Ampex-400-tape-sm维修电路原理图.pdf

AMPEx SERIES4b0 OPERATIONAND MAINTENANCEMANUAL SERIES400 RadioFans.CN 收音机爱 好者资料库 MODELS402 64 minutesat7-TRinchspeedoneachtrack.ThestandardRMAreelmayalso beusedonthetapesupplyturntable.TheModels400Aand402MagneticTape Recordersaredesignedtorecordononly onehalfofthestandard1/4inch widetapeinaccordancewithRMAstandards.Byturningthereeloverandre cordingontheother half,twicetheamountofprogramcanbestoredonasingle reel,therebyaffectinga50%savingintape. REW1NDTIME.Approximatelyone andahalfminutesforthefull2,400foot NARTBreel. CONTROLS.FourbuttonscontrolthefunctionsofStartPlay,FastForward, ewi5dinZStop.Aseparaterecordbuttonenergizestherecordrelay,which dropsoutwhenthemachineisstopped.Sincethefunctionsare relayoperated, thecontrolbuttonsmaybeplacedataremotelocation. COMPLETELUG-INHEAD HOUSING.Erase,recordandplaybackheadsare containedin asingleplug-inheadhousing. SIMULTANEOUSMONITORING.Independentrecordandplaybacksystems allowthetapetobemonitoredwhilerecording. INUTJswitch allowstherecordertoaccommodateeithermicrophonelevel FoIiipedanceinputortobridge600ohmsplus4 VUline balancedorun balanced.Minus70dbmonmicrophoneinputwillproducerecommendedrecord level. PLAYBACKAMPLIFIER.Plus4 VUoutputinto600ohmsbalancedorun balanced.Willfeedhiglflmpedanceamplifierdirectlywithapproximatelyone volt. METERING.A 4inchVUmeterismountedonthefrontpanelandprovidesfor: A.Directmonitorofrecordinputsignalbeforeorduringrecording. B.Monitorofrecordedoutputsignalfromplaybackheadwhilere cordingorduringplayback. C.Readingbiascurrent. D.Readingerasecurrent. MODEL400A, 4OlA,402 1.Installaspacerpanelatthetopoftherackifdesired. 2.InstallbelowthispaneltheMechanicalAssemblyformachine#1. 3.InstalltheElectronicAssemblyformachine#1. 4.Installaspacerpanel. 5.InstalltheMechanicalPssemblyformachine#2. 6.InstalltheElectronicAssemblyformachine#2. 7.Installaspacerpanel. 8.InstallbothPowerSupplyPanelsatthebottom. Thecableonthepowersupplyfortheupperrecorderwillhave tobeextendedinlength.Extension cable#3814isavailable for thispurpose, Thenumberssetoffinparenthesesinthefollowingtextarereference numbersthatrefertothePartsListSectionIXandthefiguresintherearof thisbook. I. ConnectthePower Cable,catalog#2413,fomtheACPowerInputCon nectorJ4092ontheElectronicsAssemblytoasourceof115VoltPCpower. IMPORTPNT:Thtsmachineisavailable foreither50or60cycleoperation. Thepowerlinefrequencyisindicatedontheserialnumberplatewhichislo catedonthePowerSupplyPanel for rackmountedmachinesandontheexterior ofeachcaseintheportablemachine. Ii.OlTT:RefertoFigure1or2. A.ForStudioLine: Plus4VU,600ohmlineoutput,balancedorunbalanced,isavailable acrossTerminals 2and3oftheLineOutConnector,.7404,Pin 1isthe chassisground,ifunbalancedoutputisdesired;tieeithersideofthelineto ground.Itisnecessarytosupply600ohmterminationtothisoutputatall timesinordertomaintaincorrectmetercalibrationwhilerecordingorplay ingback.Therefore,iftheoutputisnotfeeding aterminatedlineoriftheout put is notconnected,suchasonremotepickups,theLineOutputTermination