Hitachi-SR2004-rec-sm维修电路原理图.pdf

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1、., SERVICEMANUAL English Franc;ais No. 128 SPECIFICATIONS FMSECTION 85 dB 45 dB I dB 60dB 50dB(IkHz) 70dB 70dB 28dBf(14pV) 300ohmsbalanced, 75 ohms unbalanced Frequency range Usable sensitivity 50dB Quieting sensitivity Signal-to-noiseratio(at 6S dBf) Harmonicdistortion(at6S dBf) NARROW100Hz I kHz 6

2、kHz WIDE100Hz I kHz 6 kHz Frequency response Image responseratio Spurious responseratio IF responseratio Alternate channel selectivity NARROW WIDE Capture ratio AMsuppression Stereoseparation Subcarrier suppression SeArejection Muting threshold Antennainput 88- 108 MHz Mono: 8.7dBf(1.5pV) Mono: 12.5

3、 dBf (2.3pV) Mono:75dB Mono: 0.15% Mono: 0.1% Mono: 0.25% Mono: 0.15% Mono: 0.07% Mono: 0.2% 30Hz-ISkHzC:aG) 115dB 120dB I5dB Stereo: 24dBf(8.9pV)Inside the parenthesisIHF58 Stereo:36dBf(34.5pV) Stereo:70dB Stereo:0.25% Stereo: 0.2% Stereo: 0.3% Stereo:0.25% Stereo: 0.1% Stereo: 0.3% -.STEREORECEIVE

4、R November 1977 RadioFans.CN 收音机爱 好者资料库 HITACHISR-2004 AMSECTION Frequencyrange Sensitivity Image rejection IF rejection Selectivity (IHF) Signal-to-noise rario Antenna AUDIOSECTION OutputRMSpower (Bothchannels driven) Music power (IHF) Powerbandwidth Frequencycharacteristics Harmonic distortion (at

5、ratedoutput) (at!zratedoutput) Intermodulationdistortion (atratedoutput) (at!zratedoutput) Inputsensitivity (at200Woutput,I kHz) PHONOI,PHONO 2 AUX TAPE-I TAPE-2 ADAPTOR DIN MIC Max.inputlevel (PHONO) Outputlevel TAPE OUT DIN OUT Signal-to-noise ratio (IHF,inputshorted, A-network, rated power) PHONO

6、1,2 AUX TAPE1,2 Damping factor Equalizer Basscontrol Midrangecontrol Treblecontrol 530- 1,605 kHz 370llY/m(S/N20dB), 20llY (IHF,ext.Antenna) 70dB 90dB 40dB 50dB Ferrite and Separate terminal 200watts per channel, min. RMS, at 8ohms from 20 Hz to20kHz, with no morethan 0.08%total harmonic distortion.

7、 230W/ch+230W/ch (8 ohms, I kHz, T.H.D. 0.08%) 230W/ch+230W/ch(4ohms,1 kHz, T.H.D. 0.1%) 400W/ch+400W/ch (8ohms) 10 Hz -40kHz PHONO30 Hz -15kHz 0.2 dB AUX10Hz -40kHz 1.5 dB Less than 0.08% Less than 0.03% 0.08% 0.03% 2.5 mY (47 k ohms) 150 mY(50k ohms) 150 mY (35 k ohms) 150 mY (35 k ohms) 150 mY (3

8、5 k ohms) 450mY(95kohms) 3 mY (50 k ohms) 500mY 150 mY (PHONO, AUXatratedinput) 200 mY (FM400Hz, 30% dev.input:1 mY) 150 mY (AM400Hz, 30%mod.input:5mY/m) 40mY (PHONOatratedinput) 75 dB 90dB 90dB 75(lkHz,8ohms) RIAA 0.2 dB 10dB(at50Hz turnover frequency 150 Hz) 10 dB (at 100 Hz turnover frequency300H

9、z) 6 dB (at 1 kHz) flOdB (at 10 kHzturnoverfrequency 3 kHz) I0dB(at 20 kHzturnoverfrequency 6 kHz) -2- e e RadioFans.CN 收音机爱 好者资料库 e Loudnesscontrol (Volumecontrolset at-33dB position) High filter Low filter Audiomutingeffect Tapemonitor Speaker switch Tuningmeter Powermeter ACoutlet Speaker termina

