Ampex-400-tape-adj维修电路原理图.pdf

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1、ff1EWflELLXANDlflADZW:nTMJRTLLI*flnr!RadioFans.CN 收音机爱 好者资料库AMPEXMODEL400MECHANICALADJUSTMENTMANUALTableofContentsPagesSECTIONIGENERAL1-2SECTIONIIOPERATIONALIRREGULARITIESANDTHEIRCORRECTION1-3SECTIONIIIADJUSTMENTSA.BRAKELEVERPIVOTS1B.BRAKERELEASEARMRESETSTOP1C.TRIPLEVERSTOP1D.FASTFORWARDANDREWINDHOL

2、DBACK1E,BRAKES1F.MASTERSWITCHADJUSTMENT2G.PLAYENGAGEADJUSTMENT2H.TURNTABLEREVERSINGSWITCH2I.TURNTABLEMOTORCENTERINGJ.POWERBOOSTERSWITCHADJUSTMENTK.TAKEUPTENSIONARMTENSION3L.PLAY RESISTORSWITCH,RECORDINTERLOCKSWITCH ANDPLAYHOLDBACKADJUSTMENTM,PLAYTAKEUP ADJUSTMENTN.REELIDLERHEIGHT40,TURNTABLEHEIGHTP.

3、REELSIZESWITCHADJUSTMENT4Q.CAPSTANIDLERHEIGHT5R.CAPSTANTAPEGUIDEHEIGHTSRadioFans.CN 收音机爱 好者资料库AMPEXMODEL400MAGNETICTAPERECORDERMECHANICALADJUSTMENTMANUALSECTIONI-GENERALEachModel400recorderhasbeenverycarefullyadjustedbeforeleavingthefactory.Undernormalconditions,theseadjustmentsarequitestableandshou

4、ldnotbealtered.However,ifthemachineshouldgetoutofadjustmentthroughunusuallyroughhandlingoraccident,it mayrequireattention.Acompletedescriptionofalladjustmentsis containedinthismanual.DESCRIPTIONOFOPERATIONTheModel400machineusesamechanicallinkagetocontrolitsvariousfunctions.Twomotorsareused,oneforthe

5、capstan drive,theotherfortakeupandrewindoftapeontheturntables.Thelatteroneisengagedwiththeproperturntablebyamechanicallinkageanddrivesitthrougharubbertireonthemotorpulley.Propertapetensionismaintainedbyafrictionholdback deviceusingfeltpads.Brakingtoallowrapidstoppingoftapemotionisperformedbyanadditi

6、onalsetoffelt-linedmechanicalbrakes.Themodeselectorswitch,togetherwiththeFlaybutton,servetocontroltapemotioninthemachine.Theformerpositionsthemodechangecamintoeither Forward,Rewind,orOffpositions.Settingthiscaminto theForwardpositionperformsthe followingfunctionsdirectionsofmovementarethoseobservedw

7、henviewingbottomsideoftopplate.1.BellcrankFig.2-5isrotatedcounterclockwise,movingturntablemotorlinkFig.2_6toleftandtherebycausingmotorpulleytoengagetakeupturntable.Simultaneously,rotationofbellcrank.shaft positions turntablereversingswitchFig.2-3,connectingmotorwindingssothat rotationindesireddirect

8、ionisproduced.,2.CamfollowerFig.1-2is movedtoleft,causingcamfoll4owerleverFig.1-3torotateslightlyin aclockwisedirectionaboutitspivotFig.l-6A.This motionisimpartedtothebrakereleasearmthrougb itspivotFig.1-7Acausingthisparttomove totheright.Iftheakeuptensionarmisinoperating positioneitherbytapebeingpr

9、aperLthreadedorbybeingheldoverinsomeothermanneragainstspringtension,thetripleverFig.1-5willcatchthetriggeredofthebrakereleasearmFig.1-7andtherebycaepositiontobeimpartedthroughthebrakereleaserodstothel-lO.1-i5.Acol1araterswitchactuator,Fig.1-17ontebrakerodFig.1-11alsowilloperatethemasterswitchFig.1-1

