Anyone following Hackaday and other hobby electronics blogs/YouTube channels has probably noticed the buzz around the NanoVNA lately. Admittedly I don’t know a lot about it, other than the fact that the design and firmware is open source and now a bunch of Chinese manufacturers have started making it and that you can now get one for around $50 to $60, shipped to the US.
A VNA is the one bit of test gear that was missing from my stable, so hearing about the possibility of getting one for cheap right now certainly piqued my interested. However I wasn’t interested in wasting money on a glorified toy, so I didn’t jump on it immediately after hearing about it. The buzz about it kept growing and I started hearing enough good things about it that I finally decided that I could live with taking a chance on losing $50 if it didn’t pan out, so I pulled the trigger a few weeks ago and ordered one from eBay.
The NanoVNA arrived a few days ago, decently packaged in a reusable plastic box that included a couple of USB-C cable, SMA coax jumpers, a SMA female passthrough, and a calibration kit. As is often the case, the instrument is even smaller in person than it looks on camera. The length and width are roughly the size of a credit card, and it’s perhaps 1 cm thick. Very compact!
So far, I’m pretty impressed by what you get for your money. The user interface can be controlled with the rocker switch you can see at the top-right, or with the touchscreen (you’ll need to use a stylus if you have fat fingers like I do). Calibration is easy to perform and the menus are straightforward to navigate. In the photo above, I’m measuring the return loss of one of my HT antennas, and you can see that it has proper dips at 2 meters and 1.25 meters. Other quick checks that I have made of antennae, filter responses, etc. have all looked exactly as I would expect.
There is also a PC program that can run on Windows that will connect to the NanoVNA’s virtual serial port and display plots on your PC, as well as allow you to capture plot data. It works OK, but could use some refinement and additional features. Unfortunately, this program is not open source, so we are reliant on the author to make those updates. I do know that the serial interface is easily exposed, so I bet some more options in this area will be coming soon.
But what about the accuracy, you ask? I don’t have any calibrated instrumentation to compare it to, but multiple members of the NanoVNA mailing list have compared it to an HP 8753C and from their reports, it compares quite favorably. For home lab usage, it looks like it will be more than adequate. I might also point out that the device is excited by a Si5351A, which doesn’t surprise me in the least. When I first was made aware of it years ago (when I did the Si5351 Investigations series), I figured it would almost certainly find its way into all kinds of ham radio and other RF related stuff.
So far, I’m glad I purchased it and I feel like it’s a great value for the money. What an excellent time to be an RF experimenter, where tools that were previously very expensive and hard to get are now within reach of just about anyone!