The Australian 210-ft Radio Telescope

A steerable radio telescope 210 ft in diameter is under construction near Parkes in New South Wales. The instrument is intended primarily for research in radio astronomy and is expected to commence operations at the end of 1961. The paraboloid has an f/ D ratio of 0.41 and the surface error should be less than ± 9 mm under normal operating conditions. High aperture efficiency should therefore be realized at the hydrogen-line wavelength of 21 cm and the overall wavelength range should extend from metre wavelengths down to approximately 10 cm. The mounting is of the altazimuth type and its movement in equatorial co-ordinates is achieved by means of a unique master-equatorial control system. The overall pointing accuracy of the telescope is expected to be 1 minute of arc.