10、9,energizingtheturntablemotor,FastForwardoperationwillthenoccur.Ifthe takeuptensionarmisnotinoperating position,thebrakereleasearmwillrotatecounterclockwiseaboutitspivot.Nomotionwillbeimpartedtothebrakerods,brakeswillnotrelease,andmasterswitchwillnotclose.Inaddition,themodeselectorwillnotlatchinanop

11、erating positionIfthemodeselectorcam isplacedinRewindposition,themotionobe11crankandturntablereversingswitchwillbein aclockwisedirection.Themotorwillrotateinoppositedirectiontothatdescribedaboveandwillbeengaged totherewindturntable.TheactionofbrakelinkagewillbethesameasforForwardoperation.ShouldtheP

12、laybuttonbedepressedpriortoplacingmodechangecaminForwardposition,anadditionalfunctionoccurs.TheplayengagedogFig.2-2willcatchtheendoftheplayengageleverFig.2-4causingtttorotatein acounterclockwisedirection.This motioninturnwillbeimpartedtotheplayengagetierodFig.2-22,movingittotheleft.Sinceitisattached

13、tothecapstan idleradjustmentarmFig.2-21,theidlerassemblywillrotatebringingthe id.leragainstthecapstan.Inaddition,apinaffixednearthecenteroftheplayengagetierodwilloperatetheplayholdbackactuatorFig.2-12,thusincreasingtheholdback effecttomaintainpropertapetension.Simultaneously,movementoftheplayhold-ba

14、ckactuatorpositionstherecordinterlockswitchFig.2-13,andtheplayresistorswitchFig.2-10.TheformerinterlockstheRecordbuttonontheelectronicsunit,whilethelatterreducesvoltageontheturntablemotorandconsequentlyreducesitstorquetotheamountneededforpropertapetensioninthePlaymode.Othercontrolsprovidedarethepowe

15、rswitch,whichturnsontheelectronicunitsandenergizesthecapstandrive motor,thereelsizeswitchthisunitisaswitchinnameonly;itservesasamechanicallinkagetocontrolpressureonplayholdback,andtape speed switchwhichcontrolspeedofthedrive motorbyvaryingconnectionofitswindings.SERVICING:beforeproceedingwithadjustm

16、ents,thetapetransportmechanismandelectronicsshouldberemovedfromthecabinetandthetapetransportmechanismshouldbeplacedupsidedowninthecabinetwithitsfronttowardthefrontofthecabinet.Mostoftheadjustmentscanbemadewiththemachineinthisposition.Therecorderwasdesignedforuseeitherinthehorizontalpositionor forrac

17、kmounting.Theonlyadjustmentaffectedisthe takeuptensionaimtension.Seetakeuptensionarmtension adjustment.AMPEXMODEL400MECHANICALADJUSTMENTMANUALSECTIONIIOPERATIONALIRREGULARITIESANDTHEIRCORRECTIONSnappingthemodeselectorintoForwardpositionwithPlaybuttondepressedmaycausethemachinetotripoff.Ifthemachinet

18、ripsoffwithnormaloperationofthemodeselector,checkthefollowing:1.Playengageandmasterswitchadjustments.SeeSectionIII2.Take-uptensionarmtension.Itmaybetoohigh.3.Power bcxt switchadjustment.4.Possiblefailureofmasterswitchorturntablereversingswitch.WhenstartinginPlaymode,if excessiveslackdevelopsintapebe

19、tweencapstanandholdbackreeltherebycausingtapetotrackoutofthecapstanengagementandpossiblybreak,thecauseisinsufficientplayholdback.Checkthefollowing:1.Largereelonpayoutturntablewithreelsizeswitchinsmallreelposition.2.Playholdbackadjustment.Iftakeuptensionarmcontinuestooscillateaftermachineisstarte.inP

20、laymode,checkthefollowing:1.Fastforwardaridr.windholdbackadjustment.2.Takeuptensionrnfor excessivetension.Ifmachinefailstotripoffwhen taperunsout orbreaks,checkthefollowing:1.Takeuptensionarmtensionwillbetoolow.2TakeuptensionarmshaftmaybebindingduetogummyconditionIfso,remove,clean,andreplace.Lubrica

