The 100-meter radio telescope at Effelsberg

The 100-m fully steerable radio telescope of the Max-Planck-Institut für Radioastronomie (MPIfR) has now been in service for over a year. The telescope was designed to allow observations in the decimeter and centimeter wavelength regions, with the vastly improved resolution given by the 100-m diameter. During construction of the telescope measurements were made at a wavelength of 75 cm. Since the completion of the adjustments, tests and observations were made at 11-cm and 2.8-cm wavelengths. In particular, at the 2.8-cm wavelength, tests have fully confirmed the design goals. In fact, we hope to extend the operational range of the telescope at least to the wavelength of 1.2 cm. A number of problems, new in this field, had to be solved in the construction of an instrument of this size and precision. Measuring methods are described which allowed adjustment of the surface to ±1 mm. A computer-controlled servo loop allows setting of the telescope to 5". Experience of operation under various conditions is described.