Pioneer-SX3900-rec-sm 维修电路原理图.pdf

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1、$eftice nualFM Iuartz LockedSTEREO RECEIVERsix-3s|oo()proNEERRadioFans.CN 收音机爱 好者资料库MODEL SX.3gOO COMES IN TWO VERSIONS DISTINGUISHED AS FOLLOWS:TypeVoltageRemarksKU120V onlyU.S.A. model5 / UI 10V, 120V, 22O and 240V (Switchable)U.S. Military modelThis service manual is applicable to the KU type. Wh

2、en repairing the S/G type, please see theadditional service manual (see pages 47 -56l.CONTENTS1. SPECIFICATIONS1. spECtFtcATtoNS 2 Power Amplifier Section2 FRoNr PANEL FACILTTIES a Continuous Power 0utput 0f 120 wattsxper chan-3 BLocK DIAGRAM 7 nel, min., at 8ohms from 20Hertz to 20,0004. clRCUlr DE

3、SCRIPTIoNS Hertz with n0 m.re than 0.005% tolal harmo-4.1 FM Tuner Section 8 niC diStOftiOn.4.2 AM Tuner Section 9 To,rl Harmonic Distortion (20 Hertz to 20,000 Hertz,4.3 Audio Section 9 g ohms)4 . 4 D i s p l a y C i r c u i t s . . . . . . . 1 1 c o n t i n u o u s r a t e d p o w e r o u t p u t

4、. . N o m o r e t h a n 0 . 0 0 5 %4.5 Protection Circuit 13 60 watts per channel power46 Surge current suppressor l5 ,1r,jlltr,r.ion oirioriion iuo rrrrrltrl;f ;:ltjT:fl1 E5 DISASSEMBLY 15 continuous rated power output . . No more than 0.005%6. PARTS LOCATION 16 60 watts per channel power7. DIAL CO

5、RD STRINGING . 18 output . . . No more than 0.005%g. ADJUSTMENTS Frequency Response8.1 Audio Section 1e rnpr.s.nriiiui,vli,.np.oun.t,i;ff T iorTln?,t.2 *! aa8.2 Tuner Section. 20 . . . . . l V/50 kilohms9, SCHEMATIC DIAGRAM 24 OUtPUt10. p.c. BoARDS coNNECTToN DTAGRAM 29 -speaker A B A+BDamping Facto

6、r (20 Hertz to 20,000 Hertz, 8 ohms)I 1 . P A R T S L I S T . 3 5 . . . 6 012. EXpLoDED vtEW 41 Hr.; rtr.ir. iiHi, rrrortcircuiteo, A network)1 3 . P A C K | N G . . . . 4 6 1 1 5 d 8ADDTTTONAL SERVTCE MANUAL FOR S/G TYPE 41 Preamplifier SectionI nput (Sensitivity/lmpedance)PHONO 1,2. . . 2.5mV/50 k

7、ilohmsAUX, TAPE PLAY 1, 2,A D A P T O R I N . . . . . . 1 5 0 m V / 5 0 k i l o h m sPhono Overload Level (T.H.D. 0.005%, 1,000 Hertz)P H O N O 1 . 2 . . . 3 0 0 m VOutPut ( Level/l mPedance)TAPE REC 1, 2. ADAPTOR OUT150mVPREAMP OUT (RL: 50 kilohms). . . . 1Vl1 kilohms (Volume: max.)Total Harmonic D

8、istortion (20 Hertz to 20.000 Hertz)PHONO 1.2 (REC OUT) . . . . . . No more than 0.005%(10V output)RadioFans.CN 收音机爱 好者资料库sx-3900AUX, TAPE PLAY 1, 2. ADAPTOR INNo more than 0.005%(10V output)Frequency ResponsePHONO (R IAA Equalization). . . 20 Hertz to 20,000 Hertz t0.2dBAUX, TAPE PLAY 1,2, ADAPTOR

9、OUTTon. contror 7 Hertz to 80 000 Hertz +9 dBBASS . !4dB/!7dB (100H2)f u rnover F requency : 2OOHz/ 400H2TREBLE +gdB/t7dB (10kHz)Tu rnover Frequencv : 2kHz I 4kzFilterLOW. . 15Hz (-6dB/oct.)HIGH . 8kHz (-6dB/oct.)Loudness Contour (Volume control set at -40dB position). . . . +6dB (100H2), +3dB (10 0

