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Show Hon which would hum all single-tuner circuits te be dlecareed aa I'art I . . ' fP4 f my n. i duncan. Dlractor Kaolia Inailluta af Amarlta. 'hiri an outdpr aarlal cannot b aractad. olthar en aocemnt of lark ol fmrll-lllaa fmrll-lllaa or A dlaaaTaaavbla landlord, (ha radio anthualaol ahotild uaa A loop antoniiA. Thla eon. bo mado oaally and placad In a eornar of a room or al tic whara It would bo out of tho way. ralrly (ood raaulta I ara oblalnad by ualnc thla Indoor form of antanna, I Tha alaa of the loop aarial dapanda upon tho loratloo of tha ravalvlna; atatton. Ita dlatanca from tho broadcaatlns nation, ate. Iion't try to uaa a loop aarlal with a eryatal dotortor or alnala vacuum tnha racalvlno; aat unlaaa you ara vary naai tha traiiamlltlna: atatlon. At any dla- I tanra away ona ahould hava at loaat a datactor and (wo-atap amplifier. CONtTPHUCTION. I A (nod loop antmna fr raralvlraf wavo lanartha up to aao mat ara la ona alioin four fat aiiara. ualnc IfMir turna of l.ll londraht wtra apaj-ed ona-fourtk of aa llirh batwaan aa.h turn. Thaaa wlraa muat not touch, ovan thouah thay ba liiaulalod. Tha frama of tha loop may ha con-atructrd con-atructrd of two amall itlacra of wood croaaad at tha ranlar. Thay ahould bo a hula mora than a -l foal tons for tha four fat aquara kKm. Mine, tha loop haa a dirartlonal affect In reralvtna. tha frame ahould la mount, ad on a amall wooden uprurht, huh oan lio held In place by a aolid wooden "If. 1. Slnflla. tune Circuit. of the report reads: "It Is recommended that tha secretary of commerce, at his discretion, prohibit at any tlm the uae of exlallna; raHo re-ceivlna; re-ceivlna; apparatua which may causa the radiation of ee r try." This applies to the single-tuner circuit receiving sot. Another f ml liar name fot this set Is tha oscillating circuit sat. INQLB TUNIR. Huch a aat la con a true ted so that feMv radiations of continuous waves are emitted emit-ted throuRh tha aarlal while In tha proo-' proo-' ess of rcelvlng Huch radiations my causa ronalderabl loal Inierferenca in tha Ira nam ma Ion of m-aas;ea. An eian ie of ft slngia-tuner circuit la shown In Fig. 1. It may ba noted thai tha detector tub, which oscillates while receiving. Is directly connected to th aerial. Enenry Is transferred from th H battery through the secondary of tha v art orou pier to tha plate, then back through tha gild Into the aarlal. j The hook-up of this form of set Is: 1 Variable condenser. 2 Varlocou-plr; Varlocou-plr; I (Jrld lah and condenser; 4 !-tector !-tector tub; Mlament rheostat; A battery ; 7 B battery ; t Fled con - naer; t 1'honea shunted with flxeej ron denser. TMIVLK TUNIR. In th threa-tunar circuit, back radiation radia-tion la practically eliminated. This Is because best reoalvtna; results are obtained ob-tained by keeping tha detector tuba below th oscillating point by action of th WlCt'VIMO) 1C 1& jswT Conatructien of loop aerial. baae. Thla ahould be ao ronalructed that tha loop may ba turned eaelly. To receive a dealred atatlon tha loop ahould ba pointed towarda that direction. Htatlena at right analea to tha benp will not be heard unlaaa they ara very near and uaa a great deal vf power. NO OKOUNO. It ehould be noted that no ground la ueed. One wire of the loop la connected In placa of tha ground lead. Hince tha loop aertala are Inexpensive, It la auftgeetetl that tha radio amateur try aeveraj different dlmenelone and alaea. fciperlment alao with the grade of wire. The mora lurnl, though, that you have, tha higher the wava length received Hlnoa nioat regenerative receivers are wound for not more than Too meters, don't load up your loop aerial with too many turna. 1 Fig. 1. Three-tuner elrcult. j grid snd plate varlometera. Fig. 1 ahowa a typical three-tuner receiving re-ceiving set: I Variable eondeneer: I Verloroupleri I Grid variometer; 4 tlrld leak and con. denser: e Detector tube; 4 Kllament rheoetat; T A battery; I'late variometer; vario-meter; B battery: 10 Phones ahunled with filed condenser. A 6- |