Scott-355R-375R-385R-Service-Manual 电路图 维修手册.pdf

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1、Setlice Manual AM/FM Stereo Receivers 355R 375R 385R SCOTT The Name to listen to. H. H. SCOTT, INC., 20 Commerce Way, Woburn, Mass. 01888 Tel. (617) 933-8800 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 CONTENTS PAGE 1. Specifications and revision information. 3. Circuit description, tuner sectio

2、n. 4. Circuit description, tuning indicators. 6. Circuit description, audio amplifier. 7. Circuit description, protection and power meters. 8. Circuit description, temperature sensors. 8. Test procedures. 11. Fluorescent indicator panel lead codes. 14. Parts location diagrams. 17. Circuit diagrams.

3、20. Exploded view and Notes. 21. Parts list. 32. Troubleshooting guide. CAUTION NOTICE The following safety precautions must be followed to assure continued reliability and safety against fire and shock hazard: 1. Replacement parts used during servicing of this appliance must have identical characte

4、ristics as those offered and recommended by H. H. Scott, Inc. In the interest of continued product safety we refer in particular to those safety critical components shown on the Replacement Parts List identified by the IEC Symbol A . 2. A dielectric test is to be performed on each appliance followin

5、g the re-assembly and before returning the unit to the customer. 3. The dielectric test to be performed on H. H. Scott, Inc. electric components serviced in the United States and Canada for use in these countries shall consist of not less than the following:* l) A dielectric tester designed to have

6、an output voltage that ( l) has a sinusoidal wave form, (2) has a frequency that is within the range of 40-70 Hz, and (3) has a peak value of the waveform that is not less than 1.3 and not more than 1.5 times the root- mean-square value. la) The sensitivity of the test equipment shall be such that w

7、hen a 120,000-ohm resistor is connected across the output, the test equipment does not indicate unacceptable performance for any output voltage less than the specified test voltage, and does indicate unacceptable performance for any output voltage equal to or greater than the specified test voltage.

8、 The calibrating resistor is to be adjusted as close to 120,000 ohms as instrumentation accuracy can provide, but not more than 120,000 ohms. 2) The tester is to be connected per the instructions enclosed with the instrument, or as follows: a. The tester is connected to the power line receptacle and

9、 the power switch is turned on. b. Sufficient time is allowed for the tester supply to stabilize and then the output voltage is adjusted for 1080 V. c. Leads of the tester, usually marked GND and HV, are connected between chassis ground and both blades of the male plug of the power cord. d. Switch t

10、ester to test and observe leakage indicator. *Dielectric tests made by service personnel in countries other than USA and Canada must use test equipment and procedures specified by the safety agency serving that.country. COPYRIGHT H.H. SCOTT ELECTRONICS Printed in U.S.A. 11/82 029-1175-049 H.H. SCOTT

11、 ELECTRONICS, Scottkitand Scotsman are registered trademarks of H.H. SCOTT, Inc. RadioFans.CN 收音机爱 好者资料库 SPECIFICATIONS AMPLIFIER SECTION 355R 375R 385R Minimum Continuous RMS Output - t:- power perchannel both channels driven into 8 ohms 45W 65W 85W from 20 Hz to 20 kHz With no more than rated T.H.

12、D. Total Harmonic Distortion 0.050Jo 0.040Jo 0.030Jo at rated output Total Harmonic Distortion 0.040Jo 0.030Jo 0.030Jo at 10 Watt from 20 Hz to 20 kHz Intermodulation Distortion at rated 0.040Jo 0.030Jo 0.030Jo output power; 60;7000 Hz;4: 1 Signal to Noise Ratio, shortened input, IHF-A network: Phon

13、o (lOmV, RIAA 1 kHz): 81 dB 84 dB 84dB Others 100 dB lOOdB lOOdB Input Sensitivity Phono MM 2.5mV 2.5mV 2.5mV PhonoMC 0.25 mV 0.25 mV Others 150mV 150mV 150mV Phono Overload 200mV M.M: 220mV M.M: 220mV M.C: 20mV M.C:20mV Damping Factor, 1 kHz, 8 Ohm more than 50 60 60 Channel separation at 1 kHz PHO

