Review

Great VNA, much better than the NanoVNA types. Much faster, higher dynamic range and higher frequency range. And true dual port. Also the designer of the hardware and the software is very responsive. The only downside is that the unit gets quite hot. I run it from a 5V/2A USB power adapter. Too bad it is not included in the package.
The PC software is very capable but it does take some time to figure out how to use it. It is not always as intuitive as hoped for. But support from Jan is excellent. And the hard- and software is completely open source, so you can modify it to your needs.