Scott-342C-Service-Manual-1969 电路图 维修手册.pdf

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1、-411 -Wv-Wv-1- 5 ERV ICE MANUAL FOR 342C SOLID STATE .3. ;y _., ,-RECEIVER . Scott where innovation is a tradition I SCOTT0 H. H. Scott, Inc. 111 Powdermill Road, Maynard, Mass., 01754 , . ltn I I-,_ IV 1 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 -. - - - C BOARD LAYOUT 2nd 19 KC Adj. Power Am

2、plifiers 67 KC Adj. 1st 19 KC Adj. Multiplex -Bias Adj. -Offset Voltage tlj. PreampJ ifier Muting Adj. Separation Adj. 020 1114 004 2 024 1114 001 IF section RadioFans.CN 收音机爱 好者资料库 Equipment Needed Audio Oscillator VTVM Oscilloscope Triplett VOM or equivalent 8 ohm load Attenuator Distortion Meter

3、117 V. Source AUDIO SECTION Set Controls to the Following: Sp-2 Input Selector Stereo Switch Tone Controls Loudness-A.C. Vol. Comp. Sp-1 Balance Pot. OFF Extra-2 Stereo Flat O Full CCW Loud ON Flat O Preliminary Visual Inspection and Continuity Checks . , , AUDIO :,tCTIO Inspect unit for defects suc

4、h as broken wafers, loose stand-up resistors, cracked terminals and jacks, and other such defects. See transistor precaution list. Turn bias max. ccw. 1. Offset. Bias and Voltage Checks Turn unit on. Watch carefully for any signs of voltage shorts. Checkmain supplies for +27 volts and -27 volts. At

5、the emitter of the QP-11 on the power supply bracket, check for 12VDC. Bias measurements have to be taken with triplet meter directly across either 82 ohm resistor on driver board. With both leads on either resistor adjust Bias pot (pot nearest rear panel) for .6MA (12 MA scale). Offset voltage will

6、 be measured between either channels output terminal and ground, for O volts t 100 millivolts. 2. Sensitivity Check Input selector to extra-1 at .40 (+2 db) input. Connect 8 ohm load to Sp-1 jacks. Turn loudness pot to max., observe output of 24.5 watts (14 V). Check tapeoutput jack with troubleshoo

7、ting lead for same input signal as above. 3. Distortion Check At 14 V output max. distortion 0.6%. 3a. Balance Pot With j.nput and output connected to left channel, note loss of O db when pot is rotated to L position. When pot is rotated to R, note a 4S db drop in output. With input and output in th

8、e right channel, pot rotation to R will indicate no drop in output, and in L position a 4S db drop will occur. 3 D10 SECTION 4. Tape Monitor Switch Check Audio Osc. to EXTRA at .4 V input to L channel. Note output at left channel speaker terminal. Put tape monitor switch in the IN position. Note los

9、s of output. Connect jumper cable from L channel to tape OUT to L channel tape IN, Note restoration of signal out. Repeat process for R channel, then return tape monitor switch to OUT position. 5. Speaker Switch ;. ,. f - ,i, T. 0 N L O N T R 0 01, Q 101, 020-1112-oos TONE CONTROL ; B RI I Rl04 I 2.

10、21( I IMEG z I QIOI 1 3 A I SASS I Cl04 011-1125080 CIO!I L _!50:_! J ,0068 ,0068 1 C602 500/20 PC. BOARD 019 II 07 064 NOTES: I.UNLESS OTHERWISE SPECIFIED: RESISTANCE IN OHMSr!OII. 1/4WATT, ANO CAPACITANCE IN MFDS. 2. QI, QIOI ARE H.H.SCOTT I 020-1112-oo!I. 3.HIGHEST SERIES NOs ARE: Rl0,RIIO,R803,C

