The field line resonance (FLR) mechanism has become a cornerstone of magnetohydrodynamic wave theory in the magnetosphere and the solar atmosphere. Evidence for the mechanism comes mainly from auroral radar and geosynchronous spacecraft observations. Spacecraft in elliptical near-equatorial orbits (particularly Active Magnetospheric Particle Tracer Explorers Charge Composition Explorer (AMPTE CCE)) have seen frequency-varying oscillations of magnetic field lines but have not seen much evidence of the large-amplitude, narrowband FLRs seen by auroral radars. We simulate the resonance region of a large event observed at GOES 7 and also of a smaller-amplitude event we term a typical Scandinavian Twin Auroral Radar Experiment (STARE) event with reference to the STARE auroral radar results. One set of simulated narrowband FLRs is driven by a magnetopause Kelvin-Helmholtz wave. We add a fundamental continuum oscillation and analyze the resulting time series using the AMPTE CCE time-frequency analysis. We find that at the observed milliHertz frequencies the narrowband FLRs appear as large or small enhancements in the continuum of the azimuthal magnetic field but are not obviously monochromatic. For large events, enhancements in the spectrum of the compressional magnetic component may suggest a narrowband driver. We also analyze FLRs driven by waveguide modes and find no monochromatic signatures in the compressional magnetic field.¿ 1997 American Geophysical Union