Realistic-STA95-rec-sm 维修电路原理图.pdf

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1、ruLtstd.SerulceamuaISTA.95AM /FM STEREO RECEIVERCatalog Number: 31 -2082cusl0M MANUFACTURED FoR BADIo SHACKEn ovstoN 0F rANDy coRponAloNRadioFans.CN 收音机爱 好者资料库CONTENTSpage1. SPECIFICATIONS 3&42, BLOCK DIAGRAM . . .53. DISASSEMBLYINSTRUCTIONS .64, DIAL STRINGING DIAGRAM. .65. ALIGNMENT PROCEDURE. ,7

2、_96. ALIGNMENT & CHECK POINTS . . . . .107. LEVELDTAGRAM. .119. 0062 TUNER BOARD . 18& 1910. 5042 PRE-AMP BOARD. .2011. 6052 MAIN-AMP BOARD. .2112.7159INPUTBOARD. .:.2213. 8034 POWER SUPPLY BOARD ,.,2314. 9035 TONE CONTROL BOARD . . . , . .2415. SEMICONDUCTOR LEAD IDENTIFICATION ,.,2516. ELECTRICAL

3、PARTS LIST . . 26 _ 3317, MISCELLANEOUS PARTS LIST . . 34 &3518. SCHEMATIC DIAGRAM. . SEPARATE SHEET19. EXPLODED VIEW. . SEPARATE SHEETRadioFans.CN 收音机爱 好者资料库SPECIFICATIONSNOMINALLIMITUN ITFM SECTION1, TUNING COVERAGE2. DIAL CALIBRATION ACCURACY 90 MHz98 MHz106 MHz3. USABLE SENSITIVITY(NOtSE & DTSTO

4、RTION -30 dB)4, IMAGE REJECTION (at 106 MHz)5. lF REJECTION (at 90 MHz)6. FULL LIMITING (at _3 dB)7. lF BANDWIDTH (6 dB down)8. DISTORTION (1 mV INPUT)9. SIcNAL-TO-NOISE RATIO (1 mV INPUT)10. DE-EMPHASIS 75 psec. (at 50-10,000 Hz)11. DISCRIMINATOR BANDWIDTH (Peak-to-Peak)12. AFC HOLDING RANGE (with

5、1 mV signal)13. OUTPUT VOLTAGE MONO(at 75 kHz dev., 400 Hz mod., 1 mV input) STEREOMUTING THRESHOLDOVERLOAD, THD at 98 MHz, 100% mod.(100 mV RF input)SPURIOUS RESPONSE at 98 MHzANTENNA INPUT 3 pV. 1 12F,103.35 MHzCAPTURE RATIO (1 mV INPUT)ALTE RNATE CHANNE L SE LECTIVITY(0.1 mV input)100 Hz1 kHz10 k

6、Hz87.5 - lo8lII2.O5.0 |50 I802.o I03 I65t1.5 I400 Il.2SO0.75o.7l,l80,5014.15.16.17.18.MPX SECTION1, STEREO SEPARATION(10096 mod., 1 mV input)2, DISTORTION 1 KHZ(100% mod., 1 mV input)3. STEREO BEACON SENSITIVITY (pilot 7%)4. RESIDUAL 19 kHz & 39 kHz (1 mV input)5. SUPPRESSION OF SCA INTERFERENCE(1 m

7、V input)AM SECTION1. TUNING COVERAGE2, DIAL CALIBRATION ACCURACY 600 KHZ1,000 kHz1,400 kHz3. USABLE SENSITIVITY(400 H2,30% mod.600 kH2,1000 kH2,1400 kHznoise & distortion-20 dB)4. IMAGE REJECTION (at 1,400 kHz)5. lF REJECTION (at 600 kHz)6. AGC FIGURE OF MERIT(from 100 mV/m at 1,000 kHz)RadiatedDire

8、ct7, DISTORTION(400 H2,30% mod., 5 mV/m input)3840300.51050510 - 1660250253530451.588 - 108t250t2SOt3503.09.045703.0t 1S00.860t2300t4000.7b t 2 dB0.65 t 2 dB4-161.51.23-164040520 - 1620t1bt30t40703.540273220500403025302.5MHzkHzkHzkHzpVdBfdBdBpVkHzo/,/odBdBkHzkHzVVpVo/odBdBo/opVdBdBdBdBdBdBkHzkHzkHzk

