The dual channel 2390-MC traveling-wave maser

Reflected 2390-MC signals from the Echo I satellite were received by a horn-reflector antenna and amplified by solid state traveling-wave masers. This paper describes the design of the dual channel maser amplifiers for this experiment ∗ Each maser has sufficient gain (> 33 db) to override the noise of the following stage. Unconditional stability is obtained by the use of distributed ferrimagnetic isolator elements. Their instantaneous bandwidth is 13 mc, centered at 2390 mc. The effective input noise temperature is 8°K.