Show A short wave receivers used for the reception ut short wave signals generally make use of a regenerative detector followed by one or two stages of audio frequency amplification in the majority of cases r t amplification Is not resorted to the reason being that the ue of r f etalea leconus veri for the hagli frequencies involved in the broadcast Brond cast lagi zine however Is described by george T I 1 itz jr a wave receiver efficient and easy to this re celver was first tried out just a year ago and has since been developed to that stage where it im be duplicated by the average set constructor with out feir of anaf snags cropping up it employs two stages of r f amplification the used for the reception of short waves differs some whit from that used foi the recep alon of broadcasting although of course the general theory Is identical the method of reception consists of tuning to the in coming frequency beating with it an other frequency anil then amplifying end detecting the belt note ahe ic signal listened to has in it none of the original frequency or the frequency which caused the boat note in the reception of broadcast pro gruna or other signals between 1 and kc and BOO meters the beat note selected Is a frequency somewhere between 30 and SO kilocycles kilo cycles this relatively high frequency Is selected to prevent the introduction of alstor tion by elimination of the sideband side band frequencies in the intermediate am tr and filter reception of short waves in alie reception of short wares pir the reception of c w this element of distortion anny be disregarded and bubli lias been the case in this receiver alie assumption being thit most of the will be c v ahe ordinary used for broida reception ins two tun ings ant the loop or antonni circuit second oscillator circuit this ahoi t w iv e super has only one tun ing arrangement in which Is corn honeil both alie tuning andl above this method of tuning was selected becque of its and because it makes possible alie construction of whit Is practically a single control ct alie intermediate frequency chosen Is 22 kilocycles kilo cycles which while too low i frequency for telephone alon when simple tuned circuits arc used Is satisfactory tor c vv or tele graph signals the selection of this frequency necessitates the set 22 kil cycle from the incoming signal but at the ro re to wave lengths of mateis or under this Is of no importance in decreasing signal strength I 1 ho reidar vw the description neove as applying to alie or type of super alie beat note of 22 kc 1 created in the tame as in the bronac it set nit at a loer frequency or the of short wave ne signals the glnn and detection of the 22 kc bent note Is in alie usual manner lien vv aln ils are to be received an other beat note must bp created either by me ins of another oscillator tube or by a he it note in tin twoie detector rulx the lat ter method has been selected a beit acte of 1000 leng hown aa the buos this of the ond circuit while it my to bo inefficient if the low altu mediate IS not so 1 nd a it H nie ni e the am in alie intermediate circuit Is verv treat there li pleno of lo 10 spurt two variable condensers in lc accompanying dia two arp shown but all the tuning Is awe with tilt one in die gril alie er in the elitc b set for enli bind of towered tor latance ln tance from kt to CO kc 10 to r mears kc to a rw k 45 to 0 att tills Is not alt nl IP alv Is thit the ault but lot so alo kintly tint it bawks the fond mtr across alie fec frari in alic Ir cult Is not d a I 1 the choke coll consists of turns on a wooden form 1 inch hii and 2 inches long cona or similar coll of IO 10 or 0 turns hlll also berye yen alie mers must tw of alie rather tow v of 23 kt in ibis st t those d ly alie Sp vera used but are uni of others alil ive la 11 than ald abid plate are made by winding hire copper wire of no 16 gauge over a form on which are placed four narrow trips ot celluloid squally spaced I 1 he wire Is paced string and when completely the string Is removed and the ivare cemented to alie strips by means of liquid celluloid the construction of this type of coll Is to any A one who has followed the development of the wave regenerative re tha cois the diameter of the colls Is 3 indies for winter er band the colt Is designed to cover in the alado article details are given for mal ing colls for the 40 50 anif 0 meter band in the first detector clr cult for forty meters the antenna coll his six turns the grid coil seven teen turns with tap at lie fourth turn from the filament end and the plate coll three turns the figures given i for the coils are kiil approximately correct as the method of wiring i mounting etc all affect the capacity of he colls and n consequence tho number of turns od to cover a given frequency range here the operator or constructor has a satisfactory ne belver already in operation there fa no need to change even though tt circuit differs from the one shown 1 I he only requirement Is that the primary of the intermediate trails former oe free of a capacity shunt greater than mad the filter circuit which precedes alie second detector tube Is of special design ahe coll consists of turns of alro on i 1 inch spool the secondary of 2032 turns on a cafe inch spool the tickler of 1 turpi on a 1 luch spool 0 o 32 cl s c win Is employed the spacing between these throe colls should be varied until best results are obtained it be about 1 between tickler and secondary and 1 inch between secondary and primary auto batteries are not suited for radio tubes man people who automobile batteries of the regular six volt type to light the tubes in their radio sets notice that a charge does not seem to last long and that the batteries are continually running down they arc especially puzzled be cause these batteries usually have a rated capacity of ampere hours which should he sufficient to insure fit least two weeks of service without charging alie trouble Is due to the fact that batteries ire not designed for use 11 ey aro constructed art supply a heavy rush of current for a short time to turn the engine over a deiv times before the T starts work radio sets n ehll amount of carrete over a comparatively fong period lien an automobile battery Is eo for lighting the nt radio tubes the places are not antl worked and the active chemical in id rials tue plates take on n state of stagnation evvs ahe charge and adte harge rate for an battery Is err high dease d ease we of both and n alie radio set awner Is adelel adv lel tp linte a storage having a of CO or SO ampere hour being blk enough for even he largest insulated wires prove best for the aerials alrea may he eltar 0 not th Is upon the of ilni and not upon th reception bare copper wire 0 o 14 lias hf en extensively for amateur at rials this is lj satisfactory evlion new hut as it soon becomes corroded from exposure to be it Is in the long inn Ii ophor bronze Is romp almea aed but this lins a rottier liegl ganv have beair Inwall lna made of the weather proofed insulated wires us d for long distance hues isac selecting tubo sockets t tube hould bp made of tha apt of insulation ni antl the should be st an of tint proper contact he at nil times with lip ulo prongs these are important points s t mattry voltage the battery should elways b above oce half full bharga while n and C batteries should tx drop to tow clr normal |