11、9,Cl09,C802,Ql,QIOI 4. WHEN TONE CONTROLS ARE IN FLAT POSITION,THE OVERALL VOLTAGE GAIN OF THIS CIRCUIT IS APPROXIMATELY UNITY. (Odbl !I. THE FOLLOWING CONTROLS IN THE LEFT CHANNEL ARE MECHANICALLY CLUTCHED WITH IDENTICAL CONTROLS IN THE RIGHT CHANNEL, LOUONESS,BALANCE, TREBLE,BASS. 7 R603 I IK . LE

12、FT AUDIO OUT GROUND B+OUT +15.0V B+ IN +ze.ov RIGHT AUDIO OUT GROUND B-OUT -,a.ov B-IN -21.ov DRIVER INPu; GROUND C301 d-J25 + n Q301 ; 51990 Q302 r QA-10 Q3O3; QA-10 Q3O4; QA-17 0305; 2801 -020-1111-010 0306; 2901 -020-1111-011 POWER AMP. DRIVER C304 lONMENT , TUNER SECTION et Controls to the Follo

13、wing: Input Select. Switch FM Inspect unit for defects such as broken wafers, cracked terminals and jacks, binding tuning condenser, broken components, lead dress. Make certain all transistors are firmly seated in correct sockets. Take output from Tape Out Jacks. 1. Mono Alignment and Sensitivity Ch

14、eck Front End and IF Alignment With about 10 uV generator output, align and peak front end for max. output. With 1 or 2 K uV input, align detector. Bottom slug for Max. audio output and top slug for min. distortion and perfectune light to light. 2. Sensitivity and Distortion Measure sensitivity of t

15、uner,with 6 uV rf input. Must obtain 30 db usable sensitivity at 92, and 106 MHz. Reche_ck distortion, 2 K uV input. 400 Hz - max. distortion of 0.8%. Audio output spec. at 1 K 1.5 to 2.5 and AGC meter spec at 1 Kat least 3 divisions. 3. FM Hum Check Modulation Off, measure min. of 55 db (may revers

16、e ac plug). De-emphis Check Change mod. to 82 RHz, note decrease of 12 t 2 db in output. Calibration Check Check all calibration against stations - max. tolerance t 2 MHz. 9 - - ULT I PL EX ALIGNMENT MULTIPLEX ALIGNMENT 1. With the two pots at max in direction shown by Fig. l, prepare to align the 6

17、7 Kc trap and the HF SEP trap. Tune to a signal modulated with 67#Kc and with a low capacity troubleshooting probe on pin 3, adjust the 67 Kc trap for minimum output: Leave probe on pin 3, insert composite stereo signal and adjust HF SEP trap for a straight base line as shown in Fig. 4. J.-OklO At:J

18、usrr:o (IF THE NEXT SET OF ADJUSTMENTS ARE NOT DONE CAREFULLY, PROPER SEPARATION WILL BE DIFFICULT TO ACHIEVE) 2. Move probe to pn 1, while still on a stereo signal adjust first 19 Kc can for maximum output. The second 19 Kc can should also be adjusted at this point for maximum output. 3. Move troub

19、leshooting probe to pin 13 and align the 38 Kc can for maximum output. (No alignment of the 19 Kc circuits should be done with troubleshooting probe at this point.) 4. Now that all the alignment has been completed, separation can be achieved in the usual manner by rotating the separation pot, adjust

20、 for MAXIMUM achievable separation (absolute minumum of 30 db). 5. Any phasing that is required must only be done by slight adjustment of the first 19 Kc can and only the first 19 Kc can. If the 19 Kc and 38 Kc adjustments were done carefully, separation should fall within+ 2 db between channels and

21、 going back and forth between stereo signals for readjustment should not be necessary. . 6 To set stero light and muting, set muting switch to ON position, adjust mute light and adjust pot until unit mutes. (tune to either end of band, adjust on noise). 10 J6KC - SEP. AOJ 0 FIG 1 0 IC MULTIPLEX NOTE

