Wireless Telegraphy and Telephony

24 WIRELESS TELEGRAPHY higher than a flat-top aerial, in order to be of the same value. The “L” and “V” types are somewhat directional. They are used where the highest point must be near the station, with a lower point some distance away. It is possible to secure excellent results with either type. The terms straightaway and loop denote the method of connecting the aerial wires. In the first form the upper or free ends of the wires terminate at the insulators. In the Fig. 23.—Diagram showing the difference between “loop” and “straightaway” aerials. loop form they are all connected together, and divided into two sections, each of which is led separately into the operating room. The straightaway aerial is the most efficient in most cases, but wherever great height cannot be obtained, or the aerial is necessarily short, the loop aerial will give the best results. Bare copper wire is the best, and is generally used for aerials. Wherever the stretch is 100 feet or over, however, so that the wires are subjected to considerable strain from their own weight, phosphor bronze is used because of its greater tensile strength. Commercial and navy stations employ stranded wire. High frequency currents have the peculiar property of traveling near the surface of wires