Important note: From version 20.2 on, blackbird cap files can be processed directly!

• Load the file as raw data into Audacity. Use the following settings:
  • Signed 32 Bit
  • Big Endian
  • 2 channels (stereo)
  • Offset 512 Byte
  • Sampling rate depends on the recording
• After loading, amplify the signal for a peak level of -20 dB.
• Export to a wav file
• Use the wavtext tool to add the following metadata into a txt file:
  • File type: complex
  • Sampling rate depends on the recording
  • Center frequency depends on the recording  

That's it

If you have many files, write a batch file for automatic processing
You can also use SOX instead of Audacity to do the conversion.