Radio age (May 1922-Dec 1923)

RADIO AGE— "THE MAGAZINE OF THE HOUR" Hookups and How^ to Read Them By Felix Anderson Radio 9 D Q S THERE is probably no more disconcerting incident in the career of an embryo BCL than the fact that with his initiation into the radio game he is expected to be able to understand a great many symbols, signs and diagrams. Usually, when he casually asks for information on the construction and wiring of a set, he is presented with a circuit diagram, more commonly dubbed "hookup," which to him is a meaningless lot of syinbols and signs on a piece of paper, which may be about as clear as a lot of Egyptian heiroglyphics would be to the average enthusiast who has become familiar with the reading and execution of the circuit diagrams. No doubt there would be less confusion and trouble in hooking up sets, if working drawings were used to portray different circuits. Each set is usually hooked up in an individual manner, and should error occur, there is a great deal of time and trouble expended in locating the error or incorrect connection. A radio expert will very seldom evince much interest in the set you are using, if you show him a photograph of the layout and ask him to point out your error ; but show him a concise diagram of the circuit, as you have connected it, using the correct symbols, and you will immediately notice a change in his attitude, and also the ease and quickness with which he detects faulty construction. The advantages of using a system of signs and symbols for portraying our ideas in connecting up sets and showing various circuits is readily seen. With the idea of admitting the newcomer into the mysteries of the radio pastime, the writer has compiled a chart of symbols which are used commonly in the course of construction, correction and design of present day radio systems. It is hoped that the reader will look over them, and should the occasion arise, make use of them in his queries and suggestions. Starting in the upper left-hand corner of the page of symbols, the conventional symbol for the antenna is shown. The symbol does not limit the size, type or kind of antenna in the least; it is merely used to designate that an antenna is used in a circuit, and its relation to other parts of the radio systeiri. The same applies to the ground, which is Lofty tower of the famous Station WJZ in its new home on Forty-second street. New York, between Fifth and Sixth Avenue. (U&U Foto). represented by a heavy bar, with several lighter lines underlying. Each symbol seems to suggest its own interpretation, much as does Indian writing. In the case of the ground, the ground symbol pictured gives the impression of the black bar being the top soil and the underlying lines a sort of cross section of the underlying soil. A counterpoise system is next symbolized. The counterpoise, although heretofore exclusively used for transmitting purposes, is rapidly gaining in favor wiih fans who find that the ground connections they are accustomed to use are inefficient and are poor conductors. It is merely another antenna system, similar to the one used as the receptor, connected to the set in lieu of the ground. The symbol of the loop antenna is next shown. Connections are made to the free ends of the wires as indicated in the illustration. Referring to the illustration of the two-slide tuning coil, it is easily explained that a coil of wire us usually indicated in a diagram by the use of a series of loops in a continuous string. This coil is also called an inductance. The two arrows indicate that there are two sliding or similar arrangements, which provide a means for increasing or decreasing the number of turns used in the circuit. This variation can be accomplished either by the use of sliders or taps. Sometimes a tapped inductance is indicated as in the symbol for the tapped coil. The type of circuit, and the design of the set govern the use of either taps or sliders. Connections of wires and instruments are usually indicated by a dot, and the non-connection where lines cross each other in a circuit diagram is indicated by a small hump, inferring that the wire is jumped and not joined. Binding posts where designated are indicated by a small circle. Batteries, of all voltages and types, are usually shown by the use of a long light line, followed by a shorter, heavier line, running immediately parallel to each other. The long line should be marked plus or positive, while the shorter, heavier line is termed the minus or negative. A choke coil, commonly used by the average enthusiast, is designated by a series of parallel lines, encircled by a series of lines indicating the wire, the parallel lines showing that a core of soft iron was used, around which the wire is wound. • The variocoupler or loose coupler is probably one of the inost widely used and most popular forms of tun