Scott-342-Service-Manual 电路图维修手册.pdf

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1、SPECIFICATIONS TUNER (PM-MPX) H. H. SCOTT, INC. 11 . POWDER MOLL RO., M.VNARD. MS., 0075 SERVICE MANUAL FOR MODEL 342 SOLID STATE STEREO TUNER/AMPLIFIER 2.2 microvolts 80 db Usable Sensitlvity (IHF) Cross Modulation Rejection Signal to Noise Ratio Total Harmonic Distortion Frequency Deviation (Drift

2、) below 100% modulation *Frequency Response Capture Ratio Selectivlty Tuning Range Accuracy of Calibration Separation FM should measure +12 ;tlv. 1. Mono Alignment and Sensitivity Check Front End and IF Alignment With about 10 uv generator output, align and peak front end for max. output. With 3 uv

3、input, align IFs for max. audio,. With 1 or 2k uv input; align detector for minimum distortion. 2 . Sensitivity and Distortion Measure sensitivity of tuner with Zluv RF input, at antenna terminals. Must obtain 30db usable sensitivity at 92, 98, and 106 me. Recheck distortion, 2k uv input. 400 cps -m

4、ax. distortion of O.St. 3. FM Huro Check Tune to unmodulated signal, measure min, of 60 db (may reverse AC plug) De-emphasis Check Change Hod. to 8 kc, from lOOt modulation note decrease of 12 t 2 db in output frOlll 400 Hz reference Calibration Check Check calibration against stations -max. toleran

5、ce+ .2 me. 4 . Multiplex Alignment -Unit to Stereo a.) Pilot Adj. Scope probe (Low-Cap) to test point L501 peak T501, and L50l for m; , lrco ,J., ,._ , . ,., - Cll/J ClO? .001 -1.-cz-,-?-1- I lil!Vtx: R/zo; I I I I I I c.209 c2rn 1$ NP() l_ _ l t I I I I I LZO? O 11 = .,-w - (J4. tMQ.,tr ,000. ,zas

6、-EST SC-IIS Rz, czu Ut7 I H.H.SCOTT, INC . . M . ( CIRCUIT 1IAGRAIW KAll: I tct I -n, or , I C Z,.M/.5 t:.I All voltages measured with 20,000 ohm/volt VOM; 300 ohm antenna and no signal. 9201 G .025 D 9.2 S 1.05 Troubleshooting Guide Trouble Low gain No Output 101) 161!:I 0202 B .45 E .OS C 10.8 Pos

7、sible Remedy Replace Q201 Q204 B 3 E 2.6 C 10.2 Open LRFC 2.2 or .33 defective Q201, Q202, Q204 3 RadioFans.CN 收音机爱好者资料库 6 0 : . .c TOrao,TolOo - . 7 -,. . -7 - -I - ,.-1 ,- 4 -I - I r r - . I ,-;I., L 2 no, - fT o.:ot -12 1 ;., ;o,s . ,. .,. _ _ -n: -,-, : l fl 1 lM ruo . I I - illla.-4-lY-,: -t.a

8、gg: r t y? :no U I, .-11 -,.;n. iao-4.:.+-:-.n L _ _ji-U-,-u7 RoJtp-3: ,or. I I ti,.- 7 m. I I I l . ,.,. . I r:l:. . r-,-J-r-i,_-r_7 1,. 1 l e - :! ,l I + -J: I 1 l Tc;: 4 _, . . i . _ , - -L:.:_- -t-9-r-:r-1., I = ,. - ?, - ! L I -r-L-I -_ -AO, ,-o.c A.GC (tt11-co,t;) Td.n l4Vll WGt.O I GiNO ulYC:

9、 . , voe v.ft J.e., . . . _ . I 1 t T: 1 . I0,7 . h ; ,. FM If -IFIEI , . ) NO,OM.) H)C.M$ r ,U - o,o cu DJ Jo, 4 QIO 30,V SQ 11 (Rtt .,_ ifT.:0 -l!N ncul .,_ 4.US OWtt.li -1,11.M;:;,; 1:UfST.Ct ,. c,.w5 ! 10,:. Alll.llOtU . fllGllf t C,.rur( M MP :,0.L t C)_(: v.)s.:ifl ! lCA _,.) z-PC-11 .01 II :

