  We report proof-of-principle measurements at the neutron resonance spin echo
spectrometer RESEDA (MLZ) under large magnetic fields by means of Modulation of
IntEnsity with Zero Effort (MIEZE). Our study demonstrates the feasibility of
applying strong magnetic fields up to 17\,T at the sample while maintaining
unchanged sub-$\mu$eV resolution. We find that the MIEZE-spin-echo resolution
curve remains essentially unchanged as a function of magnetic field up to the
highest fields available, promising access to high fields without need for
additional fine-tuning of the instrument. This sets the stage for the
experimental investigation of subtle field dependent phenomena, such as
magnetic field-driven phase transitions in hard and soft condensed matter
physics.