10、00H2)Hum and Noise (lH F, short-circuited, A network)P H O N O . . . . . . 8 6 d BAUX,TAPE PLAY 1,2,AM Tuner SectionSensitivity (lH F, Ferrite antenna) . .(lHF, Ext. antenna) .SelectivitySignal-to-Noise Ratiolmage Response RatiolF Response Ratio. .AntennaAudio SectionOutput ( Level/l mpedance)FM (10

11、0% Mod.).AM (30% Mod.) .Semiconductorsl C s . . .F E T s .Tra nsistorsDiodesM iscellaneousPower RequirementsPower ConsumptionDimensionsWeight (without package)Furnished PartsOperating instructionsFM T-type antenna300sV/m1 SpV30dB50d B40dB40dBFerrite loopsticka ntennaA D A P T O R I N . . .Attenuator

12、.FM Tuner SectionUsable Sensitivity (lH F )50dB Ouieting SensitivityMONOSTEREOSignal-to-Noise RatioMONOSTE R EODistortion (at 65dBf )MONO 100H2.lkHz .6kHz STEREO 100H2.ikHz .1 05dB-20d89.8dBf (1.7pV)14.2dBf (2.8pV)36dBf (34.7pV)83dB (at 65dBf)78dB (at 80dBf)0.1o/oo.o7%oJ%O.27oo.15%O.2To650mV/2.4 kil

13、ohms20OmV /2.4 kilohmst 5o8962AC 120V.60H2350W (UL)526(W) x 176(H) x452(D) mm20-11/16(wl x6-1 5/16(H) x 17-14/16(Dl in2Okg (441b 2ozl11* Measured pursuant to the Federal Trade Commissions TradeRegulation rule on Power Output Claims for Amplifiers.NOTE:Specifications and the design subject to possibl

14、e modificationswithout notice due to improvements.6kHzCapture Ratio. . 1.0d8Alternate Channel Selectivity4 0 0 k H z . . . . . . 8 0 d BStereo Separation1 k H z . . . . . . . 5 0 d 83 O H z t o 1 5 k l l z . . . . . . . 3 5 d BFrequency Response. . . . 2 O H z t o 1 5 k H z 1 ! j a aSpurious Respons

15、e Ratio . . . . . . . 100dBl m a g e R e s p o n s e R a t i o . . . 9 0 d Bl F R e s p o n s e R a t i o . . . . . . 1 0 0 d 8A M S u p p r e s s i o n R a t i o . . . 6 0 d BSubcarrierProduct Ratio . . . . . . . 64dBS C A R e j e c t i o n R a t i o . . . . 6 4 d BMuting Threshold 19.2dBf (SgV)Ant

16、enna Input . 300 ohms balanced,75 ohms unbalanced.2.FRONT PANEL FACILITIESO POWER SWITCHSetthisswitchtooNtosupp|ypowertothereceiver.There will be a short delay when it is set to ON becausethe muting circuit has been actuated to suppress theunpleasant noise that is sometimes generated when thePower i

17、s switched on and off BASS TURNOVER SWITCHUse this switch to change over the frequency in whichthe sound adlustment with the bass control is startingto take effect. Select 200H2 or 400H2 in accordancewiththecharacterlsticsofyourIisteningroomandofyour speakers, and with your general preference EASS A

18、ND TREBLE CONTROLSUse these controls to adiust the bass and the treblelf you set the tone switch to ON and turn the basscontroItotherightfromitscenterposition,youwi|beab|etoemphasizethesoundinafrequencyrangewhichis lower than that selected by the bass turnover switchConversely, turning this control

19、from the center positionto the left will attenuate the soundYou can use the treble control to adjust the sound in afrequency higher than that selected by the treble turn-over switch. TONE SWITCHSet this switch to ON when adjusting the bass and treblecontrols. When set to the OFF position the tone co

20、ntrolcircuitsaredisengagedandfrequencyresponseisf|at.Thisfunctionisconvenientforcheckingphonocartridgeand speaker tone quality and listening room acousticsO TREBLE TURNOVER SWITCHUse this switch to change over the frequency in whichthe sound adjustment with the treble control is startingto take effe

21、ct Select 2kz or 4kHz in accordancew i t h t h e c h a r a c t e r i s t i c s o f y o u r I i s t e n i n g r o o m a n d o fyour speakers, and with your general preference noRProR swlrcHSetthisswitchtooNwhenreproducingsoundfromanoptional component which is connected to the ADAP-TOR iacks. Always s

