Flux Measurements of Cassiopeia A and Cygnus A between 18.5 MC and 107 MC

Results of a series of measurements on the two most intense radio stars are given. Basic techniques for absolute and relative intensity measurements are described. Principal sources of error are discussed with special attention to the very controversial range below 30 mc. To minimize one common source of error, interferometer arrays using simple dipole antennas over reflecting screens were used for all absolute measurements of Cassiopeia A. For relative amplitude determinations, collinear arrays with higher resolution were employed. The absolute observations show flux densities which increase by a factor of two between 100 mc and 40-50 mc, and then continue a more gradual increase to 18.5 mc. The amplitude of Cygnus A relative to Cassiopeia A is between 0.5 and 0.6 over the entire range of frequencies.