@ Jim : Thanks Jim for considering & commenting. I think I will try it out then - possibly with a JFET probe in-between the PSU & the VNA to see if there are any differences between the end of a 50 ohm coax (with suitable DC isolation) and the JFET probe.
Now, then I "just" need to find out which nanoVNA will work with Joe Smith's software and also go sufficiently low in frequency ...
BTW: Can I ask what you are working with (or "hobbying with") since you work with ADCs?
Cheers,
Jesper