22、S: 0 0 I. CIRCLE MARK ON TOP OR INDENTATION ON LEG OFIC INDICATES PIN NO, I 2. GREEN DOT ON TOP OF TRANSFORMER OR COIL CAN INDICATES PIN NO.I ! . . I Iii 0 i f_,-(;).-.-,-.-.-0 4701. 470 s l:i. . . 10 I? - II .,. .0011 .,. . MULTiPLE . ,. IIPAIIATION Al,I, . Ill . OUT 110 ,0011 ,0011 . . L!fT . : PI

23、LTH . OOI IINIIIATII AMP 1C-301 p.A703 1C-302 .,.A703 020-1114-001 020-1114-o 01 1C-303 .u.A719 020-1114-004 1C-304 (SCS117) 020-1114-006 FL-301 024-1144-001 CRYSTAL FILTER IF AMP. NOTEI INDICATES PIN# 1 .-,-,-z._0_v _ L_s0-,-,- 2-.0-v- 9 :-? I lD n g 02CHll008 C51O a+ C-1/1/,. HIIN e-+-.,.ll LOW C-

24、.-.,._-i., I -: R50S 11307 10011 470 : Ol-+.ZDV:,_.:=;N01SE=-. _ _.I/IJr-+-l/l/r-+-lM-4 11311 811 C521 V PIILL 0.0V NOIH 14-001 14 . IZVDC INOICATOII UOHT I +v LOW !II o,:.,:.,.:.,;:,D,IIOl,1-D3.-R301,-.-1H -n +I.IOV I i ;:; _ ISO_IC _ D Lll=r I f;: rV/c,-+-111/r-Wl,-.J:ILf . :_i_. _ -+-ol A:c lua 2

25、20,1 0 V ,uLL INlUT .HVNOIII _ -_-_ . -:-o- GND CRYSTAL FILTER AMI, HOTEi: MULTIPATH INDICATOR L UNLESS OTHIIIWIII llECl,iED; IIIIIITANCI IN DNIIU 1O,r, t,ot WATT, AND CAlACITANCI IN MFDI 1.IIIHEST SEIIIEI IC 104,FLllOI, nor, LllO7,CSH 11120 ,DSOI I. DOT ON lOTENTIGIIITIII INDICATII EIITIIEIII CW PO

26、SITION YIIWID PIIOM IINOI IND, NOISE ON D NOISE OUT IN PC BOARD Oltll07011 12 -Co) _ lffSCOTT SPECIFICATIONS CENTER FREQUENCY: 3 dB BANDWIDTH: 20 dB BANDWIDTH: 40 dB BANDWIDTH : INSERTION LOSS: TERMINATIIIG IMPEDANCE: OPERATING TEMPERATURE RANGE: PASS BAND RIPPLE: PN 024 -1144-001 STAMPED OR SCREENE

27、D ON TOP 10.7 MHz 240 kHz (MIN;) 600 kHz (MAXJ 1200 kHz (MAXJ 6 dB (MAXJ IN/OUT 900 Ohms-/10 pF -10C TO 50C I dB (MAX.li1 20c TO soc) 2 SWEEP GEN. CIRCUIT .02 .oz FILTER UNDER TEST IN GND + 12 voe CRYSTAL FILTER TEST CIRCUIT r-, +IZ V. INPUT I I -:.J-_ .,. _ +-r-1-, I I N.c.(!) I I GND. 1,)-., _ -4

28、_ ,._-4,._ _ -l_+-.- I I I I I I I . I t I I I . I L _ J OUTPUT LJ TOP VIEW SC5117P COMPARATOR tc A703 3 4 5 DETECTOP a 11 JC:E. IN OHMS .:l:tOX, RE,10.Nl. PPLIED BOTTOMVIE.V, 1.201 f)RAlf.) 01 . l(lJ,3C:,2 I Ml,C. C.011. 14 BOTTOM v11:w 3TANOARO TR C,.lj iffl Dar TO If INPUT LOW HIGHE.ST SERIE$ NUN

