Abstract: A satellite receiver which is capable of being connected to different antenna assemblies which require different operating voltages, includes a switch mode power supply which supplies the different operating voltages. A microprocessor controls the duty cycle of the switch mode power supply to produce the different operating voltages in accordance with the required duty cycle. A memory stores values which define different duty cycles for each of the operating voltages and provides the values to the microprocessor.

Abstract: A television receiver displays characters within a box on a display screen wherein the normal picture is also displayed within the box. Circuitry in the receiver permits a display of the normal picture within the box for viewing the total picture while achieving good visibility of the characters within the box. The circuitry provided reduces the contrast of the picture within the box in relation to the contrast outside the box.

Abstract: Interference induced amplitude changes in the television signals received by a receiver which receives satellite signals are eliminated by delaying the signals for an integer multiple of the receiver line time and substituting the delayed signals for the undelayed signals for the duration of the amplitude changes.

Abstract: Automatic switching circuitry for processing input signals of more than one frequency, incorporating information for the derivation of one or more audio channels. The circuitry, including a selectively variable bandpass device, may be one of several values corresponding to the frequency of a input signal. A demultiplexing device is provided to apply a demultiplexing operation on signals output from the bandpass device, with a control logic monitoring the demultiplexing device to determine if a demultiplexing operation has been achieved, and instructing the selection of another value for the bandpass device if no demultiplexing operation was achieved for a given value of the bandpass device.