10、: . r t t l!l:-. . L.- ii l I u LU t- ,J. ( _,J LU 0. :c u 0 . . -t 1 . .,. - y. IO :!;o s . - - i:o:; I - 1 ! ! i I:- 1ze!;i 1 I I., ;: : I h I ;, ir. I : i I H I . I . -;, I a I . , !.I _ _J : 1 X t ! ? - ,. -! TGD 1513 PRE AMP Ql ,QlOl I-2N2925 2N3711 Q2,Q102 or 0 ,Q.-. ,., . . ,.10:;:; -J . . ,

11、. G C 1 ;-9 :; :.-; _.,.,.,;.-10-:1-t, JCb(?/), . -ajr ;:t cmz, = : : -.i: + :. _ -, . c 2 9.: ? = .-:r _.-y-._ .qr 1I/ :=:= ;f!:;it ., . . + . ():.:,: . , . ,cfoZ.-:. : 0 :i :/:. : : . . ! ii;, Signal Path through PCPS board and OJ and II Input Signal W and (II . 02 Volts rn and 1 Volt II and I! 1

12、Volt Output Signal CAPACITOllS Cl, ClOl-CC-68O 101 c2, c102-cc-47O 101 C3, ClOJ-CC-33O 101 C4, Cl04-CBPC25/2S cs, c1Os-cc-100 1oi C6, ClO6-CEPC2SO/3 C7, Cl07-CEPC5O/15 C8, Cl08-CEPC2/2S C9-CEPC5O/3O TRANSISTORS Ql, Q2, Ql01, Q1O2-2N292S TGD HH3 9 4 RESISlOI. Rl, RlO1-RC11-6.8R R2, Rl02-RC11-l.5K R3,

13、 RlO3-RC11-22OK R4, Rl04-RCll-l.2K RS, Rl0S-RC11-5.6k R6, R1O6-RC11120K R7, R1O7-RCll-820 R8, RlO8-RC11-68K R9, RlO9-RC11-470 RlO, RllO-RCll-l.8K Rll-llCll220 CHOKE Ll, LlOl-LRFC.OS 0 TONE CONTROL, DRIVER Ql, Q101 -QA 11 Q2,Q102-QAIO Q3,Q103-Q27 Q4,Q5,Q104,Q105-Q2N2 OR Q2N3710 9 4 OJ ond II).7 Volts

14、 i and zJ 2.5 Volts I and w 2.8 Volts and 30 Volts 0 II and Q) 32 Volts Signal Path thru TD-3 board and Peak to Peak voltage meosurements acquired with 8 ohm lood and .5 Volts input. - TROUBLE Intermittent output 1 channel (All positions except xtra) Blown outputs No Bias Adjust Intermittent High Ou

15、tput TCD 1513 POSSIBLE REMEDY Intermittent capacitor or cold solder connection on Pc PS board. If trouble is corrected by switching from stereo to mono it is definitely in pre-amp. section. If not trouble is in TD-3 board. Bias should adjust smoothly, if not 1 of DSI-ls is open (3 in series). Shorte

16、d QP-8, QA-11 or QA-10 no good. (All trans- istors in strng should be changed if outputs are blown) (QAlO & QA-11) shorted DSI-1 open 50/15 (feedback cap)(C7, Cl07 on PC-PS) 10 342 MASTER PARTS LIST Z-PC-TD-3 CAPACITORS Cl, ClOl-CEPC-50/30 C2, C4, C7, C102, C104, C107 -CEPC-25/25 03, Cl03 -CEPC-250/

17、3 CS, Cl05 -CEPC-100/6 C6, Cl06 -CEPC-10/15 ca, Cl08 -CMM-.068/250 C9, Cl09 -OIM-.068/250 ClO, CllO -cc-.0047 Cll, Cl2, Clll, Cll2-CEPC-2/25 Cl3, Cll3 -CC-330K Cl4, Cll4 -CMM-.047/250 Cl5, CllS -CC-22K NPO Cl6, Cll6 -CCM-.22/250 C201 -CEPC-150/30 TRANSISTORS Ql.QlOl -QA-11 or TA2670 Q2, Ql02 -QA-10

