Bob, thanks for the help. What you said about the CALSAVE and 50ohm not affecting impedance measurements is good to know and now makes sense of the data I saw. The spiral measurement is messed up is good to know.
I'm not an amateur radio guy but have an interest in RF stuff. Still trying to get my head around smith charts. The off the chart spiral didn't help me any. That isn't possible, right? I'm not sure what I did to stop it. I put version .61 back in to verify the hardware was ok and it seemed to be. Nice that the EEPROM data can be used from either version. I re-installed .70 and it still did the spiral thing. Think what made it finally go away was to do the CALSAVE 0 & 1 over, but I'm not sure.
nanoVNA-saver has crashed many times, usually serial port related.
Why does the measurement happen twice. It does the sweep, then about 25 seconds later plots it and then it does another sweep that it doesn't plot?
Is the ~25 seconds after the sweep all nanoVNA-saver calculating? Could it display a count down or something? Should I be asking the nanoVNA-saver author this kind of stuff or posting here?