9、HzpY lmpVdBdBdBo/oNOMINALLIMITUNIT8. lF BANDWIDTH (6 dB down)9. OUTPUT VOLTAGE(400 H2,30% mod., 5 mV/m input)10. AUDIO RESPONSE(5 mV/m input from 50 Hz to 2 kHz, 0 dB 1,000 kHz)11. SELECTIVITY 200 pVlm12, SIGNAL-TO-NOISE RATIO(1,000 kHz, with antenna input 5 mV/m)13. AM BEAT (input 100 mV/m)AUDIO SE

10、CTION1, RMS OUTPUT POWER(distortion 0.3%,20 Hz - 20 kHz)PER CHANNEL DRIVE 8 O4aBOTH CHANNELS DRIVEN B s24a2. IM DISTORTION(at 30 W output 7O/7,OOO Hz 4l1l3. HARMONIC DISTORTION (at 30 W output)100 Hz1,000 Hz10,000 Hz4, FREOUENCY RESPONSE(AUX, 8 Sl load, 1 W output) 30 Hz - 20 kHz5. INPUT SENSITIVITY

11、 (for 45 W output)PHONOAUXTAPE MONITORPHONO MAGAUXTAPE MONITORBASS 100 HzTREBLE 10 kHz8. EOUALIZATION RIAA: 30 - 15,000 HzL PHONO AMP OVER LOAD CAPABILITY (at 1% HD)10. HIGH FILTER 10 kHz11. LOW FILTER TOHz12. LOUDNESS COMPENSATION (Volume -30 dB)10 kHz100 Hz13. CHANNEL SEPARATION(AUX input 100 - 10

12、,000 Hz)14. SIGNAL-TO-NOISE RATIO (input shorted)6. INPUT IMPEDANCE7. TONE CONTROL15. RESIDUAL NOISE16. LOAD IMPEDANCEPHONO MAGAUX120 Volts, 60 Hz AC*23 WATTS, No Signal190 WATTS, Full Signal* 22Ol24O V AC, 50 Hz for European and Australian Models250t12.5160160507070r10t10-42840505248510.10.10.1o.21

13、50-6-64I4065801.0146-2000.30.150.150.3t 1.53160 t 30160 t 30!10!2t1Ot2RIAA t 2100-Gt2-Gt24x29t2354-16-62032104649454758703kHzmVdBdBdBdBdBmVOHMdBo/oWWWWo/,o/oo/oo/odBmVmVmVks2koks2dBdBdBmVdBdBdBdBNOTE: Nominal Specs represent the design specs; all units should be able to approximate these-somewill ex

14、ceed and some may drop slightly below these specs. Limit Specs represent the absoluteworst condition which still might be considered acceptable; in no case should a unit performto less than within any Limit Spec.BLOGK DIAGRAMldssullVldssul)v)oI lstft4?*? o-tt-x= :=ErE -.?2 zA =E f E ;= 6-x-a-o-j=!tz

15、ri-jqJti;5;FerI=ry=EtttrNvHJ lHS18IfNXVH IIIDISASSEMBLY INSTRUCTIONS1. Removing chassis from Wooden Cabinet. (Refer to Fig. A)Remove five screws (#88 & #91) from sides and back.2. Removing the Front Panel. (Refer to Fig. A)a) Pull off the SPEAKERS, BASS, TREBLE, DUBBING, MONITOR, VOLUME,BALANCE, SEL

16、ECTOR and Tuning knobs.b) Remove five screws (#90) from top and bottom of Front Panel.Figure Aa,-rd-ffi-.- I -(82) .8 .-t-v)DIAGRAMfully closed position.6DIAL STRINGINGNote: Tuning capacitor should be in-oALIGNMENT PROCEDURESDo not attempt alignment unless the following equipment is available.1. AM

17、Signal Generator2. Oscilloscope3. AC Voltmeter4. FM Signal Generator5. Stereo Modulator6. Audio Generator7. Distortion meter8. DC Voltmeter9. Frequency CounterNote: Bemove line cord antenna from FM external antenna terminal when aligning.AM IF & RF ALIGNMENTNote: Remove line cord antenna from FM ext