Switch,5404,mustheswitchedtoON. B.ForConnectiontoHighimpedanceAmplifierInput: Connectpin3oftheLineOutConnectorJ404,tothehighsideofthe amplifierinput.Strappins1and2oftheconnectorandconnecttotheground sideoftheamplifierinput.TheLine OutputTerminationSwitchS404,must beleftinthepositiondesignatedONatalltimes,asexplainedinAabove. SERIES400,SECTIONii,Page2 11/1/52 ill.iNPUT:RefertoFigures1or2and6. Thefollowing inputsareprovided: A.Microphones: Anylowimpedancemicrophone,thenominalimpedanceofwhichisinthe rangeof30to250ohmscanbepluggedindirectly.Connectthemicrophoneto pins2and3oftheInputConnector,3401S.Connectcableshieldtopin1. PlacetheInputTransferSwitch,S40l,intheMICposition. Themicrophoneinputtransformerisstrappedfortheoptimumstepupfor a150to 250ohmsource.Inthecaseofmicrophoneshaving50ohms orlessim pedance,6dbadditionalgaincanbeobtainedbystrappingtheinputas shownin Figure6B.Thisis notusuallynecessary,however,and shouldnotbedoneunless insufficientgainisfoundtoexist.Iftheinputisre-strapped,seriousfrequency discriminationwillexistshouldtheinputbefedfromasourceimpedancegreater than50ohms.IMPORTANT.R402andR403 willhavetobechangedto24ohms andP401andP404to68,000ohmstomaintainaflatresponseonBalanced Bridgingwhenthetransformerisstrappedfor50ohmsourceimpedance. Highimpedancemicrophonesarenotrecommendedforuseonthisequipment. Ingeneral,thequalityobtainablefromhighimpedancemicrophonesis notsat isfactoryforprofessionalwork.Intheeventthatitbecomesnecessarytoconnect ahighimpedance microphone,theinputcircuitwillhavetobere-wiredas shown inFigure6A. B,Bridging a BalancedStudioLine: Connectabalancedlinetopins2and3oftheInputConnector,J4O1S. Pin1isground.PlacetheInputTransferSwitch,S401,in theBALANCEDBRIDGE position.Inputlevelsofminus10toplus10VUcanbeaccommodated.Theload placedonthelineisapproximately300,000ohms. Forbridginghigherorlowerlevellines,anexternalbridgecanbewired intheline tothemachine.Thiswouldconsistoftworesistors,thevalueofwhich shouldbefrom15,000 to30,000timestheRMSprogramvoltage,inserieswith eachsideoftheline.A24ohm/5%resistorshouldterminateeachlegoftheout putsideofthetwobridgingresiiiors.Thejunctionofthetwo24ohmresistors shouldgotochassisground.Theoutputofthebridgemustbefedtothemicro phoneinputoftherecorder.Theinputoftherecordermaybeconnectedfor anyimpedancefrom50to250ohm. C.BridginganUnbalancedSource: Connectanunbalanced line,radio tuner,etc.,topins3and1oftheInput Connector340iS.Pin1isthegroundside.PlacetheInputTransferSwitch, 5401,intheUNBALANCEDBRiDGEposition.This connectionprovidesa 60,000ohmbridginginputforanyRMSprogramvoltagegreaterthan1/2 volt. SERIES400,SECTIONII,Page3 11/1/52 Toincreasetheinputimpedanceabove60,000ohms,aseriesresistance of 330,000ohmscanbewiredintotheinputpluginserieswithpin3and th-inputcable.Thiswillnecessitateaninputvoltageofatleast2-1/2 voiRMS.Itisimportantthatthisresistorbephysicallyplacedinthe cableconnectorthatplugsintotheRecorderInputJ4O1Sinorderthat thecablecapacitybeontheinputsideoftheresistor. IV,PHONES: