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.