Engineering and planning of a radio broadcast facility

Abstract

The radio spectrum is a resource which unlike other resources, is not consumed - it is being wasted when not being used. Effective management of this valuable resource is necessary because of the limited number of channels that are physically available for use.

Without regulation, stations operating on the same channel in the same general area will inevitably interfere with each other and often also with others on adjacent channels. Therefore, the Federal Communications Commission (FCC) regulates the use of this national resource in accordance with rules which have been developed and continue to evolve. These rules relate to all kinds of broadcast services including AM & FM radio and TV.

In defining the technical specifications of a new broadcast facility, the engineer must try to achieve an optimum system design while conforming to all FCC rules and regulations. The design process is divided into a number of stages which include channel and frequency selection, site selection, protection and interference studies, topographic studies, and an environmental impact statement considering the area in the vicinity of the facilities. These specifications must then be submitted to the FCC as a formal proposal.

This report describes the design approach used in industry to specify the technical details of such a proposal and highlights the tradeoffs which are made at almost every stage of the process. The hardware needed to implement the technical details specified must be selected. Various types and configurations of transmitter-antenna systems and tower configurations are evaluated and an optimum design is sought.