AnysensitiveheadphonescanbepluggedinthePhoneJackJ403S, providedfor monitoringtheincominglineorplaybackoutput. V.REMOTE CONTROL:RefertoFigure7. ItispossibletoremotecontroltheStart,Stop,FastForward,Rewind, andRecordpushbuttonsofthisrecorder,Onstandardrecordersconnectthe remotecontrolsshowninFigure7AtotheRemoteControlTerminalStrip T5502showninFigure18.ineightwire cableisrequired. ifthistaperecorderisequippedforpluginofremotecontrols, connecta10pinmaleJonesplugJonesP-310-CCT-L,MPEXPL2O8Pto the8wire cableleadingtotheremotecontrols.Plugthecableintothe RemoteControlConnectorintherearoftherecorder.Ifremotecontrol shouldnotbedesired,Dummylug#3461mustbeinsertedinthisconnector. JonesP-3l0-CCT-Lwith7and8strapped. StandardrecorderscanbemodifiedforthepluginofRemoteControl and60CycleAmplifierconnectionsbytheadditionofan8anda10pinfemale Jonesconnector.Theseconnectorscanbemountedintheholesprovidedon theRelayMountingBracketIiintherearoftheMechanicalAssembly.The connectorsshouldbewiredtoTerminalStripsTSSO1andT5502asshownin FigureslBand7D. VI.60CYCLEMPL1FIER:ForDriveMotorPowerRefertoFigure7. ConnectionsforAM?EXModel375,60CycleAmplifier,orModel380 SpeedLockEquipmentaremadeonthe60CycleAmplifierTerminalStrip TSSO1showninFigure18,oratthe60CycleAmplifierConnector,ifthe recorderissoequipped.TheControlCircuitPowerFuseF402mustbein creasedto5ampereswheneitheroftheseunitsareused.RefertoFigure7D andtheModel375orModel380instructionBookforthedetailedinstallation procedure. NOTE:Ifthisrecorderisequippedforpluginof the60CycleAmplifier, UTsThecessarytoinsertDummyPlug#567inthe60CycleAmplifierre ceptaclewhenthe60CycleAmplifierisnotused. SERIES400,SECTIONii,age4 1i/i/sz Vu.CONVERSiONFRO T . B: V 12kICUNT: ifaportableorconsolec1erisconveice!oarackmountmachine, theTakeun Tensionrm:ounterbalancring6Srii:jt reaffded.Thisspring issuppliedwiththrecorderandishTrJetweenthlug providedonSafetywt li501ardthe. . :ctdecoitheTakeupTen sionrrnCollar .The 1eroTensiorcm.rxterbalancpring65is shoninstaLdcrackmounted-erationonH.tienshippedasa rackmountmachine,thespringw.iioeinstaile.ftceconversionistobeperm anerit,theoilingcupscitheTurritabietoter6, if.ipedithsI.evebearings, shoLidherotat3tcbea.ieforotii .ccsJNSrL.Nir: PNlNG:$efore 01en,.r;the:csoleorccitaecase:;, disconnectCoower. Completeaccessibilityforinspectionorserviceiiprovided totheto ndbottomoftheElectronicAssemblyandbottomoftheviechanicalAssemby. Figie21forillustrationofCabinetopenedforfullaccessibility. CoeningrocelLire 1.RemovethefourfrontparelscrewsX,Figure21,securing:lectronic Assemblytocabinet. 2.uIIElectronicsPsserrblyforwardinthepositionillustratedin Figure21. 3.Foraccesstoundersic ofrlectronicssencbly,pivctit backonthe hingeprotidedatrear. 4.Hingeatrearwill separatefor.torpieteremovalofchassisfromthe cabinet,ifdesired. 5.ToeMechanicalAssemblycanbFraisedtoa 450 positronremoving t.o!ont.1ccanical Asservst-czs,Y ,Figire21. 6.UsesiportredktosupportMechanical Assembly. 