A model for the magnetospheric effects of ELF/VLF modulation of the auroral electrojet using high-power ground-based high-frequency radio waves is developed. The effects of ducted topside whistler wave power flux, as generated from ELF/VLF auroral electrojet modulation, on the magnetospheric equatorial pitch angle diffusion coefficient are computed for a range of ELF/VLF modulation frequencies. We find that the precipitation lifetime in the presence of this whistler wave flux is smaller than for purely collisional processes. We find that aspects of the model are in agreement with recent experimental observations.