Direct transmitting satellites for broadcasting television and sound programs

Procedures for broadcasting sound programs using a digital modulation method are discussed. A maximum of 15 digitalized stereo programs can be transmitted in each channel, with a signal-noise ratio of more than 60 dB. The electronics of the TV-SAT D3 payload is examined with emphasis on the semiconductor channel amplifier. A current supply apparatus for the travelling wave tube with over 90% efficiency is discussed, and a block diagram of a group satellite receiving installation is presented. A diagram illustrates the 11.7 to 12.5 GHz region which is divided into 40 radio frequency channels for television transmission by the European countries.