18、ernal antenna terminal when aligningRECEIVERL451TAPE OUTOutput of signal generator should be no higher than necessary to obtain an output reading.Signal Generator Modulation: 30%.Set SELECTOR switch SW1 to AM.STEPSIGNALGENE BATORCOUPLINGSIGNALGENERATORF R EOUENCYRECEIVERDIALSETTI NGINDICATORADJUSTME

19、NTRefer Fig. 4.REMARKS1Refer Fig. 1455 kHz(400 Mz Mod.)Point of non-i nterference(on/about600 kHz)AC Voltmeterto TAPE OUTjackT401 flFT)Adjust for maxi-mum reading.2Same as Step 1600 kHz(400 Hz Mod.)600 kHzSame as Step 1L401L451(OSC Coil)(ANT Coil)Same as Step 13Same as Step 11400 kHz(400 Hz Mod.)140

20、0 kHzSame as Step 1TC1 05(OSC Trimmer)TC1 04(ANT Trimmer)Same as Step 14Same as Step 11000 kHz(400 Hz Mod.)1000 kHzSame as Step 1VR402Adjust for 250mV Audiooutput.5Same as Step 1i000 kHz(400 Hz Mod.)1000 kHzReceive rsSIGNALMeterVR4O1Adjust for 70o/oreading of fullscale with inputof 5 mV/m.Fig. 1 AM

21、ALIGNMENT CONNECTIONIIFM RF AND IF ALIGNMENTFor European model, the lowest frequency of FM tuning range should not be below 87.5 MHz.125a (1 12.5s,)Zin = 50o (75s)Zout = 300O (balanced)FM Dummy Antenna to 300O antenna terminalFig.2 FM DUMMY ANTENNABSignal generator output should be no higher than ne

22、cessaryto obtain an output readingSet Selector switch to FM.Signal Generator deviation: 75 kYzNOTE: Be sure to disconnect FM line cord antenna during alignment.STEPSIGNALGENERATORCOUPLINGSIGNALGENE RATORFREOUENCYRECE IVERDIALSETTINGINDICATORADJUSTMENTRefer Fig. 4R EMAR KS1Connect to FMAntenna Termi-

23、nal throughFM DummyAntenna(300St) Fis. 290 MHz(400 Hz, Mod.)90 MHzAC Voltmeterconnected toTAPE OUTjackL1 04(FM OSC Coil)Ll 01(FM ANT Coil)Ll02(FM RF Coil)Adjust formaximumreading onAC Voltmeter2Same as Step 1106 MHz(400 Hz, Mod.)106 MHzSame as Step 1TC1 03(FM OSC Trimmer)TC1 O1(FM ANT Trimmer)TC1 02

24、(FM BF Trimmer)Adiust formaximumreadi ngRepeat steps 1 & 2 until no further improvement is possible3Same as Step 190 MHz(400 Hz, Mod.)90 MHzSame as Step 1T1O1 (FM IFT)Adjust formaximumreadi ng4Same as Step 190 MHz(400 Hz. Mod.)90 MHzTUNING MeterT201 (Bottom)(Discriminator)Adjust forcenter point onTU

25、NING meter5Same as Step 190 MHz(400 Hz, Mod.)90 MHzDistortionMeterconnected toTAPE OUTjackT201 (Top)Adjust forminimumd istortion6Same as Step 198 MHz(400 Hz, Mod.)98 MHzReceive rsSIGNALMetervR202Adjust for 70o/oreadi ng of fu I Iscale with inputof 1mV7Same as Step 198 MHz(400 Hz Mod.)98 MHzOscillosc

26、opeconnected toTAPE OUTjackVR2O1Adjust so outputjust appears withan input signallevel of 5 pV.1 50s2of Receiver.MPX ALIGNMENTFM ANTENNATERMINAL(s00 s)Fig.3 MPX ALIGNMENT CONNECTTONTAPE OUTRECEIVERIIIFM SIGNALGENERATORFM DUMMYANTENNA300 slSet SELECTOR Switch to FM.Tune for 98 MHz on band.Signal Gener

27、ator output level : 1000pV. Deviation: 75 kHz, at 100% modulation of composite signal.connect Signal Generator to FM Antenna Terminal through FM Dummy Antenna (300 o).STEP19 kHz(PILOT SIGNAL)MODULATIONLevelSIGNALGENERATORFreq. Set toOUTPUTINDICATORConnected toADJUSTRefer Fig. 4ADJUSTFORNOTE18%Compos