14、NO 55 dB 55 dB 55 dB at 1 kHz OTHERS 65 dB 65 dB 65 dB Frequency Response at 1 Watt output Phono RIAA 20 Hz-20 kHz: 0.5 dB 0.5 dB 0.5 dB Others 20 Hz-20 kHz: 1 dB 0.8 dB 0.8 dB Filters subsonic 6 dB/octave, - 3 dB Phono 18 Hz 30 dB/oct Phono 18 Hz 30 dB/ oct Phono 18 Hz 30 dB/oct - Hi Filter 6 dB/oc

15、tave, - 3 dB 7 kHz 12 dB/oct 7 kHz 12 dB/oct 7 kHz 12 dB/oct Others 18 Hz 18 dB/ oct Others 18 Hz 18 dB/ oct Others 18 Hz 18 dB/oct Tone Control Range Base at 100 Hz lOdB lOdB lOdB Treble at 10 kHz lOdB lOdB lOdB Mid: at 1 kHz 6dB 6dB 6dB Loudness Contour Volume control set to-30 dB at 10 kHz + 3.5

16、dB at 10 kHz + 3.5 dB at 10 kHz + 3.5 dB at 10 kHz at 100 Hz + 7 dB at 100 Hz + 7 dB at 100 Hz + 7 dB at 100 Hz GENERAL Power requirement: 120V AC; 60 Hz 120 V AC: 60 Hz 120 V AC: 60 Hz (Refer to rear panel for specified voltage_ and frequency before making any connections.) Power Consumption 280W 3

17、70W 480W Dimensions (W /HID) 5/20/13, 5 /20/13 , 5/20/13, 125mm/500mm/330mm 125mm/500mm/330mm 125mm/500mm/330mm Net Weight 25 lbs. 11.5 Kgs. 28 lbs. 12.7 kgs. 30 lbs. 13.0 kgs. SPECIFICATIONS FM SECTION 355R 375R 385R Tuning Range 87.5 to 108.5 MHz 87.5 to 108.5 MHz - -=-5 to 108. 5 MHz IHF sensitiv

18、ity 10.8 dBf/1.9uV 10.3 dBf/1.8 uV 10.3 dBf/1.8 uV 50 dB quieting sensitivity Mono: 16.7 dBf/3.8 uV Mono: 16.5 dBf/3.6 uV Mono: 16.5 dBf/3.6 uV Stereo: 37 dBf/39 uV Stereo: 37 dBf/39 uV Stereo: 37 dBf/39 uV S/N ratio at 65 dBf Mono: 72dB Mono: 76dB Mono: 76dB Stereo: 67 dB Stereo: 70 dB Stereo: 70 d

19、B Distortion at 65 dBf Mono: 0.150Jo Moho: O.IOJo Mono: 0.1 OJo Stereo: 0.250Jo Stereo: 0.20Jo Stereo: 0.20Jo Frequency response + ldB/ - 2dB 20Hz-15 kHz 20Hz-15 kHz 20 Hz-15 kHz Capture ratio 1.2 dB 1.2 dB 1.2 dB Alternate channel selectivity 60dB 60dB 60dB Image rejection 75 dB 80dB 80dB Stereo se

20、paration at 1 kHz 45 dB 50dB 50dB Spurious response rejection 78dB 78 dB 78 dB Subcarrier rejection 55 dB 60dB 60dB IF rejection (98 MHz) 90dB 90dB 90dB AM SECTION 355R 375R 385R Tuning Range 515 to 1640 kHz 515 to 1640 kHz 515 to 1640 kHz Usable sensitivity (bar ant.) 250uV/m 250uV/m 250uV/m S/N ra

21、tio 50dB 54dB 54dB Selectivity (1MHz) 45 dB 45 dB 45 dB - Image rejection 50dB 50dB 50dB REVISIONS MADE DURING PRODUCTION 355R,375R I) R203 (FM IF CKT) deleted in certain production units to improve stereo separation. 2) R 502 (Pwr. Supply) changed from I.OK to 220 ohms. 3) Pwr. transformer secondar

22、y voltage increased to provide better regulation and to accommodate additional voltage drop by added 4.7ohm resistor (R510). 4) CR5 l l changed from 1214 to 1215 to provide higher supply to tuner section. 5) C218 increased from 1/50 to 10/15 to reduce trancient when unit switches in and out of MUTE.

