Show USE OF CHOKE COIL AND transformers la latter e r provide the most practical t ic al method of coupling for the amateur figur shows the actual circuit of a three thrasi stage niam last resistance ma coupled amplifier the output of buch circuit la is 11 time K times K the input or im assuming muning the file ti factor of each tube to be 10 the output would be I 1 1000 times the input the waist resist race ance H R Is IR the eo coupling jiing resistance um whose whom function it lif Is to transform the p plate 1 ate cur current essit variation to potential d drops rep to be applied to the grid of the file next tube the capacity 0 Is simply a means of f allowing allow lag th the potential variations serum across the coupling resal R to lie be applied to the grid of f the next tube let not allowing the me B H battery up ap filed to the plate clicc circuit it of ft a tube to ve re ampil applied 0 to the grid gri d ot of the next strauss because of using the condenser to what one might a 1 insulate alte the grid from the on B battery pot list it I 1 la see sary to use nee k grid leak to keep ch the charge which collects 1 1 on em the grid ft aiom bew becoming tug excessive and red icing t the he P plate late current to zero eero one of the chief of the resistance net coupled amplifier Is that I 1 cry ry high plate battery pots poten da la are re necessary ry the am ampoules isdo t alon on per par tube b of a resistance coupled amplifier pit ft er 1 la rod not us high na it 1 la for fi wine other methods method but it 1 ta table stable and does toe not hot ill distort ton the input as much KB as do some alone other methods used which give greater granter amplification per tube R r coupled 9 in mav 1 v be used to amplify either radio 4 or audio a frequency cy A method of at 1 audia im the change 1 in plate eur current r at of at a vacuum tube lube to differences in potential to Is by 1 meana I of a ch choke ke coll coil A choke 1 coll 11 reinstate consists of a number of turns of wire wound ad up I 1 in if a multi if layer r coll it and may or may not at b have e an it iron eve core A e coll call of this kind offers a high 1 am veda fedance a to the flow of all alternating re tin g cur can rent rant but be baa a relatively low at direct current at resistance the tf choke choice coll 11 a on account at of b chiv hiv ing a low few illin resistance will be have live method of coupling BO that lower VI B battery potential ran can tie be feed on drake coll coil coupled amplifiers lid ad the me batteries batt erlea me can be of smaller specify th the e choke coll it set not only he has protect induct un ce but a certain amount of dila doted led capacity the en parity of the coil plus plu the capacity of the plate with map t to the filament element together with the inductance of the file tell coll give to the afia plate circuit a tain period that ae the plate circuit 1 la an merfi bit el circuit r t whose at frequency la gd determined C d br the total capacity slid and inductance 1 in the three circuit t the its choke coll call be made variable it if sot at only lady biform to transform the plot plate current calvent variation with pint plate potential variations variation but it will 1 iw erve to to tune out colt unwanted tro fro quencie a W when hen the p plate 1 to circuit of the amplifier 1 to toned the a frequency 1 la amplified K almea but off all the frea 6 are amplified pit to a heas derree degree another other and it by far the most widely file wed method of coup coupling lins on BUC castim tube 1 in a cascade do amplifier 1 I by mon of transformers transform era ahe trans former method of coupling amplifier opHner ar tube may be considered a develop sout and a refinement of t the be simpler choke coll call method coup coupling g tubes by comes of properly trans farmers will give a greater r cation per tube tub than ny of the other methods figure show how the of I 1 the am grated transform rr I 1 coupled r where P and 4 a 8 a are map rely the pr ra lmarie and tal serea derles A t the coupling tran transformers formers the ke BB a what a 9 sm design to conert an the PI plate current varla art if blob let into move potential can carfa thes w the plate circuit of each carl tuba h which includes the primary wi winding bilm of coupling ing buat be famil gried for fee amit maximum hems power empl if fl catlon I 1 while t 1 the name time ur ratio of 0 the transformer transform at immich be such a aa the to grid deliver circuit adt e maximum of the ham next am potential tube aio aa ch to I 1 lie me greatest ft a d of the s transformer method of coupling until f frequency ry a are the high deera me a of amp littin alion the relative alm fit f operation and ad ill the tow law plate it xe required chief komg file alie bild wage of t alie b transformer abc coupled Irel frequency liveley afi fl IB colim M AIO the he factor anners Carl amplify dif different frea mr to different which mcana a that whan be th alila it tp tire ol of coupling I 1 ta used ter lor fed lph lar reception eption ill alie voice la Is dimor ra bt be the amplifying morre IIo weier ft from a standpoint the average amateur will have better result using trans from former plad coupled audio adi frequency krapil pers pen than from rice other oilier method that can be used a ath ith the tubes and equip nip at now ame aall ble A 9 t 77 arl 77 |