29、l9ER., A.2. ,2. cz.2., 1.2.ow ; . R2f 47K,; .oo: =: .ooc5!: lO: 0 I m 0 . . :!: .J . I- :, 0 .J PREAMP. ,- 1001333013 11 7_ 14 8 e 1. J _c-es I IC 1 7 -= s 2- ,_ - L- C: BA ss I R4 RI04 z= TREB QI 6S B-OUT -CJ:s4 LOUT 10: B-IN c; LE RB RIOS 7 ROUT D:() ,a s 9 B+IN - 6 0101 B+OUT ID R601 II IALANC E

30、12 ._ IS 14 R2 RI02 15c:, .N.C OUDN 11c: i-Nj) , 11- T 18 TONE CONTROL 100-1334-003 10 DECK I REAR RI 5.6K v II 1!.L. l 2 !I - OA.:J :S 4 B 5 7 6 R4 470: -:.:- I -= 3 4 7 DECK I FRONT - INPUT SELECTOR SW. POSITION INICATED FULL CCW 023-1137-043 SW-1 RI02 CIOI,: 47K .0018 c102.:. .0056 - -ElCT.2 LEFT

31、 CH. PH. INPUTS 4 .005 : ROUT - RFEED BACK RIN SW-2 . . R?, 5.61 -= I -= 3 4 7 OECK2 FRONT . SW-4 -1L.J!. e- . ? -E - - . 4: FILTERSW, MONO MODE STEREO OUT TAPE Si. IN - r -1 C C 103 .004 f O Rl05 Ill - 5.6K 18 11; . SPEAKER FUSES Fl _2A INSTRUI FIOI 2AINSTRIJllll 0305 0306 0305 0306 ( 7TT m m TTT 5

32、0 EC B C II C 8 C 8 - SW-7 BIAS BIAS . t _j 4 i) TEST TEST . - 0 S 4 5 6 7 POINT 3 4 5 6 1 POINT r jiC- C 0303 c OS04a: 0303 c o104Q I 0 E B EQc:J E C I R E c:J C - a R309 00302 I R309 Qo302 I VOL. E B E a I COMP. o:so1Qc_z oso1Qc 1 I I R303 E 1-1 R303 E a ;J. - LIN CJ CJ /_ POWER AMI! 1001349001 PO

33、WER AMP. 100,1.349001 rm - 77 15 LOUT ONES :J ON SP.I RI07 180 l/2W C402 l 5000/30 AUDIO OUT HIGH MUTING SW, lt,iDICATOR _ 1 _ 1 ASSEMBLY 0 0 ON 1 le OFF SW-8 IC MULTIPLEX 100-1332-005 14 IC! e 12 c:J 11-t-+-+- 6 710 5 L5 Aux-.-OU_T . 4 C AUX.IN Qat -. 2 E Bc:J R6 8 rli,1 L2 ROUT R6 2.A.71/ZW SW-5 O

34、FF OFF R SPEAKERS,2 RI06 2.A.71/2W T40I POWER TRANSFORMER . :, 0 (I) 0 z R402 1.2K R403 100 .-1-,-:.:=-i-o-2_41140-030 BLK. R401 8201 N -;: 1 ., I ., ., , .:.- 12v DC SWITCHED SW-l DECK 3 REAR . luh 016-1092-011 016-1092-011 -ACCESSORY OUTLET 105120vAC 250W, MAX, 105120v. 50 60 Hz AC ONLY 16 QTY. PE

35、R UNIT 2 2 2 2 2 l l l 2 l 2 1 l 4 1 l 1 2 1 2 l 3 2 2 1 1 l 1 1 1 2 1 l 4 2 2 1 2 1 1 1 1 1 1 l 2 1 12 4 l . PART NUMBER 011-1000-003 Oll-1000-006 011-1000-009 011-1000-011 011-1000-012 011-1000-058 011-1000-060 011-1006-033 Oll-1004-022 011-1006-033 011-1008-003 012-1023-002 012-1025-002 013-1030-

