Radio Broadcast (May-Oct 1922)

ii6 PUDIO BROADCAST method of communication. Also since there is no radio interference caused by broadcasting on power lines, any number of wave channels may be employed and therefore multiplying the number of stations that can be operated on the same line. It is conceivable that in every community we may have several transmitting stations operating at the same time, but each on a different wave length and supplying different services; one might be used exclusively for music, another for current news, and still another for educational information, etc. Also by this means of broadcasting no antennae are required. A suitable plug connection in the light socket is all that will be required so that wherever the light circuits extend, which is nearly universal these days, radio broadcasting may be received. It is hard to realize at this moment the vast possibilities of this method of broadcasting, but judging from the universal interest in the preliminary announcement in the press, it is a fair guess that the system will come into general use very quickly. Wire Broadcasting By JOHN F. DUNCAN This article supplements the preceding one entitled "Broadcasting on Power Lines" by expanding still further the speculative possibilities suggested. — The Editor. WH EN a pleasant spring evening comes and you walk down to the public square to hear the first band concert of the season, probably you'll never think of broadcasting until the racket of some small boys makes you say under your breath, "Just like that spark station when I'm trying for KDKA." And then you suddenly realize that you are listening to broadcasting of the oldest known form — one which has existed since man first knew how to make intelligible sounds. For centuries sound waves in the air were the only means by which we could reach the ears of other people. Our message could be either person-to-person, or broadcasted to an audience, as we might choose. Then came the telephone, and one person could communicate with another, or with a selected few, even though they might be thousands of miles apart. Although the energies of telephone engineers were directed primarily toward individual communication, there have been several successful attempts at broadcasting by means of wire circuits. Two of these are interesting because they foreshadowed many of the radio developments of recent years. In Budapest a system was operated successfully for several years prior to the war, the subscribers of which could listen in at any time and hear a programme more or less appropriate to the time of day. Thus, current news would be "on tap" in the morning; market reports during the day; society news in the late afternoon; entertainment programmes in the evening. This service was furnished over copper wires tapped off for each subscriber's listening set, much like the long "party lines" in country districts. The expense was met by a monthly charge to each subscriber, and presumably the venture was profitable. In Wilmington, Delaware, the local telephone company about twelve years ago operated a "music" exchange, to which a telephone subscriber could be switched on request. Here were a number of phonographs equipped with telephone transmitters. The subscribers would give the title of the piece he wanted, and an operator would put on the record and start the machine. A charge for each record was made. If the person had no preference for a particular record, he was put on a "general" circuit which had a varied programme. A loudspeaking receiver with a horn could be rented for use at home, and a number were installed on a "pay station" basis at ice-cream parlors, restaurants, etc. For a time the system paid well, but eventually the general use of phonographs killed its market, and it was abandoned. With the addition of radio broadcasting we have examples of the three possible wa\ s by