28、ite 1 kHzR channelAC Voltmeter toTAPE OUT jackof R channelAdjust input foraudio output ofabout 0.65 V28YoComposite1 kHz L channelAC Voltmeter toTAPE OUT jackof R channelVR3O2MinimumAC Voltmeterreading shouldbe at least 32dB below readingin step 1.38%Composite1 kHz R channelAC Voltmeter toTAPE OUT ja

29、ckof L channelVR3O2MinimumSame as Step 2.4PI LOT OFFCarrier onlyFrequencyCounter Connectto TP (#18 pin)of PCB 0062 andgroundVR30119 kHzlf you did not obtain -30 dB readings in steps 2 and 3 (compared with step 1), readjust VR302 until you obtain -32 dBreading for both steps 2 and 3.MAIN AMPLIFIER AL

30、IGNMENTINDICATORADJUSTMENTREMARKSDC VoltmeterVR601 a, bAdjust for 0.005 V - 0.01 V acrossR622 a, b (0.33 ohm) with no signal=rlr.t-tFstE=t!q!= = E E E Eg= =EES EE E EALIGNMENT & CHECK POINTS!r,JoFIooo(JF-tr|o(CEo(0CE10Fig.4SPEAKE ROUTLEVEL DIAGRAMFREOUENCY = lkHzdttr=(3lIJ(5FJoI NPUTSE LECTO B18.9V4

31、5W/ 8f,11TROUBLESHOOTINGSYMPTOMCAUSE AND REMEDY1) Receiver not operative; pilot lampdoes not light.A) Faulty AC power cordReplace the cord.B) Defect in the power switchReplace the switch.C) Broken wire in the power transformerReplace the transformer.D) Broken power fuseReplace the fuse.2l Fuse blows

32、 when power is turned on.A) Power transformer T851 defectiveReplace the transformer.B) Short in the primary or secondary of thetransformer circuitryRepair the short.C) Damaged rectifier D851Replace the rectifier.D) Short-circuit in the rectifier circuitRepair the short.E) Short circuit in power tran

33、sistor TR609a, b orTR610a, bReplace the defective transistor(s) and check circuit.3) Pilot lamp does not light.A) Defective lamp(s)Replace lamp(s).B) Disconnection in the power transformer T851tertiary windingReplace the transformer.4l Pilot lamp lights but no sound fromeither channels.A) Resistor R

34、801, R804 or R809 openReplace the resistor(s).B) Capacitor C801, C802 or C807 defectiveReplace the defective capacitor(s).C) Diode D851 damagedReplace the diode.D) Open in secondary winding of the powertransformer T851Replace the transformer.E) Transistor TRB03 (open), TR804 (short),TR805 (short) or

35、 TR806 (open) damagedReplace the damaged transistor(s).F) Diode D801 (short) damagedReplace the diode.5) A SPEAKERS do not work.A) Speaker switch SW9 defectiveReplace the switch.6) B SPEAKERS do not work.A) Speaker switch SW9 defectiveReplace the switch.12SYMPTOMCAUSE AND REMEDY7l One channel does n

36、ot work withVOLUME at maximum, with a testsignal applied to the center terminalof Volume Control VR902 of thedead channel.Defect in transistor TR901, TR902 or TR903 ofTone Amp Board 9035Locate and correct the defect.Defect in transistor TR601, TR602, TR603,TR6O4, TR6O5, TR6O6, TR6O7, TR6O8,TR609, TR

37、610, TR611 or TR612 of MAINAMP Board 6052Locate and correct the defect.Short in speaker output terminalRepair the short.Defective resistor R902, R903, R905, R906,R907, R908, R909, R917, R921,or R922ofTONE AMP Board 9035Replace the defective resistor(s).Defective resistor R602, R603, R604, R605,R606,

38、 R607, R608, R609, R610, R613 0rR615 of Main Amp Board 6052Replace the defective resistor(s).A)B)c)D)E)8) Same as 7 above but channel operateswhen test signal is applied as 7.A) Defective lC (1C501 NJM 4558D-D)Replace the lC.B) Faulty resistor R502, R503, R504, R510 orR511 of Pre-Amp Board 5042Repla