36、002 013-1031-007 015-1060-006 015-1060-003 015-1060-005 015-1061-007 016-1092-011 017-1095-010 018-1100-032 018-1100-033 018-1100-034 018-1100-035 018-1102-087 018-1104-008 018-1105-066 020-1111-003 021-1120-010 021-1120-018 021-1120-023 021-1120-026 021-1120-031 021-1120-042 021-1121-014 021-1121-0

37、58 021-1121-023 021-1123-033 021-1125-011 023-1137-043 023-1138-013 024-1140-030 026-1156-001 0281165017 028-1166-114 028-1166-143 030-1181-021 030-1189-008 030-190-006 342-C PARTS LIST pESCRIPTION Ceramic Capacitor Ceramic Capacitor Ceramic Capacitor Ceramic Capacitor Ceramic Capacitor Ceramic Capa

38、citor Ceramic Capacitor Electrolytic Capacitor Filter Capacitor Tubular Capacitor Mylar Capacitor Zener Diode Bridge Rectifier Speaker Fuse Fuse, Slo-blo Input Jack Input Jack Input Jack, Phone Jack Coil Meter Single Knob Rear Knob Front Knob Tuning Knob Panel Panel Inlay FM Dial Power Transistor 1/

39、4 Watt Resistor 1/4 Watt Resistor 1/4 Watt Resistor 1/4 Watt Resistor 1/4 Watt Resistor 1/4 Watt Resistor 1/2 Watt Resistor 1/2 Watt Resistor 1/2 Watt Resistor Stand-up Resistor Potentiometer Rotary Switch 7 Section Switch Power Transformer Line Cord Carton Filler Filler 6 Post AMP Connectors Bulb S

40、ocket 17 CC-.005 CC-.0018 CC-.0033 cc-.oo47/l.4KV CC-.0056 cc-.680 cc-.00111/4KV CEIM-50/15 CEIM-50/15 CMM-.22/250v DZ-13 F-AGX-2 F-SBl 1/4 J-2-D j-2-Q .J-2-T J-3-ST-8 L-RF-1S M-SS-11 QP-11 RCll-100 RCU-470 RC11-l.2K RCU-2.2K RC115.6K RCU-47K RC21-180 RC21-820IC RC211K RWS-1S2X2 RCVlOKPH WP-6 , CTHH

41、 . CTFHHl VPL184?- XPLU47 . QTY. PER UNIT 3 1 2 1 1 1 1 1 -4 4 1 1 1 . 14 1 1 1 1 l 1 1 1 1 1 1 1 1 1 1 1 . 2 1 PART NUMBER 030-1190-012 030-1192-001 030-1192-002 030-1193-001 030-1194-003 030-1370-001 031-1197-023 031-1198-013 031-1200-001 031-1203-001 031-1209-011 031-1212-001 031-1241-002 031-136

42、0-001 032-1250-206 032-1250-207 032-1250-209 032-1250-219 032-1250-220 032-1250-203 032-1251-103 032-1251-104 032-1252-091 032-1252-092 032-1252-093 035-1275-001 100-1330-015 100-1331-013 100-1332-005 100-1333-013 100-1349-001 100-1333-013 342-C PARTS LIST DESCRIPTION Socket Fuse Post w/washer & nut

43、 Fuse Post Transistor Socket AC Outlet, Red Indicator Assembly Dial Cord Dial Pointer Plastic Feet Nylon Pulley Spring Deflector Fly-wheel Assembly Nylon PC Stand-offs Power Supply Brkt. Switch Mtg. Brkt. Diffuser Brkt. Pulley Brkt. Pulley Brkt. Tone Control Brkt. Bottom Cover Top Cover Rear Chassis Main Chassis Front Chassis FM Antenna Front End Assy. IF Board Assy. Multiplex Board Assy. Pre-amp Board Assy. Driver/Power Board Assy. Tone Control Board Assy. 18 X-PLU-10 XF-3AG XFHJM X-Q-3 X-AC-SAR A-FT-1 A-PY-3/8 H-cs-4 A-X-40 A-FW-B Assembly ZANTFM-2 .