Amplifiers (3), low noise, field effect transistor, cryogenic, for the Australia Telescope, metal/plastic, CSIRO Division of Radiophysics, Australia, 1984-1988
Three amplifiers for different wavelengths, (-1) 20cm, (-2)6cm & (-3)3cm, in flat metal boxes with top covers removed and replaced by perspex for the 3cm and 20cm amplifiers. Amplifiers are constructed with transistors, circuit boards and other electronics. There are input and output sockets on the edges of the boxes. In use the amplifiers are used cooled to -253 degrees C, a much lower temperature than could be achieved with ordinary transistors (not field effect transistors).