Hi. Few questions:
1) I organized the name format of the .cal files stored in the microSD card of my NanoVNA-H4 as per the image in order to easily find them, as only capital letters can be used and dots / commas aren't available. How about you?
2 ) Have you tried to rename them with the PC in order to also use the lower case letters, commas, etc. (e g. 1.8MHz-29.7MHz.cal)? Did you get issues?
Many thanks.