21、tewithafewdropsoflightoil.Iftapeconsistentlyscrapestheflangesofeither,reel,checktirifollowingtee1forbentflanges2.Differentrollsoftape.Sometapemayhaveinternalstrainsorbeimproperlyslit,causingittowindimproperly.3.Turntableheight.Iftapedoesnottrackproperlyinreelidlergroove,checkreelidlerheight.Tape sho

22、uldnotbearheavilyoneitheredgeofguidegroove.IfthemachinefailstogointoPlaymodewhenproperlyoperated,butgoesinsteadintoFastForward,thecauseisprobablya gummyconditionbetweenthePlayengagedogandthemodechangecam.Removethemodechangecamandwashthestickypartswithsolvent.Placeadroportwooflightoilonthedogpivotwhe

23、nreplacing.Ifmachinefailstooperatewhenmodeselectoristurnedtoanoperatingpositionandwhenmodeselectorreturnstooffwhenreleased,checkthefollowing:1.Triplever.If gummy,remove,clean,andreplace.Besurethatspringisattached.2.Triplevers.topadjustment.Ifmachinefailstooperatewhenmodeselectoristurnedtoanoperating

24、positionandmodeseiectorremainsinthatposition,checkthefollowing:1.Masterswitchanditsadjustment.2,Turntablereversingswitchanditsadjustment.3.Topplatefuse.4.Powerswitchandtopplate wiring.Ifbrakingistoosevereorirregularthecauseisprobablyaforeigndepositonthebrakedrums.Cleandrumswithcarbontetrachlorid.oro

25、thersolvent.Thefeltliningsshould functionproperlyafterthedrumshave beencleaned.However,iftheyhaveinsomewaypickedupoiltheyshouldbe.replaced.Iftherubbertiredturntable drivewheelslipsonthebrakedruminanymode,thesituationshouldbecorrectdimmediatelyastl!rubbertirewillbeinjured,andrubberwillbedepositedonth

26、brakedi1rnscausingbrakeandholdbackproblems.Checkthefollowing;1,Presenceofoilonbrakedrumsor.tire.2.Turntablemotorcenteringifslippageoccursinonlyonedirection3.Masterswitchadjustment.Iftapetendstowanderupordownfromengementbetweencapstanandcapstanidler,checkthefollowing1.Capstanidlerheight.2.Capstantape

27、guideheight.3.Playholdbacktensioneithertoogreatortoolight.4.Playresistorswitchnotcuttingin.5.Powerboostswitchadjustment.Withthemachineinplaymodethereshouldbeanextrasurgeofpowerasthe takeuptensionarmisforciblymovedinagainstthetape.Ifthissurgedoesnotoccurbeforethemachineshutsoffduetothetakeuptensionar

28、mbeingpushedtowardtherestoroffposition,thenthemachinecannotoperatesatisfactorily.Checktheplayresistorswitchand powerboostswitchforproperadjustmentandifnecessarymakefurtherchecktodeterminethattheswitchesarefunctioning.MODEL400MECHANICALADJUSTMENTMANUALSECTIONIIIA.BRAKELEVERPIVOTS-FIG,1-20Ifforanyreas

29、onthebrakeleversareremoved,replaceinsame.positionfromwhichtheywereremoved.Tightenlocknut,Fig.1-20,untilit bottomsonthebrakelever,thenbackoffapproximately1/4turn.Allownodragonthebrakeleveratthis point.B.BRAKERELEASEARMRESETSTOP-FIG1-81.Placemodeselectorinoffposition.2.Loosensecuringscrew,Fig.1-8Aands

30、etstop sothatthetriggeringendof thebrakereleasearm9Fig.1-7,isapproximately1/16fromthebrakereleasearm triggerendstop,Fig.1-7B.3.Tightensecuringscrewusingcaretoavoidmovingstop asscrewistightened.C.TRIPLEVER STOP-FIG,1-41.Fastentakeuptensionarminoperatin,positionwithScotch tape.2.Loosenstopsecuringscre