23、 6) Q601 changed from KSA733Y to KSA708Y to improve reliability. 7) C602 changed from 4.7/50 to 4.7/160 to improve reliability. 8) CR602 deleted. 9) Q501 changed from KSD 288-0 to KSD 288-Y to reduce voltage drop. 10) R602 changed from lOK to 2.2K. 11) C513 changed from 220mF to IOOOmF to reduce pro

24、tection circuit triggering with tone controls set at boost. 2 CIRCUIT DESCRIPTION -Tuner FM Front End The input section is designed using a balun coil that provides input matching for both 75 and 300 ohm transmission lines. The tuner section uses a MOSFET RF amplifier (QI), trans- former coupled to

25、a bipolar mixer (Q2) for conversion. The local oscillator (Q3) is capacitively coupled to the base of Q2 where through the hetrodyne process a 10. 7 MHz signal is produced for IF amplification. FM IF Amplifier Jilili1 Ill rl1 lll 1111 !I II II rtJ 11 tl1 tll 11111 lll lil ii ii :rll I I I I L 0.005

26、0.05 0.1 Q.5 1.5 3 7 15 50;:i_ R-J-l-1-1-1-:-I- 1-1-W/8 SC 0.0015 0.05 0.1 0.5 1.5 3 7 15 50 111 ll rllill I! ll 11111li1IIJ, 3 7 15 50 J FL 801 R aoo5 - I I I I ,; 11()1? 0.05 Q. I 0.5 1.5 .:, 7 cooo I 23 31 32 33 , TYP. BG-32, BG-60 3SSR-37SR .I, I.) Sr s 53 S.c TERM. iW. 1 2 3 4 5 6 7 8 Q 10 11 1

27、2 1 3 14 15 16 17 18 1 9 20 .; ELECTRODE F G Pl P2 P3 P4 PS Pt Pd PA PB PC PD G PE PF P% PW Ps Ps B 4 3 TERM. NO. 21 22 23 24 25 26 27 23 29 30 31 32 3 34 35 36 37 38 39 40 ELECTRODE Ps Ps Let- p p G Pl PJ PK PL P+p 17 p-bi1t12_t F 2 1 Reh G H. Met 0ot 1 -_. _ .,_ -. l nmi11-J llTlTTTr, 1 u 11 l -1

28、I i I . i I i l I ,-r r-I I I I I I I I I I i I I I I I I I I i 1 FL-701 385R v1,i;, -worulil6!i6l . JnllihbU!i-di , , .,-. :,_sll.-:-:-.:dc:-.i: 1s-_ r:,H en ./ , 011 ooo- r=:, t J I rcuoo c:iCJi-J ,- -J l- - h . ; -iL_g Aoooo Br , cr-j nc=J Ec:=1-Jr-1 OrJD i.L-:Jc.J. c.:1c=1ist=-=1 1:.:., LC - - L

29、 h de;. C, _,_d8zo-:-i4 :-.: 1 10-r-;.,.:-_-,s-f -:-:;4-=j;2-:=-1.o:-t-T.Jl:f-+6il.-;-t 8 Meta - +e MeT_ -0 1-iczd=-nooo . ,-, r-i .-, c:1c-; Ofl-J-,-:r- c-r-, ,-, r-1 R h , - . coo c-11r-.4 _ c:Sc=:i lr:=-1600 oCJCJbc.:.c_:-_:_=-=-:=1 . C -c Reh / .Ll ,._, -.-J l-.- -. L t-,._ I _ J - ,l- - !:li No

30、.-rr. -ttT-:i:-= 11i). . 57.() 0 - O , . s-o l. 5 (0 . O C C . 0 . l ;.-. n 1 I I ( ( ,-I r, 6 4 _ .r,:_., -/: 1-1.- (J. -Tr-w 1 -11r-rl - l _ -I - -I I II I I l 1 l ! I ll I ) 53 5:z 51 (. , I I 1 I, _, Ii t - 11 !7 I . I , ;7 , /j u 11 n 1rn - n Jn jri n n ii ri 8 i g -;, , i ; n J ; . 40U :wa:rrs

