When you get your new Hermes Lite 2 or Anan SDR transceiver, dowload and install the Thetis software.
Running Thetis for the first time will create the FFT Wisdom file , it will create a forward and backware FFT starting at 64 and ending at 262144
FFT Wisdom filename is: wdspWisdom00 (it is a hidden file)
To locate the wdspWisdom00, start file manager turn on: File name extensions and Hidden items.
Location is: C:\Users\Your computer name\AppData\Roaming\OpenHPSDR\Thetis-x64\VE7ED-wdspWisdom00
Note: Probably good to make a backup of the file.
You can just delete it and restart Thetis it will go through the creation of a new FFT Wisdom file.
This where you can find out the file properties.