31、w,Fig.1-4A,andturnstoptoapositionthatwillallow3/64to1/16contactbetweenthetriggerendofthebrakereleaselever,Fig.1-7,andthetriplever,Fig.1-5,asthmodeselectoristurnedfromofftowardeitheroperatingposit.3.Tightenstopsecuring screw.D.FASTFORWARDANDREWIND HOLDBACK-FIG.2-8and241.Removebrakedrums.Notepositions

32、othateach drummasplacedontheshaftfromwhichitwasremoved.2.Therewindandfastforwardholdbackarms,Fig.2-8and24.have arestposition2-3/4inchesfromtheturntableshaft,Bend.a.apointclosetotheirmountingstocorrectanymisadjustinent.Besurethat linings contactdrumsevenlyanddonotbearheavilyorheelortoeoflining.E.BRAK

33、ES-FIG.1-10and151.Swingtakeuptensionarmontopplatetooperating positionandfastenittherewithScotch tape.2.Turnmodeselectortoeitheroperatingposition.3.Loosensetscrewonrewind brakeadjustmentcollar,Fig.1-9,adadjustbrakeshoetohaveminimumclearancefrom drum,Tightensetscrew.Checktodeterminebrakedoesnot,drag.4

34、Loosensetscrewontakeupbrakeadjustu,ncllarandadjust.brakeshoetoclearbrakedrumby1/32TietacrewF.MASTERSWITCHADJUSTMENT-FIG.1-191.Fastentakeuptensionarminoperating positionwithScotchtape.2.WiththePlaybuttondepressed,movemodeselectorinforwarddirectionuntilmasterswitch timinblineoncamfollowerarm linesupwi

35、ththeedgeofthemodechangecamas showninFig.1-21.3.Setmasterswitchtoclickatthispointbyadjustingpositionofthemasterswitchactuator,Fig.1-17.Fineadjustmentsmaybemadebybending themasterswitchtongue,Fig.1-18,slightly.4.Tightensetscrewinthemasterswitchactuatorandrechecktoseethatthemasterswitchclicksjustasthe

36、edgeofthecamlinesupwiththemasterswitch timingline.Alwaysperformthischeckinplaymode,G,PLAYENGAGEADJUSTMENTAlwayscheckmasterswitchadjustmentseeprecedingparagraphbeforemakingthisadjustment.1.Fastentakeuptensionarminoperating positionwithScotchtape.2.Adjustcapstan idleradjustmentclamp screw,Fig.2-19,tog

37、ivemediumdragbetweencapstan idleradjustmentarm,Fig.2-21,andcapstan idler armshaft,3,DepressPlaybuttonandmovemodeselectorinforwarddirectionuntilmasterswitchclicks.Shiftthecapstanidlerarm,Fig.2-20,withrespecttothecapstan idleradjustmentarm,Fig.2-21,sothatthecapstan idlerFig.2-17isabout1/64 fromthecaps

38、tan,Fig2-16,asthemasterswitchclicks.4.Securelytightencapstan idleradjustmentarmclamp screw,Fig.2-19.5.RecheckbydepressingPlaybuttonandmovingmodeselectorinforwarddirection.ThemasterswitchshouldclIckasthecapstanidlerreachesapointabout 1/64fromthecapstan.Donotallowthecapstan idlertotouchthecapstanbefor

39、ethemasterswitchclicksH.TURNTABLEREVERSINGSWITCH-FIG.2-31.Loosen clampboltonbellcrank,Fig,2-5A;2.WithmodeselectorinOffposition,rotateswitchswitchrotorbladesarecenteredintheswitch,3.Tightenbellcrankclampbolt.shiftuntiltheIfthemodeselectordoesnotsecurelylockinbothpositionswhenthe takeuptensionarmishel

40、dinoperatingposition,itis probablybecauseofmisadjustmentofthisswitchThestopontheswitch iscausingaprematurestoppageofthecamReadjustslightlytocorrectthiscodi.tion.I.TURNTABLEMOTORCENTERING-FIG,2I.Removeturntablemotolink,Fig.26,mbellcrank.Fig.2-5.2.Holdthe.turntablemotorcenteredaccuratelybetweenthebrak