31、 :o:om :n:mm C=:J c._=i c:J 1-=:J c=i L.:.J c:u:-=:rc:.L:.:._J rsn. 0/ - t J c:J C=:J C=:J c=:J r=:J,moo Clc:=J ooc=:i =:=J 1Lch /O_ooo r=:i c=J c:J c=:i. r=i c:J CJt:=1.CJc:J_c=i c=J. : dB. ,-12014.:.-10 -8- .:.5:.; _ 4:fz:Lo_Ol 4,:fo-+8- Metal ,-or-no-c:=J-c:J c=:n=:n:=rc:n:moa-c;c:J c:ic:i i:=:rc

32、:=:J r h l-1. o _ ooo -.c=:l-i=:i _ c=:l. .c:=:I . c:L.c:.i. on Q o_.c:; :l_ c:i CJ _c:=J-1.-=:i KC . _watts =-c=:J .L.J. c:=J , c:J c=1 r=:1:c:J.J:=i._E.:J _ s n -. -. -. -. _ 1 ;, . . . C,.) FL 802 315R-385R zq-cc; zcr zr, ,r:,- ,r1 , ,er rrr -n -=-I _ up ,er _ ._ s, ! :;_ t f I. . a J._ I, a! b N

33、 Nf hJ c hz a, _, J, :f, _b,_ If_, ! _ ,/c ,vf ,.;?_ P,.,m 6175 q 1J 1, l;J7al1.Li.1. r, 65 L, 1,3 t, 60 57 JJ 57 56 1i 01 i 5Z , o r _ 3 6 5 # 312 _, 11.,31, SI ,- 1 ss I s4 ss- 1 I - SG!lAL 4 OD I IFVil TUrr!lNG i/tl t/0 .L 2 J - _:,_ 6_ _7_ .3_ 7_ (0. u_ ti -_.) 0 - 0 , - c.(pJ ctp 2 - uvu uir ff

34、) fA /; 1/Jn u 1 M11 0 rw n.J1 7 ,) IA lflJ,J /J 14-/j !l I - ,_ lf (,t e., tq lf3 - j3 2JUIT RIDS AII/Flil SIGNAL IIETDI ADJUST Atltll L014NtL Lo. END OF POWER IKTIJf ADJUST R883 L-CHAHICL HIGH END OF POWU 1111:TtR -ST 11877 RCHANNL LOW DI OF POWER lilTEt AO.IUST Rm2 R CHANNEL HIOH /Cl Of POwtR llt

35、TR ADJUST IU412 L-CHANNEL IOU CURRENT ACIJUST RM62 RCHANMlL IDLE CURliElff ADA/ST LEDS CRSOI SUMO IN.ICATOR(RED) CRSIZ: DIAL POINTER IREDJ CA603: SAFETY INDICATOR IMDJ CA ! .,., Ton I . , I 11 1 =-.ij -_ ?iif: !J Iii ,1 . ! . I I LL . ,. I -a I 13014-526310 FL 801 BG -32 SWITCHES $WI fINCTION (4ll.f

36、ll,PHONOM_M AUICI Al.D(2l SW2 TAPE (COPY,HORlo!ALJ SW3 TAPE ITAPEI, TAPE2) SW4 TAPE SOURCE, MONITCAJ SW! MODE fil!lil, MONO) SW. . . L-=L_._,c,-c,OCY,v;:;:;:;.t=-=-=J=-=M.rX,CWH.:,.,_-,.,-,=,d,u=-,c.ti4,.,.,=:-wVvvv-v, . ,_, :,:,., . ,.-,2.c- . .I- co OJ oro 0 _; -_ L(J oo H -., -,., . ,)! 0 I 1)1-

37、1 J 11,:r:f: ii - CD CD ID () rTt7 It L It L ru.n 11 -. I L L i-:1 INJ :r: -.J lT1 (J1 :c Ci 0 l G) :c l il i CJ) () J: rr, s: () 0 - ) G) :0 ) s: (,JJ 0) 01 :0 l . NOTES 1) Many transistors used in these models are identified by KS in place of the more familiar 2S prefix. Generally these parts are

38、electrically interchangeable. However, when replacing the SMALL SIGNAL devices, please observe proper transistor basing. 2) Pushbutton switch banks are available as a complete assem- bly or as individual sections. It is suggested that individual sections be replaced rather than the entire assembly.