18、or QA-lOA Q3, Ql03 -2N3567 or QA-10 Q4, QS, Ql04, Ql05-2N2924 or 2N3710 RESISTORS Rl, R3, RlOl, Rl03 -RC21-390 R2, Rl02 -RC21-1K R4, $104 -RC21-3.3K RS, RlOS -RCll-82 R6, Rl06 -RC11-12K R7, Rl7, Rl07, Rl17-RCll-lSK R8, Rl08 -RCll-220 R9, Rl09 -RC11-12K RlO, RllO -RCll-270 Rll, Rlll -RC11-3.3K Rl2, R

19、ll2 -RC11-68K Rl3, Rll3 -RC11-l.2K Rl4, RlS, Rll4, Rll5-RCll-2.7K Rl6, Rll6 -RC11-56K Rl8, Rl9, Rll8, Rll9-RC11-10K R20, Rl20 -RC11-12K R21, Rl21 -RC11-3.9K R22, Rl22 -RC11-6.8K R23, Rl23 -RC11150K R24, Rl24 -RCll-1.SK R25, R125 - -RC11-330K R26, Rl26 -RC11-l.8M R27, Rl27 -RC11-6.8K R28, Rl28 -RC21-

20、470 R30, Rl30 -RC21-180 R31 #-RCll-lK R201 -RCll-330 R202 -RWS-750 R29, Rl29 -RW5-12 R32, R33, Rl32, Rl33-RCV-10K/1K-PC R35, Rl35 -RCVCC-lOOKT-PC TOD 1513 11 Electrolytic Printed Circuit lype II II II II , II 11 II Capacitor Mylar Molded II II II Ceramic Capacitor II II II , ti II II II Electrolytic

21、 Printed Circuit Type Ceramic Capacitor Capacitor Mylar Molded Cera1nic Capacitor Capacitor Mylar Molded Electrolytic Printed Circuit Type Transistor II II 1/2 Watt Carbon Resistor 1/2 11 , 1/2 II II II 1/ 4 II ti II 1/4 II II II 1/4 11 II fl 1/4 II II II 1/4 II 11 1/4 II II ti 1/4 ,1 ti , 1/4 II II

22、 II 1/4 II II ft 1/4 Ii II ti 1/4 II Pt II 1/4 II II II 1/4 11 11 II 1/4 II ti 11 1/4 II II II 1/ 4 II II II 1/4 II ti II 1/4 II II II 1/4 II II II 1/4 II tr II 1/2 11 II II 1/2 II II II 1/4 If II II 1/4 ti II II Wire Wound Resistor II II I I Variable Carbon Resistor Carbon Resistor Concentric Clutc

23、he Part# A-DC-15 AFW.B CBDl-5/15 CEIM-2 so/ 30 CEIM.-1000/30 CElM-1000/50 D-CM-3 DZ-12 F-AGX-2 F-S8-11/4 .J-3ST-5 KNP6LTI (1) KN-P-6CTI (3) KNP8CTr (3) KN-P-lOPTr (1) M-SS-10 N-342-1 N-D-FM- 17 RCV5K-PH QP-8 RW-2-.82 RW-5-390 SPS-12-3 SR-1.5-50 SRW-115-2 SS-22-3/3A SS-43-3 TR-.8-9 VPL . 49 V-PL-1847

24、 Z-FM-15 ZPC-lF-1 Z-PC-MX-ll Z-PCP8 ZPCTD-3 342 PARTS PRICE LIST ( Subject to Change Without Notice) Description lial Cord Flywheel Assembly Electrolytic Capacitor Electrolytic Capacitor Electrolytic Capacitor Electrolytic Capacitor Diode Zener Diode Fuse (Speaiker) Fuse (Fower) Phone Jack Plastic K

25、nob Plastic Knobs Plastic Knobs Plastic Knob Meter Panel Glass Dial Potetltiometer Power Transistors Wire Wound Resistors Wire Wound Resistors On/Off Switch (Power) Rectifier Rotary Switch Slide Switch Slide Swit,ch Power Transformer Neon Light: Bulb Pilot Light Bulb Front: End IF Board Multiplex Board Preamp Board Driver Board TCD 1&13 12 Customer List $ 1.75 4.80 .84 1.68 2.45 3.48 .32 2.24 .24 .45 ,65 .65 .65 .65 .75 5.94 8.55 2.94 .84 6.00 .35 .32 .40 3.15 5.76 .30 .40 18.00 .30 .40 48.24 40.00 36.60 13.85 26.96