Ampex-400-tape-adj维修电路原理图.pdf

ff1EWflELLXANDlflADZW:nTMJRTLLI*flnr!RadioFans.CN 收音机爱 好者资料库AMPEXMODEL400MECHANICALADJUSTMENTMANUALTableofContentsPagesSECTIONIGENERAL1-2SECTIONIIOPERATIONALIRREGULARITIESANDTHEIRCORRECTION1-3SECTIONIIIADJUSTMENTSA.BRAKELEVERPIVOTS1B.BRAKERELEASEARMRESETSTOP1C.TRIPLEVERSTOP1D.FASTFORWARDANDREWINDHOLDBACK1E,BRAKES1F.MASTERSWITCHADJUSTMENT2G.PLAYENGAGEADJUSTMENT2H.TURNTABLEREVERSINGSWITCH2I.TURNTABLEMOTORCENTERINGJ.POWERBOOSTERSWITCHADJUSTMENTK.TAKEUPTENSIONARMTENSION3L.PLAY RESISTORSWITCH,RECORDINTERLOCKSWITCH ANDPLAYHOLDBACKADJUSTMENTM,PLAYTAKEUP ADJUSTMENTN.REELIDLERHEIGHT40,TURNTABLEHEIGHTP.REELSIZESWITCHADJUSTMENT4Q.CAPSTANIDLERHEIGHT5R.CAPSTANTAPEGUIDEHEIGHTSRadioFans.CN 收音机爱 好者资料库AMPEXMODEL400MAGNETICTAPERECORDERMECHANICALADJUSTMENTMANUALSECTIONI-GENERALEachModel400recorderhasbeenverycarefullyadjustedbeforeleavingthefactory.Undernormalconditions,theseadjustmentsarequitestableandshouldnotbealtered.However,ifthemachineshouldgetoutofadjustmentthroughunusuallyroughhandlingoraccident,it mayrequireattention.Acompletedescriptionofalladjustmentsis containedinthismanual.DESCRIPTIONOFOPERATIONTheModel400machineusesamechanicallinkagetocontrolitsvariousfunctions.Twomotorsareused,oneforthecapstan drive,theotherfortakeupandrewindoftapeontheturntables.Thelatteroneisengagedwiththeproperturntablebyamechanicallinkageanddrivesitthrougharubbertireonthemotorpulley.Propertapetensionismaintainedbyafrictionholdback deviceusingfeltpads.Brakingtoallowrapidstoppingoftapemotionisperformedbyanadditionalsetoffelt-linedmechanicalbrakes.Themodeselectorswitch,togetherwiththeFlaybutton,servetocontroltapemotioninthemachine.Theformerpositionsthemodechangecamintoeither Forward,Rewind,orOffpositions.Settingthiscaminto theForwardpositionperformsthe followingfunctionsdirectionsofmovementarethoseobservedwhenviewingbottomsideoftopplate.1.BellcrankFig.2-5isrotatedcounterclockwise,movingturntablemotorlinkFig.2_6toleftandtherebycausingmotorpulleytoengagetakeupturntable.Simultaneously,rotationofbellcrank.shaft positions turntablereversingswitchFig.2-3,connectingmotorwindingssothat rotationindesireddirectionisproduced.,2.CamfollowerFig.1-2is movedtoleft,causingcamfoll4owerleverFig.1-3torotateslightlyin aclockwisedirectionaboutitspivotFig.l-6A.This motionisimpartedtothebrakereleasearmthrougb itspivotFig.1-7Acausingthisparttomove totheright.Iftheakeuptensionarmisinoperating positioneitherbytapebeingpraperLthreadedorbybeingheldoverinsomeothermanneragainstspringtension,thetripleverFig.1-5willcatchthetriggeredofthebrakereleasearmFig.1-7andtherebycaepositiontobeimpartedthroughthebrakereleaserodstothel-lO.1-i5.Acol1araterswitchactuator,Fig.1-17ontebrakerodFig.1-11alsowilloperatethemasterswitchFig.1-19,energizingtheturntablemotor,FastForwardoperationwillthenoccur.Ifthe takeuptensionarmisnotinoperating position,thebrakereleasearmwillrotatecounterclockwiseaboutitspivot.Nomotionwillbeimpartedtothebrakerods,brakeswillnotrelease,andmasterswitchwillnotclose.Inaddition,themodeselectorwillnotlatchinanoperating