Page:Popular Science Monthly Volume 91.djvu/333

 Wireless Work in Wartime-L

The beginning of a series which will cover every present-day application of the principles of wireless

By John L. Hogan, Jr.

��IN military and naval warfare there are many times when no man is of more importance than the radio operator. Upon his speed and accuracy, and on his knowledge of the principles of his appa- ratus, may depend the failure or success of great strategic moves. Radio amateurs and operators, as well as those who have an aptitude for this work and are now taking it up, are indeed fortunate in having the opportunity to serve the Nation so well in the present crisis. Radio operators are needed in the Sig- nal Corps of the Army and in several branches of the Naval service, including the new fleet of submarine chasers now being equipped. The call for men to take up these classes of military work will leave other positions open, particularly with the commercial radio or- ganizations, positions which probably can be effectively filled by competent women. There is and will con- tinue to be a demand for skillful wireless op- erators, both experienced and newly trained.

Fundamental Knowledge

The fundamental knowledge which all radio operators must possess relates to the use of the Continental or International Morse code. It is absolutely essential to be able to send well-formed Morse char- acters rapidly, and to have the ability to write clean "copy" when receiving signals from a distant station. Without this ability none can claim to be a radio oper- ator. And of only slightly less importance is the understanding of the basic principles of the apparatus used, together with the ability to adjust it quickly and accurately. This first article will take up the study of the code, pointing out not only the best and quickest way to learn it but also the elements which characterize good and bad sending. Just as many engineers fail to

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��appreciate what is going on inside their instruments, so many operators fail to realize that there are good reasons for a number of rules of sending which appear unimportant at first glance. Either atti- tude leads to results which must necessarily be poor when compared with what is attainable by a little careful study.

It has been stated as a general rule that men and women who have a feeling for musical rhythm make the best teleg- raphers. It seems curious that the same quality of beating time enters so strongly into both music and teleg- raphy. A keen time- sense, or the ability to note and correct small variations in time in- tervals, is of extreme importance to the tele- graph operator. This is because the tele- graph signals are sent by turning electric currents on and off for definite times. The elements of the Continental code are dots, dashes and spaces. Spaces of various lengths are merely periods of idleness, when no current is turned on. They occur between letters and between words, as well as in separating the dots and dashes which combine to form each character. The dot is the short active element, and is formed by turning the current on for a brief time; the dash is a longer active element, made by allowing the current to flow about three times as long as for a dot. Various combi- nations of dots and dashes stand for the various letters of the alphabet, and words in any language are spelled out letter by letter.

Learning Telegraphy

There are three steps in learning tele- graphy: viz., memorizing the code, manipu- lating the sending key, and writing out incoming messages (reading by sound). These are independent to some degree, but

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