The Hilbert transform produces uninterpretable results on broadband data. You will need to narrow-band filter the signal first. This video shows one method of computing an FIR filter and applying it to EEG data. Together with the Hilbert transform, this gives us the filter-Hilbert method. It is about 30 minutes long.

Download the Matlab script for FIR filtering.
Designed, created, and maintained
in html5 by Mike X Cohen.