Electron detectors on the Echo 7 active sounding rocket experiment measured ''conjugate echoes'' resulting from artificial electron beam injections. Analysis of the electrons' drift motion after a complete bounce led to measurements of the magnetospheric convection electric field mapped to ionospheric altitudes. The magnetospheric field was highly variable, changing by tens of millivolts per meter on time scale of as little as hundreds of milliseconds. Sets of double probes on the payload measured the ionospheric electric field directly. While the smallest-scale magnetospheric field irregularities were damped out by ionospheric conductivity, larger-scale features were enhanced by up to 50 mV/m in the ionosphere. The mismatch between magnetospheric and ionospheric convection fields indicates a violation of the equipotential field line condition, i.e., the existence of parallel electric fields above the payload. The parallel fields occurred in regions ~10 km across and probably supported a total potential drop of 10--100 v. The flight took place in the premidnight diffuse auroral region and therefore was likely in a region of downward field-aligned current. There is some evidence that the parallel fields also pointed downward and so could be responsible for creating the field-aligned current by drawing electrons out of the ionosphere. ¿American Geophysical Union 1991