31-cm radiometer for the RATAN-600 radiotelescope.

A radiometer employing transistorized amplifiers, for continuum observations at 31 cm, has been developed and is in routine daily use with the RATAN-600 radiotelescope. Stokes parameters, either I or U, Q, can be measured. The I measurement channel employs a single-beam arrangement with a noise pilot signal and gain modulation. The radiometer does not contain a separate modulator; the gain is modulated by varying the supply voltage of one of the amplifiers. The operating band of the radiometer is 900 - 1020 MHz; the equivalent noise temperature is 90K; and the equivalent noise temperature of the front-end amplifier is 55K. A modulation mode is used for polarization measurements.