41、edrums.Asimplecenteringjibcouldconsistoftwopiecesof1/16thickmetalinsertedbetweenbrake drumsandturntablemotortire.3Revolvetheturntable motor link,Fig2-6,untilitlinesupwiththeoutside holeinthebellcrank,Fig2-54.InsertturntablemotorlinkfromcastingsideandinstallnewretainingringJ.POWERBOOSTERSWITCHADJUSTM

42、ENT-IG.1-161.Movethetakeutensionarmfromitsrestoroffpositiontowardthereelidler,Thepowerboostmicroswitchshould clickoropenasthearmguidepassesthrougha linedrawnbetweenthecenterofthereelidlerandthecenterofthe takeuptensionarm bearing.2.Ifnecessary,adjustbybending themicroswitcharmslightly.K.TAKEUPTENSIO

43、NARMTENSION-FIG.1Theamountoftensiongiventothetakeuptensionarmisimportant.Anamountjustsufficienttotripthemechanismshouldbemaintained.Ifexcessiveitwillcausethemachinetoshutoffduringrewindorfastforwardandcausestartingdifficulties.Forrackmounting,additionaltensionhastobeprovidedtocompensatefortheweighto

44、fthetensionarmAdjustmentisaccomplishedbylooseningthelocknutatthecamfollowingarmpivot,Fig.1-6A,and movingtakeuptensionarmadjustmentlug,Fig.1-6,toobtaincorrecttension.Forrackmountingitmaybenecessarytoshortenspringtosecuresufficienttension.L,PLAYRESISTORSWITCH,RECORDINTERLOCKSWITCH ANDPLAYHOLDBACKADJUS

45、TMENT1.Faste.ntakeuptensionarminoperating positionwithScotchtape.2.Connectohmmeteracrosstheoutsideterminalsofplayiesistr,Fig.2-15,usingalowresistancerange,todetermineexacttimeofplayresistorswitch action.3.Playholdbackactuator,Fig.2-12,shouldbeinapproximatelynormal positiononshaft.4,Loosenclampscrewo

46、nswitchactuator,Fig.2-25,butmaintainslightdrag.5Moveswitchactuator,Fig2-25,ontheswitchshaftothattheresistorcutsinafterthemasterswitchclickasthemodeselectoris movedintheforwarddirectionwiththeplaybuttondepressedResistorshouldcutinwhenpositionofthemodeche.ngecamandcamfollowerareas showninFig36Withmach

47、ineinPlaymode,readjustplayholdbackactuatorasshowninFig2-12untilitpressestheentire surfaceoftheplayhdbackfeltevenlyontheholdbackbrakdrumPlayhod,bakshouldbe4oz,measuredwithrecorderinPlaymodeandfromN. A. B.hub,Reel sizeswitchshouldbeinlargereelposition.Securelytightenclampscrewwhenadjustmentiscompleted

48、.7.Recheckplayresistorandrecordswitch,BesuretheplayresistorswitchiscorrectlyadjustedasinParagraph5,above,Recordinterlockswitchadjustmentisalsoaccomplishedbythisprocedure.M.PLAYTAKEUPADJUSTMENTTheslideontheplayresistor,Fig.2-15,adjuststheplaytakeup.Movingtheslidetowardthetopplateincreasesthetakeup.To

49、checkforpropertension:1.Fastentakeuptensionarminoperating positionwithScotchtapeand withtransportmechanisminnormal positionandpowerconnected.2.Attachashortpieceofstringabout30tothetakeupreelhubN.A.B.withtheotherendattachedtoaspringscaleOr16oz,preferred.3.PlacethemachineinPlaymode.4.Thetensionshouldb

50、e8-1/2to9oz,asthescaleisallowedtomoveslowlyinthedirectionofpullofthereel.N.REELIDLERHEIGHTTheheightofthetapeabovethetopplate isdeterminedbythetapeguidesintheheadhousing.Itshouldbeapproximately3/4inches,measuringfromthebottomofthetapetothesurfaceofthetopplateSAdjustmentofreelidlerheightismadebyloosen