39、ce the faulty resistor(s).C) Faulty capacitor C501 or C506Replace the faulty capacitor(s).D) Defective SELECTOR switch SW1Repair or replace the switch.9) Speaker works normally butheadphones do not work.A) Headphone plug does not mate with jackReplace the plug.B) Defective resistor R651Replace the r

40、esistor.10) All the inputs work normally exceptAUX input.A) Poor contact in AUX input jackRepair or replace the jack.B) Poor contact in SELECTOR switch SW1Repair or replace the switch.1 1) PHONO input not operative.Poor contact in PHONO input jackRepair or replace the jack.Faulty SELECTOR switch SW1

41、Repair or replace the switch.A)B)121 TAPE MONITOR 1(or2) OUTnotoperative.A) Defective contact in TAPE MONITOR 1 (or 2lOUT jackRepair or replace the jack.B) Defective contact in TAPE MONITOR switch SW3Repair or replace the switch.13) FM does not operate.A) Transistor TR801 or TRB02 damagedReplace the

42、 damaged transistor(s).13SYMPTOMCAUSE AND REMEDY13) FM does not operate.l)Transistor TR801 or TR802 damagedReplace the damaged transistor(s).Resistor R801 defectiveReplace the resistor.Short circuit in Tuner B+ circuitRepair the short.Poor contact in SELECTOR switch SW1Replace the switch.Resistor R3

43、04 defectiveReplace the resistor.Capacitpr C302 defectiveReplace the capacitor.Defective transistor TR201 or lC 1C201, 1C203Replace the defective transistor or lC(s).Defective IFT T201Replace the lFT.Defective resistor R203 or R208Replace the resistor(s).Defective transistor TR101 ,TR102, TR103 0rco

44、il L101, L1 02, L103, L104 of Tuner Board0062Replace the defective component(s).Faulty lead-inRepair or replace the lead in.A)B)C)D)E)F)G)H)J)K)14) Poor multiplex separationA) lmproper adjustmentReadjust T2O1 , VR301 and VR302.(Refer to MPX ALIGNMENT on page 9)B) Transistor TR2O2, TR203, TR2O4, TR3O

45、1,TR302, TR303, TR304, TR305 or tC tC301defective.Replace the defective component(s).C) Variable resistor VR302 defectiveReplace the variable resistor.15) Stereo indicator LED does notlight.A) Defective indicator LED D755Replace the LED.B) lmproper adjustment of VR201 of TunerBoard 0062Make readjust

46、ment.(Refer to MPX ALIGNMENT on page g)C) Defective lC 1C301 or resistor R307Replace the defective component(s).16) FM volume not sufficientA) If volume of both L and R channels not enough:Front End defective, or faulty lC 1C201, IFTT201 or faulty capacitor C224, C301 of TunerBoard 0062Locate and re

47、place the defective component.B) lf sound of one channel not enough:Defective L301 (Board 0062) in case of R channel,or defective L302 (Board 0062) in case of LchannelReplace the defective coil(s).14SYMPTOMCAUSE AND REMEDY17, AM does not operate.A)Damaged 1C401 of Tuner Board 0062Replace the lC.Defe

48、ctive L4O1 , T4O1 , CF401 or T4O2 otTuner Board 0062Replace the defective component(s).Defective transistor TR401Replace the transistor.Resistor R4O2, R409 or R411 defectiveReplace the defective resistor(s).Capacitor C416 or C419 defectiveReplace the defective capacitor(s).Selector switch SW1 defect

49、iveReplace the switch.Defective tuning gangReplace tuning gang.Damaged AM bar antennaBepair or replace bar antenna.B)C)D)E)F)G)H)18) LOUDNESS has no effectA) Defective LOUDNESS switch SWSReplace the switch.B) Defective capacitor C901, C902 or resistor R904Replace the defective component(s).C) Defect

50、ive VOLUME control VR902Replace the VOLUME control.19) Stereo-Mono not effectiveA) Defective MONO switch SW4Replace the switch.2Ol TAPE MONITOR not effectiveA) Defective TAPE MONITOR switchReplace the switch.B) Poor contact in TAPE MONITOR input jacksRepair or replace jack(s).21 BASS control has no