Emerson-Radio-and-Phonograph-Corp-888 电路原理图.pdf

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1、VOLUME R-18, MOST-OFTEN-NEEDED 1958 RADIO SERVICING INFORMATION Emerson CONTACT PLATE / CONTACT J SPRINGS TO CHASSIS BATTERY REPLACEMENT LABEL CONTACT BOARD Chassis 120374, Model 888 ALIGNMENT INSTRUCTIONS /s/sss/1 0-1 R22 I.NEG _ * T 1 f L2 5* s s *_/ - 4 455KC 600KC f* i GENERAL DESCRIPTION Model

2、888 TRANSTIMER II Is a completely self-powered 8-transistor superheterodyne portable clock-radio. The clock-timer, in conjunction with the associated circuitry will provide “automatic turn-on of the radio or a buzz- alarm*. Either can be selected with the front panel control (switch on volume contro

3、l). The buzz-alarm sound emitted by the speaker is created through regenerative feedback in troduced by R-25 and R-26 in the last two oudio stages (Re. figs. 2 ND 19074 01 *“T11 0,SEVCD OnMOOlO 1 1 t U J I T i if ONE OF THESE TRANSISTORS 10 7 OR Q-B) I BECOMES DEFECTIVE .REPLACE BOTH OF THEM FIG. 1

4、- SCHEMATIC DIAGRAM, CHASSIS 120374 (VOLTAGE READING CONDITIONS ON PfcGE 3fc) i *S* J 600KC - R-23 5601 * 4 BATTERY - CONTACT BOARD ll 4SSKC 21 c-5 I* *Jl6MFD VAR CAP ML. p. 22 *r a* .az*m tkS c-4 SP 004 T.Jj.r I1 K If 43ri -A8 C-7 HMED . 45SKC JI 5-4ic * c-ioX SMFDr R-14 sZM*, ZK-f jrjSK tfCVl t /

5、NOTE # REFER SCHEMATIC, FIG.I.PG2, FOR VALUES EXTERNAL LISTENING ATTACHMENT JACK ITERMINAL VIEW) TRANSISTOR PAIRS ASSOCIATED Q2 Q3 R12 815026C 815026 A 680 815026B 815026B 680 815026 B 815026D 680 815026C 815026E 680 815026D 815026 D 680 815026C 815026 F 330 815045C 815045E 680 815045D 815045B 680 8

6、15045D 815045D 680 TRANSISTOR SUBST. TRANSISTOR FOR USE NOS. 815026B 815026D Q2/Q3 815026A 815026E Q2/Q3 815026C No subst. Q2/Q3 815026F No Subst. Q2/Q3 81502 815032 Q5 815031 815032 Q5 815033 815032 Q5 815034 815032 Q5 815035 815032 Q5 FIG. 2 - ETCHED PRINTED CIRCUIT, CHASSIS 120374 (TOP VIEW) TRAN

7、SISTOR Q5 ASSOCIATED R14 815031 3.300 815028 8,200 815032 4,700 815033 6,800 815034 8,200 815035 10,000 ANTENNA mtt 0-1 PNP ERTERxl* t-a r lUMFW_ .V CT-A rn TRIMMER R F MOO KC 0. Vl CT-B TRIMMER OSC 1640 KC |l i ( JaSJ Q-5 -MATCHED PAWl ff NPN /y* j lit AUDIO T - V, W R.lSs. AMP T 4l N y/ a sij ; pn

8、p w VOL. 7 w*M AUDIO xont y wp 0-2 PNP OSCILLATOR CT-A TRIMMER i RF 1400 KC CT-B TRIMMER OSC 1640 KC OKC j|_I 0-4 _ O-B audio ci:; OUTPUT-*.TO 0-Tl o T_4 HI : o-6 ! Hp l, DRIVER FIG. 4 - TRANSISTOR -7:- HOLDER * “RED-(T)- H0LDER ETCHED PRINTED CIRCUIT, CHASSIS 120655 (BOTTOM VIEW) TO SPEAKER SP-1 HBXL) 33