Radio Broadcast (May-Oct 1922)

10 RADIO BROADCAST set. It is the purpose of the receiving set to convert the radio energy into some form of energy which comes within the scope of our senses. In the case of transatlantic radio stations, photographic recorders are sometimes employed, so that the waves make their presence known by a wavy line on a band of paper. But in most commercial and amateur receiving stations the waves are converted into sound SMALL IN STATURE BUT NOT IN ENJOYMENT Three youngsters of Morrisville, Pa. listening to a concert and heard through the medium of telephone receivers or a loud-soeaking horn. If the waves are merely modified into short and long impulses, then we have mere dots and dashes of the telegraph code. Each letter is then represented by a certain combination of dots and dashes, the messages being spelled out letter by letter and word by word, except for certain abbreviations. If, on the other hand, the waves are modulated or moulded, so to speak, with the characteristics of certain sounds, such as the human voice or music, then the resultant waves carry inherent sound char acteristics which are reproduced in the telephone receivers of the receiving set, instead of the short and long buzzes of the radio telegraph waves. SHORTCOMINGS OF THE ELECTRIC ARC ANY one who has had an opportunity of studying the electric arc even superficially must have noted how erratic are its functions. Who does not remember the electric arc lights formerly used in highway and street illumination? These lamps would sputter and flicker almost incessantly. The arc light of a motion picture projector generally kicks up a fuss every so often, causing a change of intensity on the screen. And when these irregularities are coupled up with such a delicate thing as the generation of radio waves, their action is amplified ten thousand fold or more. At any rate, the pioneers in wireless telephony had the arc to work with. It was to be their generator of radio waves, although one or two workers had constructed special alternating current generators capable of supplying current of very high frequency. It was the good fortune of the writer to participate in wireless telephony back in 1908 and 1909, with a transmitter of German make. It was a huge affair, about the size of an overgrown upright piano, with a table in front and a tall switchboard at the rear. A series of experiments was being conducted for the United States Signal Corps, with a view to proving the practicability of radio telephony in military communication. The distance to be spanned was some 18 m.iles, or the air line between Fort Hancock, Sandy Hook, and Fort Wood, Bedloes Island, in the very shadow of the Statue of Liberty overlooking New York Harbor. The high hills of Staten Island intervened, making communication between the two points all the more difficult. By a queer turn of fortune the receiving station was located in the very same radio station building that is now being employed by the Signal Corps for a radio-phone broadcasting station. The main difference is, however, that the present installation works; ours didn't! Needless to bore the reader with an elaborate description of our pioneer radio telephone. Suffice it to state that it consisted of ten arcs, each arc made up of a copper cylinder closed at the bottom and filled with water so that it wouldn't melt, as well as a large carbon button (