Wire Line Systems for National Broadcasting

HAT we are here considering, as an important factor in promoting national solidarity, is the tying together of a whole nation so that a single broadcast will instantly reach even the most remote points. Radio broadcasting stations (employing the more generally used frequencies) are essentially local distribution centers serving effectively points up to 50 miles (80 kilometers) or, in favorable cases, 100 miles (160 kilometers) or more from the radio transmitter. For the larger nations it is evidently necessary to make division into areas, locating a radio transmitter in each area for its coverage, and then to provide a network of circuits connecting the transmitters in the various areas with the point at which the broadcast originates. At the present time wire telephone systems are employed almost exclusively for this national distribution of broadcasts. It is the purpose of this paper to discuss the wire networks which are now being provided in the United States by the Bell Telephone System. In the United States at the present time (January 15, 1929) programs are being regularly distributed over extensive wire networks or " c h a i n s " as indicated on the map of Fig. I.2 The various chains 1 Presented before the World Engineering Congress at Tokio, J a p a n , October, 1029, Proc. of the I. R. E . , November, 1929. 2 This m a p has been revised to show the network chains as of September 1, 1929. 141 10 W 142 BELL SYSTEM TECHNICAL JOURNAL are usually referred to by colors and are so designated on the map.