Show 4 A I 1 T ja J ier n coupled 1 gaudio I 1 e dio aaion 1 wllis aa ff 0 audio amplify amp I 1 liff i cpr bome some alre bowed to resistance and Impi impedance dance coupling again up an fn takes t up its position among the le adera st J as lea enough it impedance Impe Imp idin dence to couplings li clings y wore era f far superior r lo in quality quallia of output toy tho the y 1 aa ld 1 transformer method 1 for litif W only ie very ry mediocre transformers hii with mith the advent to WOM many high quality transform ewa ert such ii aa of ra cent oi general Anier tran Sam sori suver li allader all american etc a to return turn to popularity of thi counted amplifier waa pro diet avan d t his quickly to be 11 1 tho ithe case cae A short article prepared by the i technical staff of radio broad Y I 1 has baa the following to x ay about the transformer coupled am ill flir ir inthe the A ic conventional transformer coupled 1 am consists of two staisia staak st aisea the overall amplification entson of ili buch ch i a alem ylem la ili generally tene rally ground around wo iid and athla to ill bagh to give loud speaker reproduction with a A signal available at the output of the tb detector the trans former coupled system ha has tb the ad vantage that only duly stages ars are to re oha add and c can an ih therefore ere it ors be made quin bolte compact the plate current con of finch au an amplifier lis la fair ly ir I 1 low ow a and ll 11 d only I 1 modem moderately tely high volt h agea baie are necessary on tb the first ata I 1 the 2116 quality of the results obtained do de primarily upon the transform envied and for this reason a c certain 4 r jj t amount of care car to la necessary in choosing thi the transformers that an to tb be incorporated in sick an am am amplifier pUder 1 M The I 1 asfor transformer mor feeding ceding out of the tnt I 1 r stage should hare a primary milry impero impedance 40 th t J c somewhat than ii necessary for that transformer used loathe second etim the hisheh impedance ho 6 la id necessary in the trena fan former feeding out of the detector tube due to the fact thit that the detector plate dreal circuit L generally has han a somewhat higher impedance than the plate circuit of a tube vied used ai pa ua a amplifier if two transformers of different ration ratio are to wil be used adt the h 6 rule la Is almost invariably to place the low ratio trans tram former in fit tufi the amati vol tor commercial Iner CiAl reasons put wk a fixed number num uk uw berof of ak tura aoa the wk uk uw ak 1 cecon darlea of their transformers lr respective 0 the catl Wrid reL ita tb 4 different ratio r a tf values value are then I 1 ol tallied by wt c on tb number of primary ahli latter figure of course coone I 1 marylne proportion ally with the ratio tha thili th the 9 lower the ratio the the number of primary turns and like ni lik 6 clr j greater the primary impedance tripe dance proper C battery on the tabea Is absolutely I 1 good gb Q quality it Is to be obtained the 0 O battery volt age oo on the flatt haeher than la Is ne cesary to it overloading alef placing c to 9 an ft I 1 high blaa bias on the fart tub ili yiewei the plate impedance jot the tuba and it Is essential th that if the hi plat be kept low I 1 I 1 4 if a tuba li la died y 14 in thel the axi state stage with ft a 40 volt C blizil we can impress signals on tha thirld ad d I 1 ofala of tube which havea have a eg us to 40 volta if the thetla naf bail hadj a ratio batig of 4 L tb the wjk 1 I voltage in 7 0 im 10 I 1 voltee if a tubers tube js tn uter R t a ge we can am abt a I 1 6 tb voltage on lt r voltage in inthe the plate oate alie e which give sItA vita lt fa tollow ja then that a C battery alif all of 1 I awit in the first tube lube will 14 it eat to tj r r vent overl overloading I 1 91 1 41 |