The development of TVRO systems

Some design concepts underlying the modern television receive only (TVRO) system developed specifically for CATV/LPTV operation are examined. In the TVRO system, the down-converter is normally an integral unit providing tuned and preselected 70 MHz IF out. The functions of the mixer, local oscillator, 1st IF, and 2nd conversion are contained in a single module. The receiver is a self-contained assembly including everything from LNA power supply to a television modulator in a single functional package. This allows fast replacement in case of failure, as well as an overall cost reduction. The cost of an average CATV satellite receiver is less than that of the phase locked oscillator used as a sub-assembly of a typical telecom receive link.