39、There- fore when ordering, specify both part number for assembly and describe individual section by its front panel function. 3) When ordering replacement parts please give complete in- formation as listed in the parts list section. In addition, please note the unit model number. 4) Power transforme

40、r part numbers may vary from those listed here, therefore please give part number of old transformer as well as all information from parts list herein. 5) Input power of typical unit, properly adjusted at 120V line, volume minimum, switched to FM is 35 watts, 0.5A. 20 (I,; . /) lp;!I - M _ 111 r rs1

41、l- - . , Cl w Cl 0 _J a. w a: J; ,.)_, .Yt - c;, II LO CX) () I-4 jJ J. qyf t!) z 5: I- v, _J - -(;l_ _ : -, . I Y5 d . 0 l_/l ,J -_ _, -,_,_-_ -:._y -r- _ ) ) REPLACEMENT LIST OF MECHANICAL AND ELECTRO MECHANICAL PARTS- REFER TO 385R EXPLODED VIEW -:- - SYMBOL PART NO. DESCRIPTION SPECIFICATION USE

42、DIN 1 6102-502-8101 CABINET l.0T VINYL STEEL ALL 2 6103-500-3107 SIDE-CABINET-L 15T PLYWOOD VINYL ALL 3 6103-500-4102 SIDE-CABINET-R 15T PLYWOOD VINYL ALL 4 7334-500-1106 WASHER-CABINET P.PBLACK ALL 5 6804-502-2206 SP ACER-CABINET 1.0 HIMERONE SHEET ALL 6 6022-505-6107 CHASSIS-BOTTOM l.0T SPC-1 FZY

43、ALL 7 6074-500-2101 FOOT RUBBER ALL 8 7702-507-7100 PANEL-FRONT ALEXTRU 355R 8 7702-507-7207 PANEL-FRONT ALEXTRU 375R 8 7702-507-7304 PANEL-FRONT ALEXTRU 385R 9 6463-500-7106 GUIDE-KNOB F ABS GREY ALL 10 7714-504-7207 PLATE-BACK VOL. 0.8T ALS ALL 11 7603-502-1109 MASK-TUNING ABS GREY ALL 12 7724-507

44、-7104 KNOB-TUNING ALBALUMITE ALL 13 7724-505-6103 KNOB-ROTARY ALBALUMITE ALL - 14 7724-506-0106 KNOB-BALANCE 94HB ACRYL CLR ALL 15 7724-503-7108 KNOB-VOLUME ALBALUMITE ALL 16 7653-501-4106 DIAL WINDOW 5.0T ACRYL CLR ALL 17 8012-504-1106 SCALE-DIAL 0.5T ALS OFFSET 355R 17 8012-504-1203 SCALE-DIAL 0.5

45、T ALS OFFSET 375R 17 8012-504-1300 SCALE-DIAL 0.5T ALS OFFSET 385R 18 8014-502-7104 BLIND-SCALE ACRYL 0.5T x 373 x 13 ALL 19 8012-504-0208 SCALE-BACK l.0T SPC-1 MET GRY 355R 19 8012-504-0101 SCALE-BACK l.0T SPC-1 MET GRY 375R 19 8012-504-0305 SCALE-BACK l.0T SPC-1 MET GRY 385R 20 6834-506-6103 SPACE

46、R RUBBER3.5T ALL 21 8003-500-4101 CAP-POINTER ABSBLK ALL 22 7 654-503-3104 FILTER-WINDOW ACRYL0.5T 355R 22 7653-503-0102 FILTER-WINDOW ACRYL0.5T 375R 22 7653-503-0209 FILTER-WINDOW ACRYL0.5T 385R 23 0859-141-6008 TEFLON TAPE W 25.4 X 33Y X 0.8T ALL 24 6613-506-1105 BRKT-GUIDE PNTR 0.8T SPCY-1 FZW ALL 25 5104-509-1100 SHAFT-TUNING MBR2GC10 ALL 26 6603-500-6107 HOLDER-LED,S ABS NATURAL ALL 27 6614-583-2106 BRACKET, SCALE, R l.0T SPC-1 FZW ALL 21 SYMBOL PART NO. DESCRIPTION SPECIFICATION USEDIN 28 5214-501-3104 PULLY GUIDE PA WHITE :- ALL - 29 7394-500-5106 SHAFT GUIDE FEFZY ALL 30 6