Performance of a Cryogenic 3 MM Receiver on a 14 M Radio Telescope

A cooled receiver having a DSB noise temperature of 80-140 K in the frequency range 75-95 GHz has been built for radio astronomical observations. The quasioptical beam switch is followed by a 3 mm Schottky mixer and FET amplifier at 1.4 GHz. A phase locked LO is injected via waveguide and a ring-filter. This receiver has been tested in the laboratory and on the Metsahovi 13.7 m radio telescope.