10、l FMMUTING/AUTO LOCK MPX noise filter IFBAND filter MULTIPATHfilter Pre/main amplifiers Adaptorswitch Power supply Powerconsumption Dimensions Weight +9 dB(100Hz),+4dB(10kHz) -10dBat10 kHz (12 dB/oct.) -10dBat50Hz (12 dB/oct.) -20dB, 0 dB,-40dB 1,2 A,B,C,A+B,B+C,C+A,OFF 2 2 3(Oneswitched50W a shut-d

11、own circuit and current limiter circuit.Ifthe shut-down circuitisactuated, theoutputofthe amplifieriscut off. When only the current limiter circuitisactuated, the operationofthe power amplifierisnotshut down. (4) Before takingoffthe couplers from the PRE OUT and MAIN IN terminals on the rear panel,

12、make sure that POWER switchissettoOFF andthatthe attenuator volumeissettothe lower position(00). (5) Set theMICMIXING volume controltoOFF when you are not using the microphone. total et un circuit de limitationdecourant. DansIe cas oilIecircuit de coupure totale est active, la sor- tiedeIamplificate

13、ur est coupee. Quand seulIecircuitdelimitation de courant est active, lamplificateur continueafonctionner. (4) Avantderetirer les barres daccouplement des bor- nes PRE OUT etMAININdu panneau arriere, prendre bien soindeverifier queIecommutateur dalimentation est bienmissur1aposition OFF (arret)etque

14、IevolumedeIattenuateur est sur la position la plus basse(00). (5) Mettrelacommandedevolumedemelange micro (MICMIXING) surlaposition OFFsivous nutilisez ,pasIemicrophone. - AVERTISSEMENT IMPORTANT- (1) Quand on mesurelapuissance en sortie ou que Ion ecoute des sources de programmes avec Iimpe- danced

15、echarge de 4-ohms,nepas faire fonctionner Iemodele SR-2004apleine puissance pendant une longue periode de temps. (2) Quandonutilise cet appareil avec un debit continuel de puissance depassant 200 watts,Ievoyant de pro- tection peut sallumer etIeson peut quelquefois sinterrompre. Ceci ne veut pas dir

16、e quil y ait une panne. Dans de tels cas, couper lalimentation, bais- serIeniveau du son, et puis attendre environ 30 secondes avant de reaIimenter Iappareil. (3)Lemodele SR-2004 est equipededeux types de cir- cuits de protection electronique; un circuit darret -5- HITACHISR-2004 -.- FEATURES TunerS

17、ection- 1.Dual Gate MOS FET for High QualityFMTuner Three Dual Gate MOSFETsinthefront-endand5-gang variablecapacitorsofferexcellentFMsensitivity (I.5j1V), intermodulation characteristics, high S!N ratio andspurious rejection. 2.Auto-LockCircuit Tostabilize tuning, anAuto-Lockcircuitisprovided. This

18、circuit engages immediately whenyourelease the tuningknobafter precise tuning.Justbytouching the tuningknob,you can disengagetheAuto-Lock circuit for(theAuto-Lock indicator goesoff)fine tuning. Releasingthetuning knob re-engagestheAutoLock circuit which automatically stabilizes the tuning circuit an

19、dlocksontothe station selected for a high S!N ratio andlow distortion. 3.IFBAND Selector Switch for Flexible Selectivity and SAWFILTER for Low Distortion IFBAND selector switchisprovided in theFMIF stage toprovide a selectivitythatmeets different receiving conditions. In the WIDE position,theSAWFILT

20、ER,which has superior group delay characteristics in the wide fre- quencyrange, andthe4-poleLCLINEAR PHASE FILTERoffer sound withextralow distortion. IntheNARROWposition,the2 LINEAR PHASE CERAMICFILTERwill alsooperatetocutoutthe interference sharply by high selectivity. 4.High-Selectivity and Low-Di

21、stortion IF Amplifier using ICsand3 Ceramic Filters A 6-stage differential amplifierisemployed.The exten- sive useof3Ies,andtwoceramic filter elements in the IF stage,thathave good phase characteristics, in theFM- IF amplifier greatly improvesthelimiter and selectivity characteristics. 5.QuadratureD

22、etection Quadrature detectionwiththeextensive useofIeshas a widebandcoverage and lowdistortion. 6.Phase-Locked LoopICforFM/MPX Circuit A PLL-IC, which was developedbyHitachi,isused for theFM!MPX circuit for a high separationandlow dis- tortion.Also, high reliabilityisachieved with respect to tempera

