Electrical Interference Aspects of Buried Electric Power and Telephone Lines

This paper discusses the audio frequency noise induced in telephone lines by nearby electric power circuits, particularly when the power and telephone companies employ joint buried construction methods. The electrical protection considerations of this type of construction are not included in this paper. Comparisons are made with the usual aerial type of joint construction. The factors controlling the amount of interference produced by inductive influence are described and evaluated. Recommendations are suggested for limiting this interference to acceptable levels for satisfactory telephone service.