7.TheHechanicalssetblimayalsoberaised toaverticalposition andwiltbesupDuce:oyechainstop. IX.Cca:C1IlvDRiiDJCr*HANIC,LAS3K3L? s?TOCASLORT S;djechanicalAssembLyCaseonerdasshown in Figure22.Release latcheshal.Icenterdirisionsofcase.Inen Laaporoximately 900. Caremust betakert:jinsurethatcabJes*:anpassthroughcablecompar.ment intomain rabrcefteely. X.POChC;TOUND.RSIDECF i4CHNIC _ PSSEMBLYiNSINGLEC!SE PORTALE, SiLdetheElectronicsChassisoutof thecase. Removethehead cable SrIP1ES400,SECTIONII,Page 5 11/1/52 clampanddisconnect allcablesfromtheElectronicChassis.Removethe MechanicalAssemblybyliftingstraightup. Itmaybeturned upsidedown andplacedonthecase forservicing.Whenreturning theassembliestothe ca-se,makesurethecablesareproperlyclampedandthreadedthroughthe cableguidessotheywillnotinterferewithmovingparts. Xl,OVER/LLPERFORMANCECHECK:BeadSection111.onOEBfrTiON beforemakingthesechecks - Thefollowingprocedureis recommendedfor checkingthe performance ofthisrecorderatthetimeofinstallationandasnecessarythereafter. .OverallFrequencyResponse: Threadanewreeloftapeonthemachine.Equalizationcurves fortheRecordandPlaybackAmplifiersas showninFigure8and9have been establishedbyuseofMinnesotaMiningandManufacturingCompany Typelii Tape,ConstructionBREAorlater.Slight deviationsinperformancecanbe expectedwhenusingothertapes,butentirelysatisfactoryresultscanbeob tainedfromanyprofessionalqualitytane. 1.7-1/2InchResponseor3-3/4inchResnonseModels404trasethetapewiththeinput fThErdamplifiershorted.Rewindandplaythistapeback.Ptthe 7-1/2inchand15inch speedsthewidebandnoiseshouldbeatleast49db below onerat;.nglevelpoint ofapproximately1%totalharmonicdistortion. Ptthe3-3/4inchspeedforModels404and405,thenoiseshouldbeatleast 44dbbelowoperatinglevel.Noattemptshouldbemadetomeasurewideband SERiES400,OCTIONII,age6 11/1/52 noisevhdtstxz,ulLwus1yrecording and1ayingbackas - - ; ofYeflO1C iasirtoheplay-ackheadmayinterLwitht:C3S2c- C.Listortion; Dveralldistortioncanbetreasuredbyconnectinganystandard distcrtionrreasurenentappatatusacrosstheoutpuLThereadingsfromawave anayzerorselectivefrequencydistortionrreterwillbemore accuratethan thosefromanulltypeinstrumentatlowerdistortionlevels.Distortionread ingsaresome-,vhatdependentontape.readingoflisnormalatooerating levelwhi1areadingof3%isnormalat6dbaboveooeratinglevel. D.Flutter_andVow: Flutterandi1owarethechangeofsoeedoverashorttimeinterval inaDer1dicmanner.Theycanbemeasuredbymeansofasta3dardflutter bridgesuchas.F.TatumBeverlyHills,CaliforniaModel2-Flutter1eter. Variationsinamplitudeasindicatedonlevelmeasurementsdonotconstitute flutterandareentirelydue totaoecoatingvariations.Readingswillbewell 1nder.2%c.at15inch,.25at 7-1/2inchand.3at3-3/4inchspeed. Formoreinformationonalignmentorperformancechecking, referto STCTIONVI-cltgnment. SERII3400,SECT1ON11,7-age7 ii/i/sz SLCTIOIrIII OPLR4TINGIROCEDUR I,REELSIZE: Theturntableontheleftsidetapesupply isequippedtohandleeither theNP-RTBio-i/zreeloftape orthesmallerR.M.A.5and7sizes. On consoleorportablemachines positionthesmallreelsontheturntableengaging theturntable-keys.Forthelargeia-i/areel,usetheblackplasticCentering