator output level problem. RX sensitivity is also getting worse at higher frequencies, because of higher mixer conversion losses, which is another 'RF signal level' problem. Inconsistencies between measurements are also due to cable bending (since those cables are not phase stable), SMA tightening and some common mode current outside the coax. It would be interesting to take one measurement with Siglent, then disconnect cable, connect it again to Siglent and taking second measurement. I suspect you would get almost the same difference as you did with comparison to SAA2. That would show cable bending and SMA tightening contributions plus other measurement uncertainties.

NanoVNA-H is the old V1 version, Si5335 based, that works on harmonics above something like 300MHz, so no wonder it has much worse specs. Si5335 synthesizer chip official spec: fmax 200MHz NanoVNA V2 is new version based on 2x ADF4350 with official fmax of 4400Mhz, so no harmonics needed. NanoVNA-F V2 clone version with somewhat better/nicer mechanical design, aluminum case instead of plastics, for a bit more money

Fascinating...cheers.

very helpful 🙂

Great video. Can you make a video on upgrading the SSA3021x to SVA1032x ?

The white Nano is a clone and the results you are getting are probably due to that fact. I have a modified clone H and an original H4 and those do not exhibit that kind of behaviour. Try NanoVNA Saver software and do not calibrate on device. Saver will offer much higher number of calibration points and a correction for the trough measurement. Makes sure that you get the latest firmware. DisLord firmware is recommended.

Ótimo vídeo

Good review and very important points! The problem is you never know what you get when you buy cheap of of china/ebay/aliexpress... Even when one version was tested good, they build new fakes and it gets worse - but you don't know unless you have the capability to really test your device properly. Thanks a lot!

Impressed with the SAA2. Very close to the Siglent. I've just bought the NanoVNA-F V2 enclosed in metal case. Also has 4 metal cans on the circuit board, so hopefully well screened.

Many thanks. This was a very interesting set of tests. Based on my own needs, my take away is that all three VNAs are very close to each other up to 400 or 500MHz and then they diverge, the "H" clone sharply so. Everything I do, though, is below 148MHz, and within that larger range usually test in much smaller spans of 10KHz or so and once in a while 200 or 300KHz. All below 148MHz. Any of these--the two nanoVNAs or the Siglent--would be adequate for my purposes. The 10 and 20dB offsets produced by the H-clone is weird. I wonder if the very-wide bandwidth scanned in these tests has anything to do with that

Why not try the LibreVNA ?

Nice to see the comparison. I have nanoVNA-H4 from a reputable seller in The Netherlands and i suppose it is not a clone. The enclosure is a 'snap-on' type, so not easy to open up and look inside and say something about the shielding. I also don't have another instrument at home to compare, but could ask my colleague at work to do a quick compare. I have done some basic measurement filter measurements and on my EFHW 10m long antenna and could fine tune it with this nanoVNA. It all seems right, but once again not much to compare yet. About the port 21 isolation graph, that could be calibrated away? Or not?

When you take measurements from duplexers, put a dummy load on the unused port. Leaving the unused port floating ussually results in phantom troughs all over the place.

For the data processing I found exporting the s1p or s2p files and using Python with scikit-rf a nice tool too

stay under 300MHz, its a 30 buck clone product, tripping on harmonics in the GHz range, and expecting reference values. use it in its range to a frew hundred MHz and here it would have been relevant to see how it performed vs its price.

The best is...., a HP8753E, ya it cost money, then again, if you want to go down the 1/4 mile track in 7 seconds, your not going to do it with a 4 banger, Datsun! LOL!@

You sir take superfluous to a whole new level. Just sayin...

I wonder why people always insist to compare a basic toy like tool to a semi professional one. It is like comparing a Cozy Coupe to a mid size Chevy or Volkswagen.