| Its performance is nowhere comparable to a real VNA, those VNAs made by Hewlett-Packard in the late 80s are still the golden standard for many labs. But NanoVNA is great value for the money for anyone interested in radio electronics! For $50, almost nothing beats a NanoVNA, and it's much more effective than the traditional sweep generator setup. You get complex S11/S21 and 900 MHz bandwidth [0], good for measuring complex impedance, the insertion loss of the coax, the frequency response of filters, SWR of antennas, and even basic Time-Domain Reflectometry. The firmware is available under GPLv3 for hacking as well. I recently used it to experiment different ferrite RF transformers for my homebrew radio receiver, and to characterize frequency response of inductors. The only thing to beware - since it's a "almost" free hardware design (i.e. FOSS firmware + a block diagram for hardware, only the PCB layout is not available), there are a number of low-quality clones that use low quality components and don't include proper shielding. I recommend hugen79's version ("NanoVNA-H"), he is not the original designer (it was designed by edy555 [2]), but hugen79's version is currently the most common source with reasonable quality, see the picture for comparison. [1] [0] > 600 MHz uses higher-order harmonics, and is less reliable, but still better than nothing. [1] https://github.com/hugen79/NanoVNA-H/blob/master/doc/clone.j... [2] https://github.com/ttrftech/NanoVNA |
I think the whole NanoVNA eruption (including the clones and alternatives) is outstanding. I believe there is a large unsatisfied demand for low performance instruments that are sufficient for experimentation below ~3 GHz. There are a lot of used instruments around that are large, heavy and usually need service, and there are a number of built-down-to-a-price entirely proprietary instruments from Asia, but nothing beats a device that fits in your hand, runs free code from GitHub and costs so little that you can fry it accidentally and not care much.