Radio Broadcast (May-Oct 1922)

258 Radio Broadcast friends in to hear a representative of the U. S. Government talking to them over the wireless telephone. They will not even have to know the code. The value of the information may not be understood by the boys themselves for a time, but go and get the president of the chamber of commerce in your town and tell him that you can supply him with information about the weather and food market conditions, received right from Washington and you won't have to do any more worrying about where the money is coming from to buy new wireless apparatus. The information will be worth enough to the community for it to buy your apparatus for you. If you don't think so, take this with you and ask your local Chamber of Commerce or Board of Trade what they think of the plan. So that is what Uncle Sam is doing, and from now on we will consider the least expensive method for obtaining satisfactory results in availing ourselves of these very great aids to the study of wireless telegraphy. OVERCOMING SOME OF THE DIFFICULTIES ONE of the greatest difficulties in connection with a wireless station, especially where it is not to be a permanent installation, is the arranging of the overhead wires, generally known as "aerial" or "antenna." Now, for use in connection with communication in stations which are to be permanent, it is very desirable to refer to some good authority on such matters and not go into the thing in a haphazard fashion.* But, where there is no possiblity of planning the station beforehand, which is generally the case when it is desired to communicate between two Troops of Boy Scouts in different parts of some woods, it is necessary to do whatever is possible and more or less trust to luck. For this reason we will consider two methods which have been tried with very great success, especially with portable sets. Of great importance is the erection of the aerial, so we will now consider it. The most suitable aerial for amateur portable field sets is, the single wire; that is, merely one wire in the air. There must also be a ground connection, but that is readily taken care of by driving a metal rod three or four feet into the ground or, better still, dropping it into water and attaching a wire to it, so we will confine ourselves to the aerial. On camping trips, it is generally advisable to be provided with plenty of copper *See page 2 14, also Radio Broadcast for May and June. wire for the making of several aerials, and it is also advisable to have several well-designed kites along, to be used as described later on. The first and most simple aerial is made in a few minutes and requires but one boy to get it in the air. If the troop is supplied with some stout twine and a few porcelain insulators, which may be had for a few cents, it is merely necessary to attach one insulator to the end of the string and then cast it, sling-fashion, over the top of any tree suitable for the purpose. When the insulator reaches the ground, on the opposite side of the tree, it is merely necessary to fasten a wire to it and pull in enough of the twine to raise the wire to a position about fifteen feet from the branches of the tree. The twine may then be fastened, and the wire may then be used for an aerial. Another very satisfactory method for raising an aerial is to fly a kite or several kites and run a wire up on the string. By using a suitable kite, such as the one described, it is possible to substitute copper wire for the kite string and fly the kite directly on wire, as is shown in the accompanying photographs. The kite string (wire) should be brought to an insulator before being connected to the set and the insulator should be fastened to the ground by means of a piece of cord or another piece of wire. MAKING THE KITE DURING the writer's boyhood, he was fortunate enough to have made the acquaintance of a man who was an expert on kites and kite flying, and a few tips upon the selection of the proper sort of kite for use in conjunction with a radio set as well as further tips concerning the making of such a kite from the figures of the kite expert himself will prove helpful. The kite shown in the illustrations was made according to the directions here given and proved entirely satisfactory. It is best to be sure that the wood used for the ticks is spruce. That both the upright and cross sticks are of the same length. That the cross stick crosses the upright stick at a point one-seventh the distance from top to bottom. That no nails be driven through or into either stick. That the proper method of holding the sticks in place is to wrap them securely together, so that they may be readily taken apart again and folded up for carrying purposes. That the vertical or upright stick be placed so as not to bend, but with its flat side at right angles to the kite cover. That