23、tureand aging. 7.Reed Relays for CuttingoutDetuning Noise In theFMMUTE position,twoReed Relays are pro- vided inFMaudiooutputstagetocutoutdetuning noise. 8.MPX NOISE FILTER Sometimeshighfrequency noisepreventsyoufrom obtaininghi-fidelityFMstereo reception. With some receivers,youhavetolistentobroadc

24、astsinmonoto reduce this noise. TheMPX NOISEFILTERcan be usedtoreduce this noisewithoutimparingtheFMstereo effect. 9.FMMULTIPATH Switch with MeterforBestFM Reception Direct signals and signals reflected by mountains and buildings cause a multipath effect. This increases dis- tortionand downgrades se

25、paration. Toeliminate this trouble, thereisamultipathdetection circuit which operates together withthesignal meter. 10.3-gang Variable Capacitor for High SelectivityAM Reception A 3-gang variable capacitorisprovided for achieving high sensitivity and selectivity duringAMreception. 11. Ceramic Filter

26、,ICsinAMTuner A ceramic filterisemployed intheAMtunertoobtain enhancedselectivity and AGC characteristics. The exten- sive useofIesimproves stable reception. 12.TwoLarge Easy-to-Read Metersanda Large-sized Fly- wheel Tuning Knob Twoeasy-to-read meters are usedtoindicate the signal andtuninglevels. T

27、he dial mechanism employs a large-sized fly-wheel with a highmomentofinertia for easy operation. AudioSection- 1. Newly Developed High-Efficiency High-PowerAudio Amplifier (Series E . Class GorDynaharmony Amplifier) This amplifier delivers a higherdynamicoUlpuCpower (400W per channel, 8 ohms)without

28、distortion than conventional class-B amplifiers. Therelative low powerconsumptionofclass G opera- tion minimizes thehealsinkofthepower transistors and the weightandsizeofthe whole amplifier. This amplifier has twinDCpower supplies. Under thismethod,c1ass-Goperationcan deliver dy- namic power whichis

29、morethantwice the valueofthe maximumratedoutputpowerormore. 2. Twin Power Meters(Land R channels) Toseetheactual poweroutputwhileyouare listening, combinedtwo new attractivepowermeters are provided. 3.MidrangeToneControl This amplifier hasnotonly BASSandTREBLE tone controlsbutalso a MIDRANGEtonecont

30、rol. Bysetting these three controls,youcan choosethepre- ferred frequency characteristicsoftheamplifier. Thecontrols all have11click-stopcontactpoints. This feature offers good feel which makes for easier set- tingandresetting. 4.Turnoverand Tone Defeat Switches This model hastwoturnover switches fo

31、r adjusting the lowandhigh frequency characteristics independently. Each switch has two turnover frequency settings. Inordertomake flat frequency characteristicswithout touchingtonecontrolstonedefeat functions are also provided. You can adjust the frequency characteristics tomeetthe acoustic conditi

32、onsofyoulistening room andtosuityourtaste. 5.CalibratedAttenuator(Volume Control) A precisely calibrated 32- click-stopcontactpointatten- uatorisused for the volumecontrol.This makes for easier setting and resettingofthedesired poweroutput level. 6.AudioMuting Switch This switchisvery useful when lo

33、weringthesound level withouttouching the levelattenuator.You can choose betweentwoattenuation values(-20dB,-40dB). Further,a more precise and flexible settingandresetting ofoutputlevel can be achievedbycombining the level attenuatorand the muting switch. 7. Mic Mixing A mic mixing circuitisincorpora

34、tedin this model. Justconnecta microphone andyouwill be abletomix soundsfromthemicrophonewithotherprogram sources. e e -6- - - 8. Tape Dubbing Tape dubbing can be done either from TAPE-ItoTAPE- 2 or vice versa. Thereisalso a sourcemonitorcircuit, with which tape dubbingispossible whi!e listeningtoan

35、 FMbroadcast or a record. 9. Low Filter and High Filter The low filter cutsoutthe low frequency noise suchas rumble from a turntable and the high filter cuts out the high frequency noise suchasnoise from scratcheson records and high frequency noise while listeningtoFM broadcasts. CARACTERISTIQUES Se

36、ction Tuner- 1.MOSFETadouble porte pour un TunerFMde haute qualite Les troisMaSFETa double porte montes dans letage dattaqueet les 5 groupes de condensateurs variables permettentdobtenirune sensibiliteFMexcellente (1,5 IlV), des caracteristiques dintermodulation,unrapport signal/bruit tres eleve et