positionIfthemodeselectorcam isplacedinRewindposition,themotionobe11crankandturntablereversingswitchwillbein aclockwisedirection.Themotorwillrotateinoppositedirectiontothatdescribedaboveandwillbeengaged totherewindturntable.TheactionofbrakelinkagewillbethesameasforForwardoperation.ShouldthePlaybuttonbedepressedpriortoplacingmodechangecaminForwardposition,anadditionalfunctionoccurs.TheplayengagedogFig.2-2willcatchtheendoftheplayengageleverFig.2-4causingtttorotatein acounterclockwisedirection.This motioninturnwillbeimpartedtotheplayengagetierodFig.2-22,movingittotheleft.Sinceitisattachedtothecapstan idleradjustmentarmFig.2-21,theidlerassemblywillrotatebringingthe id.leragainstthecapstan.Inaddition,apinaffixednearthecenteroftheplayengagetierodwilloperatetheplayholdbackactuatorFig.2-12,thusincreasingtheholdback effecttomaintainpropertapetension.Simultaneously,movementoftheplayhold-backactuatorpositionstherecordinterlockswitchFig.2-13,andtheplayresistorswitchFig.2-10.TheformerinterlockstheRecordbuttonontheelectronicsunit,whilethelatterreducesvoltageontheturntablemotorandconsequentlyreducesitstorquetotheamountneededforpropertapetensioninthePlaymode.Othercontrolsprovidedarethepowerswitch,whichturnsontheelectronicunitsandenergizesthecapstandrive motor,thereelsizeswitchthisunitisaswitchinnameonly;itservesasamechanicallinkagetocontrolpressureonplayholdback,andtape speed switchwhichcontrolspeedofthedrive motorbyvaryingconnectionofitswindings.SERVICING:beforeproceedingwithadjustments,thetapetransportmechanismandelectronicsshouldberemovedfromthecabinetandthetapetransportmechanismshouldbeplacedupsidedowninthecabinetwithitsfronttowardthefrontofthecabinet.Mostoftheadjustmentscanbemadewiththemachineinthisposition.Therecorderwasdesignedforuseeitherinthehorizontalpositionor forrackmounting.Theonlyadjustmentaffectedisthe takeuptensionaimtension.Seetakeuptensionarmtension adjustment.AMPEXMODEL400MECHANICALADJUSTMENTMANUALSECTIONIIOPERATIONALIRREGULARITIESANDTHEIRCORRECTIONSnappingthemodeselectorintoForwardpositionwithPlaybuttondepressedmaycausethemachinetotripoff.Ifthemachinetripsoffwithnormaloperationofthemodeselector,checkthefollowing:1.Playengageandmasterswitchadjustments.SeeSectionIII2.Take-uptensionarmtension.Itmaybetoohigh.3.Power bcxt switchadjustment.4.Possiblefailureofmasterswitchorturntablereversingswitch.WhenstartinginPlaymode,if excessiveslackdevelopsintapebetweencapstanandholdbackreeltherebycausingtapetotrackoutofthecapstanengagementandpossiblybreak,thecauseisinsufficientplayholdback.Checkthefollowing:1.Largereelonpayoutturntablewithreelsizeswitchinsmallreelposition.2.Playholdbackadjustment.Iftakeuptensionarmcontinuestooscillateaftermachineisstarte.inPlaymode,checkthefollowing:1.Fastforwardaridr.windholdbackadjustment.2.Takeuptensionrnfor excessivetension.Ifmachinefailstotripoffwhen taperunsout