This investigation provided continuous, sheath-independent measurements of the electron-density profiles at Jupiter and Saturn. It also gave basic information on local wave-particle interaction required to carry out comparative studies of the physics of the Jupiter and Saturn magnetospheres. The instrumentation consisted of a 16-channel, step-frequency receiver and a low-frequency waveform receiver, with associated electronics. The frequency range for this instrument was from 10 Hz to 56 kHz. This instrument shared the 10-m antennas developed for the investigation of planetary radio astronomy.