Radio Broadcast (May-Oct 1922)

466 Radio Broadcast CAPTAIN MAXSOn's LOOP Before the use of the radio compass became general, Capt. Maxson of the S. S. Monms built his own radio compass with which he made many interesting observations Although the radio direction finder was given some scientific consideration before the war and did manage to find itself on one or two vessels, it was thought to be a refinement more costly than valuable. Little attention was paid to it in other than government shipping circles and the only improvements made were of a scientific rather than a practical nature. When the war god drew his sabre and the brains of the world concentrated upon the means to win back peace, it was natural that scientific devices which could be used would be immediately developed. Radio engineers, here and abroad, strove to perfect the radio compass, because it assisted them in locating enemy troops by determining the direction of signals coming from the latter's radio stations. Many other applications of the compass were evolved and put into practice, especially in connection with the guiding of bombing airplanes on night errands. The radio compass was also used on some of our transports and other fighting craft for locating hostile submarines, as well as for general navigation. It was developed to a point of comparative practicability before the end of the war, and since that time it has been the direct means of averting many marine disasters. Much of the work done in perfecting the radio compass could not have been successful without the development of the vacuum tube, which it made possible more accurate observation over greatly increased distances, than was possible with the older types of equipment. RADIO COMPASSES AND BEACONS THERE are two distinct methods for the application of the radio compass idea, for guiding vessels in foggy weather or for any of the other maritime uses to which it may be put. Our Navy Department and our Bureau of Lighthouses have contributed much to the perfecting of a system for guiding ships when all other forms of navigation would be valueless. The radio compass, in the form most common in this country, consists of several turns of wire wound on some sort of a frame which may be orientated by a handle or other device, coupled to the proper tuning apparatus. As the coil is rotated, the operator can notice a marked increase in the signal strength from a given station, at a given point on the scale mounted below the handle of an indicating device. Where a magnetic compass is used in conjunction with this device it is possible to determine with only a slight error the direction from which the signals emanate. By emplo\'ing this system, vessels at sea can determine their bearing or direction from some receiving station on the coast whose latitude and longitude is known. It is not necessary for the ship itself to be equipped with a radio compass for the direction is determined at the shore station, where a compass coil is in operation, and the result is then sent by radio to the vessel. It is possible for a vessel to secure a very definite idea of its position, as well as its bearing from a given point. In this case, however, it is necessary to receive bearings from two shore stations located at different points. The point at which the bearings cross indicates the position of the vessel. Stations of this char