Show fEli tood by 0 1 g kowt of V C 0 A high signal intensity Intend ty equal to four tube tubes ti Is obtained from this two tube reflex outfit the principle of the red x circuit depends on tir the of a thre alec vacuum tube to permit currents of different frequencies to voss through it at the lame same tiro time the frequencies quen qu encle cies of the curant induced in a radio antenna system are very rapid tarring varying in value from froin about tw to I 1 OW kilocycle kilo cycle I 1 air lr arconi I 1 depending en on wave length till this current in the tile antenna system Is I 1 generally termed the radio frequency current in a reflex system these radio frequency current currents are usually amplified to increase their intensity before impressing Impre asing them on the rectifier or da detector di ector which con vert verts these high frequency current currents into current currents of at audible frequency after rectification these curr currents ints are then amplified as a ft ere the radio current currents by a three electrode vacuum tube here lies the particular addan tage of the reflex system over other systems in other systems after fitter rectification the rectified fled radio or audio currents are amplified by additional tubes for thia this purpose in a reflex system before these input radio frequency currents are ire rectified they are relm pressed back on the tubes which an am them at radio frequency and when rectified are at audio frequency before being passed on to the receivers or loud speaker to be converted to sound waves there are a number of methods of utilizing the reflex principle among which are the type of reflex wherein the reflex action proceeds from the in put to the output tube in direct pro breslon gr gre eslon and where the reflex action Is performed in more than one tube then there Is to the lo so called inverse duplex system wherein the reflex action la Is not progressive but Is to inverted back toward the input tubes in the eria erla circuits the reflex action Is progressive from the input but Is only utilized in one tube due to the complexity of controlling radio frequency it Is not possible to successfully stabilize a system wherein the reflex action la Is include ed td in more than one staged it Is not a matter of balancing the loads in the various tubes as it can be readily shown that the loads caused by any audio signals on the tubes in these circuits are never such that the few care in connecting jacks for amplifiers where vacuum tubes and a it number of steps tep of amplification are used it Is sometimes advantageous to be able to connect in on the th detector tube or on one or more stages of amplification telephone jacks are a great convenience to those who know how bow to con hect them for this purpose if connected improperly they are an sources of constant coni tant trouble jacks are generally used to shift from one stage to the next there are other types which may be wired to control automatically the filament current this arrin arrangement gement Is a con one and results lp in a great saving of battery power wiring the jacks in an art amplifier circuit 1 Is a difficult problem and unless the builder has his some knowledge of them it Is best to leave them alone an amplifier am jack poorly wired will poll the efficiency of the set as a whole it Is best to avoid the use of flux jinx or soldering paste when soldering the connections to the tb terminals of the telephone jacks at times builders builder make mike an untidy job of this so to that when the flux Is heated it soaks through and finds its way to the pa ps ell above Is shown a it two circuit jack below the th single circuit jack per washers that he ile between the contact connections of the jacks this prevents josf energy from tk tak ing its proper course and the result Is 1 a weakened signal there are thrice types of jacks used in radio circuits namely open circuit jack the dose or two circuit jack and the automatic fliam filament ent lighting jack they are shown in the accompanying diagram there are also a it few jacks of peculiar make which tris n barial rarely used micro unite of at 11 nil 1 llalon ally ulon thein would our loud lond them nil as lui has been anany time stated in general there are two forms of axing 1 vacuum tul tulip tules es as radio frequency amplifiers L e the coupling transformers may be either t tunable una ble or fixed ahe tunstle type transformers are no so designed that they may be tuned usually by toy a variable Rr lalle cond cmor in the other type tile transformers cover a certain ranee without tuning the latter arc are broad brand and make for unselective reception it ie IS imperative flint if selectivity Is to be had where radio frequency amill flea fi catlon tion Is employed emp loed the coupling tram trans forneri for dutot permit tuning adjustment by a variable tuning device delce uch such ai as a variable condenser because the tran transformer Is actually tided to tie signal with this type of radio frequency amplification not only great ent selth selectivity ity if to obtained but greater amplification li to likewise secured either a it vacuum tube two or three electrode or any of the many form forms of crystal rectifiers of high frequency fr quency currents can be used as a rectifier we are told Ho however weier in a reflex circuit due to the particular location in the circuit and inherent characteristics of the detector a crystal rectifier will be more satisfactory ily by the ue use of the proper crystal rectifier an excellent controlling effect on the stability of the entire circuit may be had this feature Is not generally known but Is 1 demonstrated in the stability ot of the circuits using this form of a u detector Je net not every crystal rectifier which might possess high rectifying properties will he be found the best for thie this purpose due to the fact that the crystal can be made to provide a stabilizing effect on the reflex action of the circuit the fixed type of crystal natural ly requiring no adjustment if correct ly designed affords the best form of rectifier tor for the reflex circuit another point of interest Is the fact that not every audio transformer can be used in a reflex circuit la in a mile circuit the audio transformer Is associated coated with the radio frequency current currents of the circuits and requires a design and construction differing from the regular audio transformer hints for amateurs who build own sets in any circuit where one side ot of the condenser Is to connected to the ground it Is best to ground the rotating plates thus doing away with some of the hand capacity effects for real DX work a foot antenna with a it series variable condenser works very well although this Is not as selective sel ettive as a it shorter one surprising result results will be experienced for long distance reception as well ai as local audibility this Is an old amateur stunt in wiring a receiver lTer met all connecting wires should be short direct and well paced spaced from each other wire used for winding inductance coll coil should have as little insulation immediately surrounding the th wire as an possible this adds to the distributing capacity of the coll coil and results in loss of power and audibility it Is worth while to use dead end witches switches for dip disconnecting connecting the major part of the coll coil when not in use um why waste power by having the unused portion in the circuit for clearer reception use a 0 battery in each step of amplification this will double the life of the B battery as the plate will wilt only draw about half halt when a 0 battery ie la connected in the circuit very easy matter to destroy B battery A short circuit on a 1 11 battery will III destroy it in a very short time because the cells are small and the chemicals are rapidly gi exhausted baust under heavy beavy current currents often the li first warning of thi this condition I 1 Is when hen w the warmth of the battery Is noi noted ita the only preventive Is to connect connett a fuse in the circuit that will blow when too much current Is drawn this is I 1 a protection that few sets have habeil ha veil 1 la Is standard practice la 14 all other fields of electrical application chanting the direction of ot the this an lka tenna may increase the signal strength it if the antenna is built like a T the ends should point toward the station that the operator desire desires most to hear bear it it Is I 1 like an in inverted 14 L the elbow where the flat fat top and the lead la in wire win join should point toward the this afta ta station for the goudea |