22、et it to the upper position if you arenot using a component with these terminals TAPE DUPLICATE SWITCHSet this switch to ON when you want to duplicate oredit a pre-recorded tape using two tape decks TAPE MONITOR SWITCHEmploy for tape playback or to monitor a recording inprogress.1: Playback or monit

23、oring of a tape deck con-nected to the TAPE 1 jacksSOURCE: Be sure to set to this position when notusing the tape deck for playback and moni-tori ng 2: Playback or monitoring of a tape deck con-nected to the TAPE 2 jacksNOTE:When listening to records or broadcasts be sure to set thisswitch to SOURCE

24、 Sound witt not be obtained from speakersif it is set to 1 or 2.) BALANCE CONTROLUse this control to balance the volume of the left andright channels. First, however, set the mode switch toMONO. lf the sound appears to be louder on the right, itmeans that the volume of the right channel is higher.Tu

25、rn the balance control to the left and adjust. Con-versely, if the sound appears to be louder on the left, itmeans that the volume of the left channel is higher.Therefore. turn the balance control to the right andad just. After adjusting, return the mode switch toSTEREO. MODE SWTTCHUse this switch f

26、or selecting mono or stereo perform-a nces .STEREO: Set to this position for normal operations.MONO: When set to this position, the left and rightchannel signals will be mixed and repro-duced monophonically from both speakersystems.o voLUME CONTROLUse this control to adjust the output level to thesp

27、eakers and headphones. Turn it clockwlse to increasethe output level. No sound will be heard if you set it to-. The scale is graduated in dB which indicate theattenuation when the maximum output level is 0dB.) MUTING SWITCHSet this switch to the *20d8 position to attenuate theaudio output indicated

28、by the volume control by 20dB.There is no need to adjust the volume control if you usethis switch when turning down the audio output tem-porarily and when changing over records or tapes.G) HEADPHONE JACKPlug the headphones into this jack when you want tolisten through your stereo headphones.Release

29、both speaker switches if you want to listen tothe sound through your headphones only.(E SPEAKER SWITCHESDepress the switch corresponding to the speakers con-nected to the SPEAKERS terminals (A or B) on the rearpanel.You can depress both of these buttons to listen to thesound from two pairs of speake

30、r systems at the sametime.six-39cl(f LOW FILTER SWITCH (15H2)Depress this switch in the event that turntable rumble,recording cutting noise or other low frequency noisebecomes objectionable. Attenuation in the frequencyband below 15Hz is 6dB/octave.G) HIGH FILTER SWITCH (8kHz)Depress this switch if

31、record scratch noise or other highfrequency noise becomes objectionable. Attenuation inthe frequency band above SkHz is 6dB/octave.) POWER METERThis meter allows you to read out the rated power levelon the fluorescent display tube when speakers with anominal impedance of 8 ohms are connected to thes

32、peaker terminals. DrAL POTNTERThis pointer indicates the broadcasting stations. rnn STEREo rNDrcAToRThis indicator lights up when receiving an FM stereoprogram if the FM muting off switch is released. oUARTZ LOCKED |ND|CATORThis indicator lights up after the optimum tuning pointhas been obtained and

33、 displays that the receiving state isstabilized by the built-in quartz lock circuit.D SIGNAL INDICATORThis indicator lights in sequence from left through rightduring the tuning of an AM or FM broadcast in accord-ance with the strength of the signals being received.The optimum tuning point is where t

34、he maximumnumber of indicators light. rururNG rNDrcAToRWhen tuning in an FM station, the optimum receptionpoint is indicated when the center indicator lights up.When the left indicator has come on, rotate the tuningknob slightly clockwise. When the right indicator comeson, rotate the knob slightly c

35、ounter-clockwise. FREOUENCY DISPLAYThis indicates the frequency which is tuned.With FM reception, the letters FM appear on the leftof the display and MHz on the right. With AM recep-tion, AM appears on the left and kHz on the right.These change when the function selector position ischa nged. TUNING

36、KNOBUse this knob to tune in to broadcasting stations.5 FM MUTING OFF SWITCHWhen this switch is released and an FM broadcast tunedin, the muting circuit is activated inside to suppress theannoying interstation noise between the broadcastingfrequencies for noise-free reception When the broadcast-ing

