Show THE BOME HOME E RADIO how to make and use it czap sp by A HYATT by VERRILL A XV VARIO COUPLERS AND VARIO METERS vario couplers may also lie be home ionic made it II fl do dodril drol but they are seldom very efficient A arid and are i or is they ory cry al fo low in price it Is 7 so scarcely arcely worth while C A to attempt their manufacture these consist ot of two colls coll sone one rotating within tho the other lf if desired to malse a varlo coupler you will require a cardboard tube or ft a fabre fibre about four and ona one half inches in c C diameter aud and five indies inches long A rotor ro t or form that may bo be purchased tor for a dollar or so of no 0 O M 20 aud and no 28 11 S gauge double cotton rr ff covered magnet wire A and some no 20 of tile the same type wire IW you will also require ZI P r sa I 1 a brass shaft or cr rod 24 inch diameter a 01 0 var 1 as dial knobs awit switch oil a panel of fabre fibre or bakelite bak elitc elito about 3 16 inch thick and 6 inches square and a wooden or fibre fabre base 2 inch thick and 6 inches square besides screws odds and ends etc the cardboard tube and rotor form ire are preferably soaked in para frine but tills this is not essential begin winding the cardboard tube starting 31 inch from one end through a smell hole as shown aud and AN wind ind on 33 turns of tile the no ag ire keeping the turns close together but not touching then bring the wire iacross across the tube as shown in F fig ig 37 leaving a space of ne me inch hare bare and f continue to wind on another 30 turns of wire nire in gindin winding take oft ahree ahr ee taps fro from e each ach section one at every twelve turns beginning nt at turn from top find and leaving two bumaat bottom of winding ns as shown in alq fl 37 T T T finally passing the edd cod through a h lole hole ns as shown the whole should then be covered with rg raffine or it may be shellacked shel lacked although shellac will decrease its efficiency and will serve every purpose in the center at the bare space which has been left a 1 J inch hole should be bored as ae shown in the cut the next dext step Is to wind the rotor form which Is done by winding on turns of no 20 wire starting through a fine hole as shown which forms the tickler coll coil fig SS 33 A and leaving the two ends of the th wire about 6 inches long and running the I last end through a hole to hold ft 41 vien ilen at the other end of ill the c ro rotor t 0 OV wind wina on forty two turns of no ai to form the secondary fig 38 r D tad leaving free ends of wire about G belics ion long through tile the center of t rotor form a hole should be li it i rd ed inch tn in diame diameter as shown lie he next dext step Is to tn mount alint the amiller iiii which Is done as follows an fn r the fibre fabre panel bore a 14 inch hole bole t 1 i inches from the top and ties hes from one side fig 39 in li it lower corner place a switch with x contact points A and on the right hand side drill six 3 10 16 inch holes fr binding posta posts B then malse make and place the shaft in the rotor securing it by glue sealing wax was or by mains of nuts according to your me hanl cal ability and attach the two parts to the panel fitting a dial and knob to shaft and mounting tile the panel on the base in connecting up tile primary secondary and tickler wires vires are connected to the six binding posts and the tha six gnp offs as on w the primary coll coil are connector connected to the switch contacts ns as shown in the cut with one of tile the primary wires in the switch post then when the coupler is to be sot set up tip the lie aerial Is connected to one of the primary posts the ground to the other tile the secondary posts are connected with the grid circuit and tile the tickler posts to the plate and receiver beiver circuits all of which Is shown in the diagram fig 40 A may he made in a very similar manner using two cardboard tubes one about four inches in diameter and three inches long the other three inches long and about throe three and three quarters inches in diameter the dimensions should be such that the small tube can turn freely without touching within the larger tube and the smaller the space between the two the better but you must remember to allow for the thickness of the wire win to be wound upon I 1 the inner tube first measure mease re carefully the exact centers so BO that when a shaft fastened to the inner tube or I 1 rotor Is passed through the larger tube anbe the inner one will rotate freely and evenly without touching or increasing the space the entire efficiency of the varl ometer depends very largely upon the accuracy with chicly this Is lone done starting with a small hole about ia inch from the outer odge ot of the s smaller mallor 1 tube wind on about twenty tn turns ns of no 21 double coated cotton insulated copper wire bein careful to keep haep diw turns separated separate then skip ship a spi spice of abdat an inch as eho ebann n in F fig cl it and wind on an another twenty tn turns tn uneuy an auy ru running the wire through a liole hole both ends with A drop of glue or jo 11 ing was and leaving jive five or six inches of free wire at each cich on ani Start starting ln the same way wind the larger tuto tuta jn exactly the same manner and being burr to wind in III the same direction when all are wound mount the smaller tube ou on a shaft inside of the larger tube fastening shaft by glue or sealing wax dropped on from inside and mount as awn jt wv in n fig 42 finally connect one end of it wire to one end of the rotor ajr leaving plenty of free wire to allow to 0 revolve and lend the other two ends to binding posts post as shown being surp sure to keep tint to the rotor loose to allow free movement the shaft to rotor should be eq eini nipped ped with knob and dial as shown lii IN 04 gut cut and the whole mounted on a filere alre ar w panel on a proper base |