Raw Main Time (Bluetooth Spectrum)

Raw Main Time is the raw data read from the input hardware or playback file, before time corrections and software resampling:

This data has not had time corrections applied, so it displays a "CAL?" trace LED.
The data has not gone through the VSA's software resampling filters, so is generally not sampled at the specified sample rate.
The data has a wider bandwidth than the measurement span would indicate.

Raw Main Time data is useful when hardware trigger types are used (to see what caused the trigger) and when a recording is played back (to see exactly the samples saved in the recording).