H-2-NMR in three different magnetic fields and small angle X-ray scattering (SAXS) are employed to investigate the orientational order, molecular organisation and phase transitions of the chiral smectic liquid crystal (-)-(S)-[4-(2-methylbutyloxycarbonyl)phenyl] 4-n-heptyl-biphenyl-carboxylate (MBHB) suitably deuterated for H-2-NMR measurements. Unwinding of the ferroelectric chiral helix by high magnetic fields is observed and discussed. Tilt angle values are obtained with the two different techniques and compared. The results show the importance of molecular conformation for the structural properties of this mesogen.