orbreaks,checkthefollowing:1.Takeuptensionarmtensionwillbetoolow.2TakeuptensionarmshaftmaybebindingduetogummyconditionIfso,remove,clean,andreplace.Lubricatewithafewdropsoflightoil.Iftapeconsistentlyscrapestheflangesofeither,reel,checktirifollowingtee1forbentflanges2.Differentrollsoftape.Sometapemayhaveinternalstrainsorbeimproperlyslit,causingittowindimproperly.3.Turntableheight.Iftapedoesnottrackproperlyinreelidlergroove,checkreelidlerheight.Tape shouldnotbearheavilyoneitheredgeofguidegroove.IfthemachinefailstogointoPlaymodewhenproperlyoperated,butgoesinsteadintoFastForward,thecauseisprobablya gummyconditionbetweenthePlayengagedogandthemodechangecam.Removethemodechangecamandwashthestickypartswithsolvent.Placeadroportwooflightoilonthedogpivotwhenreplacing.Ifmachinefailstooperatewhenmodeselectoristurnedtoanoperatingpositionandwhenmodeselectorreturnstooffwhenreleased,checkthefollowing:1.Triplever.If gummy,remove,clean,andreplace.Besurethatspringisattached.2.Triplevers.topadjustment.Ifmachinefailstooperatewhenmodeselectoristurnedtoanoperatingpositionandmodeseiectorremainsinthatposition,checkthefollowing:1.Masterswitchanditsadjustment.2,Turntablereversingswitchanditsadjustment.3.Topplatefuse.4.Powerswitchandtopplate wiring.Ifbrakingistoosevereorirregularthecauseisprobablyaforeigndepositonthebrakedrums.Cleandrumswithcarbontetrachlorid.orothersolvent.Thefeltliningsshould functionproperlyafterthedrumshave beencleaned.However,iftheyhaveinsomewaypickedupoiltheyshouldbe.replaced.Iftherubbertiredturntable drivewheelslipsonthebrakedruminanymode,thesituationshouldbecorrectdimmediatelyastl!rubbertirewillbeinjured,andrubberwillbedepositedonthbrakedi1rnscausingbrakeandholdbackproblems.Checkthefollowing;1,Presenceofoilonbrakedrumsor.tire.2.Turntablemotorcenteringifslippageoccursinonlyonedirection3.Masterswitchadjustment.Iftapetendstowanderupordownfromengementbetweencapstanandcapstanidler,checkthefollowing1.Capstanidlerheight.2.Capstantapeguideheight.3.Playholdbacktensioneithertoogreatortoolight.4.Playresistorswitchnotcuttingin.5.Powerboostswitchadjustment.Withthemachineinplaymodethereshouldbeanextrasurgeofpowerasthe takeuptensionarmisforciblymovedinagainstthetape.Ifthissurgedoesnotoccurbeforethemachineshutsoffduetothetakeuptensionarmbeingpushedtowardtherestoroffposition,thenthemachinecannotoperatesatisfactorily.Checktheplayresistorswitchand powerboostswitchforproperadjustmentandifnecessarymakefurtherchecktodeterminethattheswitchesarefunctioning.MODEL400MECHANICALADJUSTMENTMANUALSECTIONIIIA.BRAKELEVERPIVOTS-FIG,1-20Ifforanyreasonthebrakeleversareremoved,replaceinsame.positionfromwhichtheywereremoved.Tightenlocknut,Fig.1-20,untilit bottomsonthebrakelever,thenbackoffapproximately1/4turn.Allownodragonthebrakeleveratthis point.B.BRAKERELEASEARMRESETSTOP-FIG1-81.Placemodeselectorinoffposition.2.Loosensecuringscrew,Fig.1-8Aandsetstop sothatthetriggeringendof thebrakereleasearm9Fig.1-7,isapproximately1/16fromthebrakereleasearm triggerendstop,Fig.1-7B.3.Tightensecuringscrewusingcaretoavoidmovingstop asscrewistightened.C.TRIPLEVER STOP-FIG,1-41.Fastentakeuptensionarminoperatin,positionwithScotch