Show CRYSTAL DETECTOR EASY TO CH CONSTRUCT telephone Condon condenser ser and receivers rei can better flatter be he purchased I 1 howting Moun the set the th material needed to construct a staple simple crystal detector Is ax follows piece of silicon or galena molded in a metal metat button 25 conta cents two binding poets posts 20 cents A block of shellacked or stained wood S 21 by 8 I 1 A hin thin strip of copper or brass laches wide by two inch inches long mount the two binding posts on the block of wood as shown fastening fasten lne under one binding pont post n strip of ropper copper or brass see sketch and under the tho other binding post a colled up spring of fine springy copper or brans brass wire dy by placing the button of metal con 1 ments the tuner the cryltal detector aad and tm th telephone condenser ain be mounted on a stained base of wood eny my eight laches inches quart and oo one haf half tach inch thick thi this will loop leep the coin parta of the set et together tank ins ing R compact unit of tho the whole and also be advantageous in that it will bold hold tho the instruments while adjust ments are being elude nude the ketch sketch ahoe how the instruments arc are connected with each eack other ned and to tho the ground the condenser 3 connected to one elde aide of the tuner and nd to the crystal detector the gro round nd ie is connected to tho the other eldo aide of the phobea ones aad and tho the condenser and the tuner lamp cord to excellent for connect ing up email small radio bets sets of this kind it being a good conductor well ingv and easy to handle HOW TO LISTEN IN there are two variables la in our radio receiver that require adjustment when it la Is desired to listen arst the detector and second the elide slide position on the t tuners un er once the allder slider position hae has been determined for any given transmitting station it ii to oaly only necessary nece seary to adjust the detector to pick dick up that samo same station again to operate the re receiver celver for the first time it Is in best beat to wait until so some me station liko like Is transmitting be neen and p V m then ad ada OV hip a 30 4 4 pori the crystal detector TUNER around por J set mounted on base with connections shown kalning tal ning tho the crystal of silicon or galena on the strip of metal nod and allowing the spring to make contact with ith the surface of the crystal the detector Is complete and ready for operation A complete crystal detector can be purchased from 75 cents to 2 depending upon the type two other pieces of apparatus are necessary that cannot be readily constructed ted they are the telephone condenser and the receivers A telephone condenser to be used in shunting across the phones can be purchased for about 60 50 cents for usa with a radio receiver of this type it Is recommended that a pair of ohm murdoch type no 50 receivers costing 0 be purchased these are all the necessary parts needed for the complete receiver if it Is desired the three inspru just the detector by chancing changing the point at which the spring and crystal of the detector make contact knur when a nearby electric light Is snapped on and oft off a click Is heard in the head phones the detector Is in now adjusted on a sensitive spot oa on the crystal by changing the slider po tho the transmitting station should bo be picked up after a station Is once picked up it Is an easy matter to adjust the detector te etor and slider position until maximum response Is obtained tn in the tel ephone receiver with a simple set of the kind described in this and preceding articles and a little practice one soon becomes adept at picking up a given station the entertainment derived from li is usually well worth the me time uwe spent and the money invested |