A disclosed nuclear magnetic resonance (NMR) logging tool includes a static magnetic field source. The NMR logging tool also includes a pulsed magnetic field source with an operational range corresponding to a predetermined frequency range and a predetermined amplitude range. The NMR logging tool also includes a controller in communication with the pulsed magnetic field source. The controller performs a calibration for the pulsed magnetic field source to optimize an NMR parameter. The calibration uses a reduced search space within the operational range to select a frequency and an amplitude that optimize the NMR parameter.