tape.2.Loosenstopsecuringscrew,Fig.1-4A,andturnstoptoapositionthatwillallow3/64to1/16contactbetweenthetriggerendofthebrakereleaselever,Fig.1-7,andthetriplever,Fig.1-5,asthmodeselectoristurnedfromofftowardeitheroperatingposit.3.Tightenstopsecuring screw.D.FASTFORWARDANDREWIND HOLDBACK-FIG.2-8and241.Removebrakedrums.Notepositionsothateach drummasplacedontheshaftfromwhichitwasremoved.2.Therewindandfastforwardholdbackarms,Fig.2-8and24.have arestposition2-3/4inchesfromtheturntableshaft,Bend.a.apointclosetotheirmountingstocorrectanymisadjustinent.Besurethat linings contactdrumsevenlyanddonotbearheavilyorheelortoeoflining.E.BRAKES-FIG.1-10and151.Swingtakeuptensionarmontopplatetooperating positionandfastenittherewithScotch tape.2.Turnmodeselectortoeitheroperatingposition.3.Loosensetscrewonrewind brakeadjustmentcollar,Fig.1-9,adadjustbrakeshoetohaveminimumclearancefrom drum,Tightensetscrew.Checktodeterminebrakedoesnot,drag.4Loosensetscrewontakeupbrakeadjustu,ncllarandadjust.brakeshoetoclearbrakedrumby1/32TietacrewF.MASTERSWITCHADJUSTMENT-FIG.1-191.Fastentakeuptensionarminoperating positionwithScotchtape.2.WiththePlaybuttondepressed,movemodeselectorinforwarddirectionuntilmasterswitch timinblineoncamfollowerarm linesupwiththeedgeofthemodechangecamas showninFig.1-21.3.Setmasterswitchtoclickatthispointbyadjustingpositionofthemasterswitchactuator,Fig.1-17.Fineadjustmentsmaybemadebybending themasterswitchtongue,Fig.1-18,slightly.4.Tightensetscrewinthemasterswitchactuatorandrechecktoseethatthemasterswitchclicksjustastheedgeofthecamlinesupwiththemasterswitch timingline.Alwaysperformthischeckinplaymode,G,PLAYENGAGEADJUSTMENTAlwayscheckmasterswitchadjustmentseeprecedingparagraphbeforemakingthisadjustment.1.Fastentakeuptensionarminoperating positionwithScotchtape.2.Adjustcapstan idleradjustmentclamp screw,Fig.2-19,togivemediumdragbetweencapstan idleradjustmentarm,Fig.2-21,andcapstan idler armshaft,3,DepressPlaybuttonandmovemodeselectorinforwarddirectionuntilmasterswitchclicks.Shiftthecapstanidlerarm,Fig.2-20,withrespecttothecapstan idleradjustmentarm,Fig.2-21,sothatthecapstan idlerFig.2-17isabout1/64 fromthecapstan,Fig2-16,asthemasterswitchclicks.4.Securelytightencapstan idleradjustmentarmclamp screw,Fig.2-19.5.RecheckbydepressingPlaybuttonandmovingmodeselectorinforwarddirection.ThemasterswitchshouldclIckasthecapstanidlerreachesapointabout 1/64fromthecapstan.Donotallowthecapstan idlertotouchthecapstanbeforethemasterswitchclicksH.TURNTABLEREVERSINGSWITCH-FIG.2-31.Loosen clampboltonbellcrank,Fig,2-5A;2.WithmodeselectorinOffposition,rotateswitchswitchrotorbladesarecenteredintheswitch,3.Tightenbellcrankclampbolt.shiftuntiltheIfthemodeselectordoesnotsecurelylockinbothpositionswhenthe takeuptensionarmisheldinoperatingposition,itis probablybecauseofmisadjustmentofthisswitchThestopontheswitch iscausingaprematurestoppageofthecamReadjustslightlytocorrectthiscodi.tion.I.TURNTABLEMOTORCENTERING-FIG,2I.Removeturntablemotolink,Fig.26,mbellcrank.Fig.2-5.2.Holdthe.turntablemotorcenteredaccuratelybetweenthebrakedrums.Asimplecenteringjibcouldconsistoftwopiecesof1/16thickmetalinsertedbetweenbrake