So did you ever notice that the reading of S11 is pertubated if you touch or
not the nanovna. even if the nanovna is on the table
and my hand get close to the vna there is fluctuation in the reading
My unshielded "worse" clone is quite immune to proximity effects.
In fact, the only time it became a problem was an SMA cable gone defective,
presumably a poor crimp between connector and cable braid
Oristo