To read the calibration values, you will need to load new firmware.? Vic's suggestion is one possibility.? N8ME is another (the one that I prefer).? I use the version with the VU3GAO mods that can be downloaded from the files section here: /g/BITX20/files/uBITX_6_N8ME_2_VU3GAO_Mods.zip
The manual is in the zip file download.? You need the Arduino IDE to load firmware.? Ashhar Farhan has a video on how to update firmware on the V6 here:
The Arduino software is here:
There is documentation on the Arduino site on how to use the IDE.