Howard-Radio-Co-425-A 电路原理图.pdf

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1、MANUAL OF 1939 MOST POPULAR SERVICE DIAGRAMS Howard Radio Co. Models: 400, 40Q-A, 425, 425-A. Model 400 Is a 12 tube, 3 band receiver with all coils shielded. See Fig. 4, for coil location and information on trimmers and pad ding condensers for each band. The 6F5 is a bass boost stage. The 6J5G is a

2、 phase imverter with push-pull OVOGs in the output. The schematic of the model 425 illustrated is the same for the RF and IF stages. A single type 80 rectifier is used. Model 425 is a 14 tube set having GLCGs in the output. Models 400-A and 425-A have the same electrical circuits as the 400 and 425.

3、 These models employ the Howard motor automatic tun ing feature by use of the reversible motor controlled by the com mutator disc near the back of the set. ADJUSTMENT OF HOWARD MOTOR AUTOMATIC FIRST - Select and depress the push-button by number that will Include the desired station according to fre

4、quency chart listing below:- 收音机爱 好者资料库 RadioFans.CN MANUAL OF 1939 MOST POPULAR SERVICE DIAGRAMS LOCATE THE SAME NUMBERED STATIONS CONTACTOR ON BACK OF TUNING CONDINSEIl THAT CORRESPONDS TO THE BUTTON DEPRESSED IN FIRST PARAGRAPH,AND SLIDE UNTIL THE DESIRED STATION IS TUNED IN. With the muting swit

5、ch In ths OFF position the stations will be heard while moving the slide contactor. For silent tuning after all adjustments are made, turn switch to ON pos ition. THIRD - Remove station call letter tab from tab sheet and Insert In place with finger tip In front of escutcheon plate over the number that was selected. Repeat above procedure for each of remaining buttons. NOTE - When tuning the set by hand or If a remote cable Is used the selector button AUTO- OFF must be depressed. 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN