A series of measurements of the relative flux density of discrete radio sources has been made at 475,710, 958, 1420, and 2841 Mc/sec, using a two-element interferometer. The flux density scale at each frequency has been fixed by referring these relative intensities to a series of calibration sources whose spectra are reasonably well determined. A complete list of the measured flux densities is given here, along with a de- scription of the experimental technique and a discussion of the sources of error. At each frequency the uncertainties in the relative flux densities are typically between 5 and 10%. Because of the similar observing and reduction technique employed at each frequency, the results form an especially self-consistent set of data, which is well suited for studies of radio spectra.