For your second question, regarding number of points:
Note that with recent firmware, many nanovna hardware models support 401
points. It sounds like that is what you have, since you are getting 2.5kHz
steps across a 1MHz range. The actual number of points used is settable
via the menus. Which version of firmware do you have? and which model of
nanovna? (can be seen on the startup screen, or on the config->version menu
screen for more recent firmware).
Very detailed thank both of you for the help. I have a Nano VNA-H 4 version 1.0.64
