The acceptance tests on the antenna and pedestal of the Helios command station

The acceptance tests are used to illustrate the complex relationship between the mechanics, control, and steering equipment (drives), and the radiation characteristics of the antenna. Coincidence of the mechanical and electrical axes at an elevation angle of 45 deg is achieved by adjusting the individual elements. The surface roughness of the main dish sets an upper limit to the frequency range. The maximum velocity and acceleration of the pedestal largely determines the field of application for space probes as well as earth satellites. The pointing accuracy and gain of the antenna have to be made compatible. Points which must be considered when preparing the specifications and acceptance tests of large steerable dish antennas are outlined, thus forming a work of reference for project engineers faced with such complex problems.