NanoVNA Is A $50 Vector Network Analyzer

There was a time when oscilloscopes were big and expensive. Now you can get scopes of various sizes and capabilities on nearly any budget. Vector network analyzers — VNAs — haven’t had quite the same proliferation, but NanoVNA may change that. [IMSAI Guy] bought one for about $50 and made a series of videos about it. Spoiler alert: he likes it. You can see one of the several videos he’s posted, below.

NanoVNA is tiny but sweeps from 50 kHz to 900 MHz and has a touch screen. The device uses a rechargeable battery if you need to haul it up to an antenna tower, for example. Just as a quick test, you can see early in the video the analysis of a rubber duck antenna. The device shows return loss as a plot and you can use a cursor to precisely measure the values. It also shows a Smith chart of the reactance.

If you don’t like the touch screen, you can also control the device via USB. You need software from Google Drive and you can also get the manuals from there. In addition, there are additional firmware files available so you can reflash the instrument. For example, you can limit the top frequency to 300 MHz or select a larger font.

You might wonder why you’d limit the frequency to 300MHz. According to the manual, the instrument has better performance under 300 MHz. There is also provisions for calibrating the device in the field.

For $50 it is pretty impressive. [IMSAI] guy also did a video about its accuracy, checking its output with a scope and frequency counter.

We’ve looked at other cheap VNAs although this one has an interesting range of frequencies compared to some we’ve seen before. We also put the Analog Discovery 2’s VNA through its paces. It costs a good bit more, but also does other things, but the VNA tops out at 10 MHz.

 

42 thoughts on “NanoVNA Is A $50 Vector Network Analyzer

  1. Beautiful toy….perhaps I´ll buy one just to play a little, because upper frequency limit is too low for my applications.(at least 3 GHZ) But, at this price….
    ct1xv

          1. Yeah..for us (me) amateurs is far from budget. I did use a PLL LNB with 10 ghz local oscillator (shack modif…) together with a SIGLENT 3021X and signals are there, this for a Spectrum Analizer: The same extension can be made with VNA, I think. As VNA I use a MINI VNA TINY, but I would like to build one. There are plans for a 6 ghz VNA from HENRIK FORSTEN (google $200 VNA), but my sight doesn´t help any more, 73- ct1xv

        1. Geekcreit is a 30(?) – 3 GHz sweep osc, mixer, log detector & tracking osc. $35-$60

          You’ll find these obscure links useful. No specs from BG, but hardware schem appears similar to ‘D6’ at github but I haven’t tried reflashing stock firmware with it, and the PCBs look different. Same chips and connections though.

          https://www.rudiswiki.de/wiki9/SpectrumAnalyzer_LTDZ
          https://github.com/joseluu/D6_firmware
          alloza.eu/david/WordPress3/?p=542

          Not a sensitive spectrum analyzer; could use a gain block between the mixer and log-det.
          If you want it for network analyzer, antenna sweeper, get the BG antenna bridge and calibration plugs, detailed in top links. More links there.

  2. He likes it.

    It outputs a square wave instead of a sine wave and output above 300MHz seems to be broken.
    And that’s *just* the test signal to the component.
    And in the first video, he reviews it without knowing this.

    1. Some of the low-end VNAs from more renowned brands (like Keysight) also outputs squarewave. It’s fine for testing passive stuff like antennas.
      For a brand-name VNA on a budget with a great sine generator you would need something like the R&S ZNLE3. But that’s still out of reach from hobbyists.

    2. It measures the >300MHz band using the harmonics of the square wave. Not really a problem, many low-end ‘professional’ VNA’s also measure like this. As long as you are not measuring a broadband active device the result is as good as with a sine wave. You can use a band-pass filter to measure something active, but the calibration is non-trivial.

      1. not with a unit like this–it only exposes the test ports and does not have the traditional r/s/s2/if etc ports needed for more advanced test setups. Trying to add mixers would basically require building a ‘real’ vna around this unit

    1. Things are always depending…
      for somebody working on Very Low Freq the 50khz is too low.

      For somebody working on 5 GHz the 2.4 would be too loy.

      Always it gives something to complain….

  3. I just picked up one last week for doing uhf antenna work have only been having a play with the settings and controls but so far seems like a good buy – but it’s closer to A$100…

  4. I was intrigued by this but had no idea what it actually did in terms I could understand.

    https://en.wikipedia.org/wiki/Network_analyzer_(electrical) Covers it quite well.

    As far as I understand, it plugs into “both” ends of a device (aka network) providing it input and measuring output. A typical “scalar network analyzer” measures the ratio of input to output (which tells you the transmitted signal power), a “vector network analyzer” like this also measures any change in phase.

    I’m sure that will be clear to most from the article.

    1. I was going to say something along these lines.

      They aren’t a new thing, but previously so expensive that hobbyists had no contact, unless at work. Slowly I’ve seen references, but there seems to be an expectation that we would know what they are and how they are used. The fancy name masks their function, really a display, a generator and a receiver. But i integrated, it makes it much easier.

      I recently saw someone check crystal filters with a home made vna, it’s just easier, but the same thing coukd have been done with multiple pieces of test equipment.

      I’m not dismissing vna’s, just pointing out that they aren’t so unfamikiar after all.

      Michael

  5. Interesting. When I worked at HP about 30 years ago and had to design matching networks to go on PCBs, I used expensive VNAs a lot. At one point I created an excel spreadsheet that would calculate component values for different matching networks and interfaced with AutoCAD in which I had created a replica of the Smith chart. It would plot the s-parameters and impedances over frequency of whatever network components the spreadsheet calculated. I showed it to a few people and it got bounced up the chain of command until it hit some corporate lawyer’s desk. He promptly killed it off because we hadn’t licensed the copyrighted (or was it patented?) Smith chart from the family of Dr. Smith who still controlled it. Now I see a Smith chart on the display of this device. I wonder if the Smith family knows about it…

    1. That’s interesting. I used to use an HP network analyzer that had a Smith chart built in as a pushbutton option. “A” equals return loss, “B” equals Smith chart. You must have hit a lawyer in the sales prevention department.

  6. Found this neat Spectrum Analyzer and VNA system that I moved forward with investing in modules and components for since I thought would be a good hands on study project for the winter season:

    In general: https://github.com/erikkaashoek/Tapr-VNA

    The schematic: https://github.com/erikkaashoek/Tapr-VNA/blob/master/Doc/VNA%20current%20bridge.pdf

    From this folder: https://github.com/erikkaashoek/Tapr-VNA/tree/master/Doc

    More images:
    https://groups.io/g/HBTE/message/322

    Block diagram update:
    https://groups.io/g/HBTE/message/416

      1. Well you get connectors and other accessories.

        Is it really official, or just more prominent/trudtworthy? With a lot of these cheap gadgets, it’s hard to tell if anyone came first. Or something started as a home project, those $16.99 frequency counters or component testers, and then endless clones. Sometimes they may not be endless clones, just a few clones with endless resellers.

        Noelec certainly takes a lead for those cheap usb sdr gizmos. I finally bought one last week, bought a noelec since for a few more dollars it came in a metal case.

        1. I bought one from nooelec and it was ok but more expensive as you say. I don’t know about ebay but I see this at Alibaba https://www.alibaba.com/product-detail/Original-2-8-Touchscreen-50KHz-900MHz_62232701280.html I haven’t bought from them though.
          If you want the original you should look for one by hugen. I find the http://www.nanovna.com web site to be the best source of info on this or the groups.io site I mentioned above. Hugen himself would send you to another Chinese website that I couldn’t get to work.

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