THE KICK-OFF

Evening Post, Volume CIV, Issue 24, 28 July 1927, Page 18

THE KICK-OFF

Now that powerful broadcasting is available over a largo area, tho crystal receiver has come again into its own in this district, and a great revival of home-construction is already in full swing. Although there is something to be said for tho easo and satisfaction ot going to a shop, buying a receiver, and knowing that there will bo no further trouble, • tho real fun of crystal reception is in making the sot at home, it is a very oasy undertaking, and the enthusiast can remain happy for weeks and even months, oneo the "bug" has bitten him properly. The first receiver for a powerful local broadcasting station is a very simple affair, and is quite satisfactory even it it is not very well made. It is not likely to be, but if it is a rough one it will spur the maker to do better. Ino first requisite is a coil of wire i'or ease of construction this can be made by winding about fifty turns of enamelled wire tightly round a cylinder of dry cardboard, ebonite, or some other former. Tho turns may be close together or spaced apart by winding a hno string on at tho same timo and unwinding the string later. Spaced winding must bo tight. Tho ends are iixod by lacing them through two or three holes. This coil should bo iixod m some convenient way upon a board and a "slider" rigged to make a sliding contact across tho wires. This can lie a swinging arm of metal, or a strip of metal iixod parallel to the surface of tho coil and carrying a sliding contact piece. One end of the coil is connected to tho slider and also to an "cart" terminal. The other end of the coil is connected with a crystal "detector and also with an aerial "terminal. A pair of telephones is then connected between tho crystal detector and the earth terminal. That is "all there is in

tho receiver. The detector may be made or bought, and ssmo excellent ready-made crystal detectors can be bought very cheaply. An aerial is, of- course, required, and a lead must be taken to a suitable |'earth," which in the majority of cases is the water-pipe. In the city a small aerial will bring 2YA in quite* strongly, and the first fine frenzy can be assuaged by using a few yards of wire draped gracefully along the ceiling round the walls. But do not bo tempted to tie it to the electric lighting fixtures. Having started, to wind the coil, stop. Go and get the license before finishing.