37、station is far away or when receiving a station in afringe area, set tne switch to the OFF position and thentune in. lf there is a broadcasting station with a strongsignal level on the air next to a station whose programyou want to receive, you may not be able to tune insatisfactorily because the so

38、und will be drowned outby the stronger signals In cases like this set the FMMUTING OFF switch to OFF (depressed position) andtune in. The muting circuit does not work when thetuner is receiving AM broadcasts lf tuning has beenperformed after the FM MUTING OFF switch has beendepressed and a station s

39、elected. the quartz lockedcircuit is set to the OF F mode and the LOCKEDindicator does not light. FM 25PS SWITCHDepress this switch when listening to a Dolby* FMbroadcast; otherwise keep this switch at the releasedposition.) BRIGHTNESS SELECTORUse this switch to select the brightness of the powermet

40、er and the frequencY disPlaYBRIGHT: When using the receiver in daylight or other FUNCTION SELECTORDeoress the function switch which corresponds to theprogram source. Turn the volume control down firstbefore selecting a different function switch while thesound from one program source is being reprodu

41、cedFM:AM:Depress this switch for FM broadcastsDeoress this switch for AM broadcastsAUX: Depress this switch when listening to anaudio component connected to the AUXiacks.PHONO 2: Depress this switch when playing a record onthe turntable connected to the PHONO 2jac k s.PHONO 1: Depress this switch wh

42、en playing a record onthe turntable connected to the PHONO 1i acks.NOTE:OnlY one function switch should be depressed at a ilme LOUDNESS SWlrcHWhen listening to a performance with the volumecontrol turned down, depress this switch and the bassand treble will be accentuatedWhen the volume is low, the

43、human ear f inds it harder tohear the bass and treble than when the volume is highThe loudness switch is thus designed to compensate forthis def iciency. By depressing this switch the bass andtreble come through much more strongly and the soundtakes on a puncn even when the volume control isturned d

44、own.bright locationsDIM: At night or in dark locations when the exist-ing brightness is too high*Theword,DolbyisatrademarkofDoIbyLaboratoriesInc.3. BLOCK DIAGRAMTuner Sectionsx-39clclOUARIZ LOCKEOAM TUNERA M OAudio SectionIAPE 1 _-. .:- ADAPrcRREC PLAY OUT INR CnANNE- . IHL SAME A5 IHF L CHANEL )FRE

45、A!ENCYa r l rUIERSECTIONFL TUSErc ( HAl2010 )5-POINT SIGNALINDICATOR ORIVErUNNG INDICATOR FREOUINCY OISPLAYFM MHz, O D D D, t_, t_t.t_t t_tA M K H TCoUNTER Oi - D5TIME DIVISION7- SE6MNT OECODRROMs1 s2 s3 s44. CIRCUIT DESCRIPTIONS4.1 FM TUNER SECTIONFront EndThe FM front end of SX-3900 includes a 4ga

46、nged tuning capacitor, a dual-gate MOS FET-EoTooA l-slage RF amplifier and a modifiedai; circuit llcal oscillator This oscillator is auoiiug controled oscillator employing a vari-cap(variable capacitance diode) When the.quartz-lock,yrt.t (refer to Quartz-lock system) is not inoperution, a constant v

47、oltage is applied to thediode.lF Amplifier and DetectorThese employ 3 ICs and 3 dual-element ceramicfilters. fne lC (HA1201) of the first 2 stage con-stitutes a single-stage differential amplifier current-ii-lti.rg limitet. The IC (PA300?-A)-in the thirdstage, an improvement on the former iF system

48、ICliigool ai, includes an iF iimiter amplifierquadrature detector, meter drive and other cir-cuits. Performance in terms of distortion S/Nratio, delay characteristics, and other parameters,ho*, a marked improvement in comparison tothe PA3001-A.Ouartz-Lock SYstemThe quartz-lock system featured in the

49、 SX-3900stereo receiver is a frequency serl/o control systememploying a crystal resonator Any displacementi.r itt-lntlrmediate frequency (IF) is detected as aDC voltage by the discriminator (equipped with acrystal resonator) resulting in the local oscillatorirqtr-ry being corrected and subsequentlyl

50、ocked. This extremely stable frequency servo con-trol system thus ensures that tuned frequenciesremain tuned securely for as long as requiredWhen the IF signal appears at pin no17 of theIF system IC (PA300?-A), it is amplified and ap-ptiei to a crystal detector (see Fig 4-1) which con-sists of diode