Abstract
DEMONSTRATIONS have recently been made of the broadcasting of messages over the electric light and power mains. In 1927 the method was conceived by Captain P. P. Eckersley, who, at that time, thought that the B.B.C. should deal with this special transmission. There is no technical defect in the method. For example, a message can be sent from any substation to all the consumers with which it is connected. The messages traverse one of the underground mains and got back to earth by a leakage circuit which contains the signalling device. This system has the advantage that it can be applied very readily. It needs no overhead wiring and so is less vulnerable to attack during a war. It could reach the nine million people in Great Britain who are supplied by a company with electric lighting in their homes. If domestic telephones were used, only two million homes would be available. The following objection to the method has been urged by some engineers. It is said that in time of war or civil commotion, enemy agents could easily inject messages into a power mains system and that it would be difficult to locate where they were working until the mischief had been done. Similarly, they might be able to jam any official message to the public. Seeing that power networks are sectionalized it is improbable that pirate messages would reach more than two or three hundred people at most. If a telephone service were used the number of listeners affected would be about the same as with the power mains system. In either case it would not be difficult to devise a method of locating and cutting off the offender. Electric supply engineers are quite enthusiastic about the broadcasting method. Captain Eckersley and Mr. W. B. Woodhouse are urging that a conference of all bodies interested should be called in order to decide, without further delay, what is best to be done.
Article PDF
Rights and permissions
About this article
Cite this article
Broadcasting over the Power Mains. Nature 144, 361 (1939). https://doi.org/10.1038/144361c0
Issue Date:
DOI: https://doi.org/10.1038/144361c0