37、une suppression des parasites. 2. Circuit auto-verrouillable Pour stabiliser la syntonisation,uncircuit auto-verroui!- lable est installe. Ce circuit senc1enche immediatement des que vous reliichezIeboutonde syntonisation apres avoirobtenuun accord parfait. Cest justeentouchantIe boutonde syntonisat

38、ion que vous desactivezIecircuit auto-verrouillable (Ie voyant du circuit seteint), pouvant proceder ainsi a une syntonisation precise. Quand vous lachez a nouveauIeboutonde syntonisation,Iecircuit auto-verrouillablesereenc1encheraautomatiquement stabilisant ainsiIecircuit de syntonisationetIebloqua

39、nt sur la station emettrice desiree, ce quipermettradobte- nir un rapport signal/bruit tres eleve et une faible distor- sion. 3. Selecteur de bandeFI(IF BAND) pour une grande flexibilite de choixetun filtreSAWpour une faible distorsion Uncommutateurselecteur de bandeFI(IFBAND) est installe dans leta

40、geFIFMpour vous permettre davoir une selectivitequisadapte a nimporte quelle condition de reception. Sur la position WIDE (large),IefiltreSAW qui possede des caracteristiques elevees de retard de groupe dansIedomaine des frequences longues,etIefiltre de phase lineaireLCa 4 poles permettentdobtenirde

41、s sons pratiquement denues de distorsion. Sur la position NARROW(etroite),les deux filtres ceramiques de phase lineaire seront actives aussi pour supprimerpratiquement toutes les interferences du fait de leur haute selectivite. 4. Amplificateur dehauteselectiviteetabasse distorsion utilisant des 3 c

42、ircuits integreset2 filtresaceramique On utilise un amplificateur differentiel a 6 etages. Lutili- sation continuelle de 3 circuits integresetde 2 elements de filtre ceramique dans letage FI, qui possectent dex- cellentes caracteristiques de phase, de lamplificateurFI FM, ameliore grandement les car

43、acteristiques de selecti viteetde limitation. 5.Detection quadriphonique La detection quadriphonique, a laide denombreuxcir- cuits integres, permet dobtenir une bande passante tres largeetune distorsion faible. HITACHISR-2004 10. Three Speaker Systems Connection Three speaker systems can be connecte

44、dtothe unit and selected with switches. 11. Electronic Protection Circuit Hitachis original, highly reliable electronicprotection circuitisbuilt-intoprotect the speakers and power transistors. When a fault occurs, the circuitisswitched offand thisisthendisplayed on the front panel by the light emitt

45、ing diode. 12. Adaptor Switch This functionisvery convenient for using a third tape deck or for a DolbyNRadaptor. 6.Circuit FM!MPXaboucle de blocage de phase equipee de circuits integres Un circuit integre PLL, developpe par Hitachi, est utilise pourIecircuit FM/MPX, permettant ainsidobtenirun haut

46、degre de separation et une faible distorsion. On a egalement une tres haute fiabilite quandonprenden consideration la temperatureetla duree de service. 7.Relaisalamepoursupprimer les bruits desaccordants Dans la positionFMMUTE,ona installe deux relais a lame dans Ietage de sortieFMqui suppriment les

47、 bruits desaccordants. 8. Filtre de bruitMPX(MPX NOISE FILTER) Quelquefois, des parasites de haute frequence vous em- ptkhentdobtenirune receptionFMde haute-fideliteet stereophonique. Avec quelques recepteurs,ilvous faut ecouter ces emissions au mode Mono afindereduireIe niveaudesparasites.Lemtre de

48、 bruit MPX (MPX NOISEFILTER)peutetre utilise pour reduirecegenre parasites sans nuire a leffetFMstereo. 9.CommutateurFMde trajets multiples (FM MULTI- PATH) avec indicateur pour obtenir une receptionFM encore meilleure Laddition des signaux directs et de ceux qui viennent, refletes par des montagnes

49、 ou des batiments par exem- pie, jusqua votre appareil produitcequonappelle leffet a trajets multiples. Cet effet diminue la separation et augmenteIeniveau de distorsion. Pour supprimer ce probleme,ily auncircuit de detection de leffet de trajets multiplesquiest active en meme temps que lindi- cateur de signaux. 10. Condensateur variablea3 groupes pour une selectivite elevee en receptionAM Un condensateur variable a 3 groupes est installe, ce qui permet davoir un niveau de sensibilite et de selectivite tres elevependantla r