A Gain-Stabilized Maser Radiometer for 13 cm (Correspondence)

A radiometer using noise from a neon discharge tube to effect gain stabilization of a 13-cm maser radiometer is described. A balancing technique is used to make the output insensitive to gain and bandwidth fluctuations. The output does, however, depend on the total system noise temperature, and the technique is best suited to a receiver using a low-noise traveling wave maser, whose effective noise temperature is inherently stable.