GuideCatalog#976thathasbeenprovided.Onrackmountmachines,usethe Hold-DownKnobCatalog#4402wthbothsmalland largereels. The#4402reelLold-downknobworksinthefollowingmanner.Are movablepininthebottomsurfaceoftheknobengagesacorrespondingholein theturntable.Acolietgripstheturntableshaftwhenthetopoftheknob isro tated.Twospringloadedballsholdthereeltotheturntable.Apininthe side oftheknobdrivesthereel.TheknobshouldbepositionedontheNPRTBreels sothattheremovablepinengagesoneoftheturntableholesandapproximately twothirdsoftheballisexposedabovethereel.Theknobshouldnotbepushed downalltheway,butshouldstickupabovetheturntable.Oncetheknobispo sitionedcorrectly,theNARTBreelsmayberemovedwithoutremovingtheknobs. WhenusingtheknobwiththesmallRMAreels,unscrewtheremovablepin.The knob isusedonlyt9preventthereelfromfallingofftheturntable,sincethree keysintheturntable driveandcenterthereel.Locktheknobtotheshaft,avoid: ingexcesspressureonthereelwhichcoulddistortthereelflanges. TheturntableontherightsideTakeupReelisdesignedtohandleonly theNtRTB10-1/2reel.Noattemptshouldbemadetousethesmallreelsizes onthisturntableastheperformanceoftherecorderwillbeseriouslyimpaired. U.TA?ETHREADING: Threadthetape asindicatedinFigure16.Allnewfactorywoundreels shouldbeunwoundandinspectedbyrunning throughatFastForwardbeforeusing theminthe?laymodeofoperation.Newtapesareusuallyloopedtothehubin such amannerthatthetapewillnotcomefreeofthereelattheendofthereel. ThiswillpreventtheSafetySwitch5501from disengagingtheCapstan Idler50 fromtheCapstanAwhichresultsinaflatbeingwornontheRubber:Capstan - IdlerWheel.Anyadhesivematerialaccumulationonthereelhubmustberemoved withsolventforthesamereason. Ill.HALF-TRACKOPERATION: Thehandlingofhalf-tracktapeonthis machineiaccomplishedinthe followingmanner.ThetapeisthreadedandoperatedasdescribedunderT Jii THRLADINGandTAF-MOTION.However,onlytheupperhalfofthetapewill beusedonthehalf-trackmachine.Toutilizethelower halfofthetape,thefull reelontheTakeupTurntableshouldberemoved,turnedoverandplacedonthe SERIF5400SECTIONIIIFage1 1i/i/sz TapeSupplyTurntableupsidedow.Placeanemptyreel ontheTakeupTurn table.Repeattheoperationasperformedonthefirst track. IV.POWER: PowerissuppliedthroughPowerSwitchS406,which mustbeturned ontooperatetheElectronicandMechanicalAssemblies.TheMechanical AssemblyandElectronicAssemblyareindividuallyfusedbythe2ampereCon trolCircuitFuseF402andthe 1ampereElectronicsFuseF401, V.SEEDSWITCHES: Therearetwoswitchesassociatedwithoperatingspeed.Speed Switch 5502governsthemotor,andtheEqualizationSpeedSwitch5402corrects theequalizationintheamplifiers. VI.TAPEMOTION: - Thetape motioniscontrolledbymeansoffourpushbuttonslabeled Stop,Start,FastForward,andRewind. 1.PlayorRecord:ThetapeissetintoPlaymotionatthespeedselected -bytheSpeedSwitchwhentheStartButton5507isdepressed.The tapemustbecompletelystoppedbeforestartinginthismode.To changefromPlaymodetotheRecordmode withthetapeinmotion, presstheRecordButton5403. 2.Stop:Tostopthetapemotionvhileitismovinginany modepress