Who knows, if the firmware update to the latest 2.2.1.2.8 version violates the existing calibration certificate? I'm worrying, that this reflash process may irreversibly overwrite some internal calibration data of the unit.
Is it a safe process from this standpoint?
I found only below remark:
"CAUTION: User calibration data taken with previous firmware revisions will no longer be compatible with the instrument after upgrading to V2.8. You will have to store new user calibration files if you update the instrument", but I believe it is related to the calibration performed during OPEN-SHORT-LOAD, which could be easily repeated in a VNA mode.
What about (possible) accuracy degradation in a spectrum analyzer mode? I assume, there are some manufacturer's correction factors, which typically reduce internal errors (due to linearity, drifts etc.). Are they maintained, discarded, or switched to default ones?
Or maybe there is nothing to worry about? Did anyone experience any degradation in the accuracy after reflash?