[en] Routine monitoring of the plasmaspheric content was a primary objective of the ATS6 Radio Beacon Experiment (RBE) and this set critical requirements on transmitter and receiver stabilities. The satellite transmitted linearly polarized signals on carrier frequencies of 40.016, 140.056, and 360.144 MHz, with modulations of 100.04 kHz and 1.004 MHz. This provided coarse and fine scales of measurements so that the cycle ambiguity in the phase measurements of both Faraday rotation and group delay could be resolved. This report summarizes 140 MHz data recorded at the Boulder, Colorado, ground station (40.13 degrees N, 105.24 degrees W) while ATS6 was positioned above 94 degrees west longitude, between July 1974 and May 1975. The satellite appeared at an azimuth of 163 degrees, elevation 42 degrees, with the projection of the ray path near the ground. All data were digitally recorded once per second