Show rl k 41 1 1 m edited by G douglas hardro p editor 0 f ita d to M merchandising by 0 L INQRAHAM one of the unfortunate character of a radio fan la Is his never end g scan li for the set in conducting this lie tries many hookups hod kupa kups ohi frenk freak and standard and inai invariably ir 1 ends up tip by using one of the old such at as the giree honey bone y knib or the two set still aa ITA vl av BA B A circuit diagram to be used to wire up amplifier unit even then they are constantly being improved by the fan and it seems seema to be the chief desire of most fans to add a stage of radio frequency to their sets seta as soon as a good hookup for same can be found the parts necessary besides a unree honeycomb coll coil tuner are one amp amplifier lIfler tube socket and rheostat to fit it tube used onto one maj mad variable condenser one 75 turn honeycomb coll coil and one turn honeycomb oil one neutralizing condenser a panel 7 by 10 inches and a baseboard for the amplifier tills this circuit diagram Is given in pig fig 1 this thin Is the for the amplifier anile the circuit riven given in fig 2 Is the diagram for the complete circuit amp amplifier lifler and three honeycomb coll coil tuner the circuit given in fig 1 Is the circuit diagram that should he be used to wires wire up the amplifier unit on the the 7 by 10 inch esnel before preparing the panel the t two we honeycomb colla coils should be tapped in two places the first tap is approximately on the twenty fifth turn and the second tap at approximately the fifteenth turn to do this take a turn hat seems decma to beabout hei one third up feann th inside J OT the coll coil and pull it ou out t with a knife blade then scrape the insulation from this turn at air the point it protrudes from the coll coil the 50 turn tap Is prepared ta lu the same manner the turn coll coil Is tapped in the renter center to find the exact center of this coll coil will be rather hard and it Is therefore suggested that two taps are brought out one each side of the coll coil at approximately the fiftieth turn ane correct one can then be found by test when the set to Is operating turn coll coil Is the aerial tuning inductance for the radio fm frequency quency amplifier the two taps and the end iwo complete circuit amplifier and honeycomb coll coil tuner of the coll are connected to the he switch points on the panel and the inside end of the lie coll coil Is connected directly to the aerial the rhe switch seitei lver lever Is connected to the ground as shown in the diagram on the liand annd edge of it the am panel binding posts ore ire pl placed aceti one of these la Is connected to the plate one to the ho 11 II buttery battery and one tu to the neutralizing condenser the b battery a t t e ry binding posts should be brought out on the lie baseboard the nerla und and ground binding posts being at the left nand end of the panel switch may be added in the three col coil receiver a switch may he placed in the set to disconnect die primary condenser wien alien the radio frequency amplifier Is in use or the condenser may be by a piece of wire lre when using the amplifier whichever Is done remember that it Is necessary to cut the primary condenser out of the circuit when using the amplifier when the radio frequency amplifier has been wired up according to the diagram in fig 1 to test it it should be connected to the three honeycomb coll coil set by connecting the binding posts on 01 the amplifier that are connected to the plate and the neutralizing trall zing condenser to the aerial and ground posts of the three honeycomb coll coil set the 1131 B battery posts of we tae amplifier should be connected to a piece of flexible wire ire then the LOD turo turn coll coil that was tapped in the center I 1 la s put in place of the coll coil generally used as the primary coll coil in the honeycomb coll coil tuner the secondary and tickler colla coils are left on the hie tuner the same values being used with the amplifier as aa without the flexible lead front from the CB battery post on the amplifier Is t then hen connected to the center tap on the turn coll coil light the radio frequency quen cy amplifier tube and the detector tube cause the detector tube to oscillate and set the secondary condenser at about the setting generally used for whatever station la is on the air at the time of testing then tune time the aerial circuit with the taps and the 2 23 1 plate condenser adjust neutralizing condenser when a whistle Is picked up tune in the station and then adjust the neutralizing condenser until the radio frequency amplifier does doea ant oscillate ane best method of doing that Is to move the neutralizing conden condensers brass or nickel plated tubo tube back and forth until a point Is found wherein lie tuning of 0 a station Is smooth and not by clicks that Is 19 when the aerial tuning condenser can be tuned past a station setting when the station Is tuned in on the detector tube without clicks being heard in the phones then the lie tube Is neutralized lf if it la Is found that the tubes do not seem to neutralize perfectly shift the flexible lead to another top tap and try again it if the four ups taps do not allow neutralization it will be necessary to make new ones though this will not he be necessary in most cases new york sun |