drumsandturntablemotortire.3Revolvetheturntable motor link,Fig2-6,untilitlinesupwiththeoutside holeinthebellcrank,Fig2-54.InsertturntablemotorlinkfromcastingsideandinstallnewretainingringJ.POWERBOOSTERSWITCHADJUSTMENT-IG.1-161.Movethetakeutensionarmfromitsrestoroffpositiontowardthereelidler,Thepowerboostmicroswitchshould clickoropenasthearmguidepassesthrougha linedrawnbetweenthecenterofthereelidlerandthecenterofthe takeuptensionarm bearing.2.Ifnecessary,adjustbybending themicroswitcharmslightly.K.TAKEUPTENSIONARMTENSION-FIG.1Theamountoftensiongiventothetakeuptensionarmisimportant.Anamountjustsufficienttotripthemechanismshouldbemaintained.Ifexcessiveitwillcausethemachinetoshutoffduringrewindorfastforwardandcausestartingdifficulties.Forrackmounting,additionaltensionhastobeprovidedtocompensatefortheweightofthetensionarmAdjustmentisaccomplishedbylooseningthelocknutatthecamfollowingarmpivot,Fig.1-6A,and movingtakeuptensionarmadjustmentlug,Fig.1-6,toobtaincorrecttension.Forrackmountingitmaybenecessarytoshortenspringtosecuresufficienttension.L,PLAYRESISTORSWITCH,RECORDINTERLOCKSWITCH ANDPLAYHOLDBACKADJUSTMENT1.Faste.ntakeuptensionarminoperating positionwithScotchtape.2.Connectohmmeteracrosstheoutsideterminalsofplayiesistr,Fig.2-15,usingalowresistancerange,todetermineexacttimeofplayresistorswitch action.3.Playholdbackactuator,Fig.2-12,shouldbeinapproximatelynormal positiononshaft.4,Loosenclampscrewonswitchactuator,Fig.2-25,butmaintainslightdrag.5Moveswitchactuator,Fig2-25,ontheswitchshaftothattheresistorcutsinafterthemasterswitchclickasthemodeselectoris movedintheforwarddirectionwiththeplaybuttondepressedResistorshouldcutinwhenpositionofthemodeche.ngecamandcamfollowerareas showninFig36WithmachineinPlaymode,readjustplayholdbackactuatorasshowninFig2-12untilitpressestheentire surfaceoftheplayhdbackfeltevenlyontheholdbackbrakdrumPlayhod,bakshouldbe4oz,measuredwithrecorderinPlaymodeandfromN. A. B.hub,Reel sizeswitchshouldbeinlargereelposition.Securelytightenclampscrewwhenadjustmentiscompleted.7.Recheckplayresistorandrecordswitch,BesuretheplayresistorswitchiscorrectlyadjustedasinParagraph5,above,Recordinterlockswitchadjustmentisalsoaccomplishedbythisprocedure.M.PLAYTAKEUPADJUSTMENTTheslideontheplayresistor,Fig.2-15,adjuststheplaytakeup.Movingtheslidetowardthetopplateincreasesthetakeup.Tocheckforpropertension:1.Fastentakeuptensionarminoperating positionwithScotchtapeand withtransportmechanisminnormal positionandpowerconnected.2.Attachashortpieceofstringabout30tothetakeupreelhubN.A.B.withtheotherendattachedtoaspringscaleOr16oz,preferred.3.PlacethemachineinPlaymode.4.Thetensionshouldbe8-1/2to9oz,asthescaleisallowedtomoveslowlyinthedirectionofpullofthereel.N.REELIDLERHEIGHTTheheightofthetapeabovethetopplate isdeterminedbythetapeguidesintheheadhousing.Itshouldbeapproximately3/4inches,measuringfromthebottomofthetapetothesurfaceofthetopplateSAdjustmentofreelidlerheightismadebyloosen