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Show I HOW TO MAKE A SOUND INTENSIF1ER The Assembled Intensifier, Showing Parti; Can Be Made From Discarded Reflector Re-flector of Automobile Light. The pork packer is said to mpke use of every part of a hog except the squeal and the curl in his tail. Some of the radio experimenters make use of t'.e squeal. The following describes a useful piece of apparatus for the radio amateur, ama-teur, constructed at a low cost. All the material can be readily procured for practically nothing at some motor rtrage. At a friend's garage and In the junk box was discovered a discarded front light reflector from an automobile, an old aluminum commutator from It, a broken rubber bulb from a motor horn and some motorcycle spokes with nipples nip-ples attached. These were obtained free of cost and brought home. The first procedure was to clean off all grease from the reflector. The flat flange at the broad end of the reflector was next cut off and the surface made smooth. This left the two beads on the edge as the finish. The hole in the center cen-ter of the reflector, through which the socket of the lamp passed, had a small flat disk of copper soldered In. The re- r r DISC SOLDERED ON H3-J -- HOLES FOR SPOKE Transforming the Reflector. Sector was next polished inside and silver sil-ver plated, and the outside was enameled enam-eled black. Four holes were drilled equidistant through the reflector edge, Into which holes the spokes fitted. This finished the reflector (see Diagram No. 1). The commutator was taken apart and the aluminum shell cleaned, and then the lug was cut off. The oiler was next removed and the hole from which it was taken was countersunk inside and outside, and in tills hole a plug of soft aluminum was fitted and riveted over so as to fill up the hole. All roughness, rough-ness, both outside and Inside, was removed re-moved with a file and scraper. A block of wood was then turned on the lathe to fit Into the broad end of commutator commuta-tor casing. The outside of the commutator commu-tator was turned smooth and a hole bored In the end of the cone; this was turned out, leaving a thin tube projecting. project-ing. Four equidistant holes were bored near the broad end of the cone on the flat surface of the commutator, Into which the spoke nipples fitted and were countersunk on the Inside to suit the heads of the spoke nipples and these were filed flat, so that when In place the surface inside the commutator commuta-tor shell would be smooth. Four equidistant equi-distant holes were bored one-quarter of an inch from the flat edge of the shell (to take four small screws) and countersunk coun-tersunk on the outside. The nipples were removed from the old spokes and were cleaned and polished. pol-ished. The spokes were cut off exactly inches long from the threaded end ; a small washer wag fitted on the other end and the end of spoke riveted over and the two sweated together neatly. They were then copper-plated and silvered, sil-vered, like the reflector ; four spokes were required (see Dagram No. 8). Next a strip of stout sheet brass was rut, as Bhown, and holes were bored for icrews. A large hole was made to take B-botes fir smv nippta j4 J if Ma frxm uLH -4- -3- the projection of the reflector, to which it was soldered when assembled (see Diagram No. 4). The old horn bulb wag cleaned well with gasoline and was left ready to cut to the proper length when the complete ap7aratus was ready to assemble. See Diagram No. 5 for sketch of apparatus ap-paratus when assembled ; the letters Indicate In-dicate the various pins. A. Screws holding wooden block and commutator shell together. B. Nipples of spokes holding commutator com-mutator shell central with reflector. C. Spokes passing through reflector reflec-tor and commutator shell. D. Earpiece of telephone receiver. E. Piece of rubber bulb as sound deflector conveyor to reflector. F. Commutator shell. G. Wooilen block fitted Into commutator com-mutator shell. In which telephone Is fitted. II. Adjusting screw to press receiver re-ceiver azahst rubber washer M. J. Holes for waves from telephone receiver. K. Holding down clip for fron of reflector. L. Brass standard screwed to base and soldered to reflector. M. Rubber ring made from inner tube of motor tire. The arrangement for using the old aluminum commutator shell for holding hold-ing the telephone receiver can also be applied In a different manner. If the wooden block Is turned flat It could be screwed to the top of the radio cabinet and a large horn fitted on the small end of the commutator shell as amplifier. If a number of holes wero drilled in the side of the cone and the holes tapped to take ?i-inch brass pipe, It could then be fitted with rubber tubes, which could be fitted with earpieces ear-pieces of glass tubing and used by a number of persons. Part of the brass knob taken from a bed or a door could be used instead of rubber. Procure a telephone receiver, the diameter di-ameter of the cover of which Is less than that of the Inside of a commutator commu-tator shell which Is two and thlrteen-sixteeuths thlrteen-sixteeuths Inches. The depth from the face of the earpiece to the back of the telephone does not matter much, as a wooden case must now be made to fit Inside of the commutator shell ; In this wooden case, part is turned out to hold the rest of the receiver. A rubber rub-ber ring Is put Inside the commutator shell and the earpiece rests against It. The wooden case Is then put In place and with the commutator shell It la held firmly by four screws. An adjusting ad-justing screw at the end of the wooden wood-en case presses the earpiece tightly tight-ly against the rubber ring and makes an airtight joint. The connections can be brought out through the wooden case of flexible cable, or otherwise, to suit the maker. Diagrams of each part are shown, as well as of the assembled as-sembled Instrument. When all parts are ready, proceed to assemble as follows fol-lows : Take commutator shell reflector and four spokes; pass a spoke from the outside of the reflector Into a hole In the commutator shell and screw on the nipple; do the same with the other spokes. The shell Is then held In the center of the reflector with the narrow nar-row end pointing towards the polished face of the reflector. Tighten up the nipples evenly until the shell Is rigid, with no wabble or shake. The piece of rubber horn bulb Is cut so that there Is a space between It and the face of the reflector when slipped over the end of the commutator shell opening. open-ing. The brass strip Is slipped on the outside and fastened to a neat wooden base. The edge of the reflector reflect-or rests on the wooden base and Is held down tight by a screw and clip. When the reflector Is fixed on the baso, the brass strip can be soldered to the back of the reflector. When the telephones tele-phones are Inserted, the block placed In position, screwed tight and the back adjusting screw tightened up, all is then complete to connect up to the set. ( Science and Invention and Radio Newa.) |