Відео

Merci pour ce comparatif, hyper intéressant ! ;)

Very interesting and clear! Thank you very much (for the utility gnuplot too !!! )

Very comprehensive and interesting. Thx for sharing!

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.

one of the "pussyble" ... LMAO =)

What type of oil should I use?

This is a great tip! It does not work for measuring DC and AC at the same time though... as far as I can tell.

Just put a new motor in.

Can I measure temperature and dc voltage at the same time ?

Thank you for the range tip. I hadn't realized that. A tip from me is that you can meassure the current on the low side of the load. By this way you will able to measure the voltage correctly on the high side. Thank you for the video. Kostas

8:01 As far as i know induction motors speed can change based on the alternating current frequency or the number of poles, with the windings you might be changing the number of poles, the draw back is it lowers the torque and cause over heating of the motor. is better to leave the wiring to what the manufacturers set it to.

you didnt turn the gas back on!

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!

Very helpful! Thank you!

Hello. I'v also designed time base for counter JDS6600.

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?

Have you or anyone else taken the next step to hack and integrate with an ESP8266 to allow for Alexa control?

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

Not ceramic fuse?! argh...

شكرا على الفيديو.سؤالي ما مدى اختلاف القياسات أن وضعنا أكثر من مقياس من نفس النوع بقراءة الجهد والتيار !

I wonder if the low battery alarm also goes out over the network?

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 mentioned bearing. Your motor is not a bearing type, it is a bushing and it needs oiling.

اتمنى الحصول ببلدي على اجهزة قياس حديثة سوأ حظي بلدنا انهكته الحروب بسوريا . لكن بما انه مضى 2 سنة على نشرك الفيديو هل مازلت تستخدمه بشكل جيد

Thank You, I had a noisy motor, it got hot and I followed your instructions and reoiled!!! Back up and running, smooth and quiet now.

I too am in the middle of my replacement cycle. Thanks for making the video. Great use for your old detectors.

Why not try the LibreVNA ?

Nice upgrade!

Hi there, i discovered your channel by mere coincidence, great content...keep up the good work👍 but i was wondering about your shielding, the 1st one in particular, aren't you changing the microstrip impedance by adding an extra layer of ground above it? try to change the height of the shield to see if it affects the readings to confirm this theory, maybe you can try not to ground the shields 😶‍🌫? i also suspect that the usb connection might affect things here( grounding issues?) i would really like to see the results, it would be fun and educational to find the culprit or to confirm that it's a bad PCB layout issue. Merci beaucoup et bon courage pour la suite😉

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.

I like the design for the PM6666 ocxo and would like to ask if you have a PCB leftover ( if gerber files are available I would very much appreciate it !) ? br Erik from Denmark

very helpful 🙂

can you mirror the DMM6500 display onto a monitor by simply using a USB to HDMI adaptor ?

Does this multimeter reset calibration if the battery runs out? (CR 2032?) Is this really true??? And will it need to be carried to a special laboratory for accurate calibration? Is it somehow possible to calibrate this device without a lab? Is it possible to somehow enter data (calibrate) the wires (probes)? (Let's say I bought other wires and want to account for the capacitance/resistance etc of the new wires)

Is there such a thing as a 5V transformer? In other words, can you downgrade the transformer you have to something smaller like a 5v ?

Although it is doubtful that shielding is the solution for the problem, you should try with a shield tape that has high permeability. I used to have an RF shielding tape kit that had all kinds of options, but you can't get that kit anymore.

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.

replacing blower motor on my furnace. problem is it's an old unit (pre 1988) and they have updated the motor. the new motor has 4 wires plus the 2 capacitor wires and the original motor had 5 wires plus the 2 capacitor wires. the difference according to the motor tag is the original motor had two med speeds and the new motor only has one med speed. can I wire it up with one med speed? do I use med lo wire, med hi wire or both med to the new motor? ty for any assistance you can provide. 🙂

Just plug a GPSDO into the external ref jack. Far easier and more accurate.

Thank you for sharing this video.

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.

good job . I recommend you add to the v reg circuit add a bypass diode between the VIN and VOUT terminals of the reg (reverse-current bypass diode) This is standard in Liner Voltage Regulators design

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

Thank you for uploading more often! Really loving your videos. Maybe a suggestion for the future: The graph colors in the legends looks all black. It is impossible to read which graph should be which color in the legend. Maybe make the legend graph lines a bit bigger, so you can see which color is which. Thanks 🥰

Fascinating...cheers.

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

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 :-)

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.

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

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.