Ampex-401-tape-sm维修电路原理图.pdf

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1、1,MODEL401MAGNETICmaRECOISDEHHOLLYWOOD&VINEP0BOXZastHOLLYWOOD28CALIFDKPTTO:rCRS.SOcpLacbaOOttEECTRONftIIRadioFans.CN 收音机爱 好者资料库MODEL401The Model401isidenticaltotheMade-I400ineveryrespectexcepttheheada-s-sembly.The401incorporate-s-headsto-eraseandre-cordover-thefullwidthofthetape.Thustapesrecordedont

2、he401canbeplayedbackontheModel300andModel201withoutpreerasingtheunusedportionofthetapeandwithoutnecessitatinglevel adjustment.TheInstallation&OperationManualoftheModel400whichfollowsappliesinallrespectsotherthanthe halftrackrecordfeatures.Boththe400and401willplaybackeitherfullorhalftrackrecordingsre

3、cordedonanyAMPEXrecorder.RadioFans.CN 收音机爱 好者资料库ISSUENUMBER3EFFECTIVESERIAL#2722AMPEXMODEL400INSTALLATION&OPERATIONMANUAL-IndexofSECTIONS,CIRCUITSANDDRAWINGSSECTIONISPECIFICATIONSSECTION11INSTALLATIONSECTIONUIOPERATIONSECTIONIVHEADASSEMBLYANDSPECIALPRECAUTIONSINUSESECTIONVELECTRONICALIGNMENTSECTIONV

4、IMAINTENANCESECTIONVIIPARTSLISTS4NDSTOCKNUMBERSFIGURE1ELECTRONICSCHEMATICDIAGRAMFIGURE2POWERSUPPLYSCHEMATICDIAGRAMFIGURE3CONTROLCIRCUITSFIGURE4CONNECTIONDIAGRAMFORHIGHIMPEDANCEMICROPHONEFIGURE5CONNECTIONDIAGRAMFOR30AND50OHMMICROPHONESFIGURE6TOPPLATEFIGURE7ELECTRONICASSEMBLYFRONTPANELFIGURE8ELECTRONI

5、CASSEMBLYTOPVIEWFIGURE9MECHANICALLINKAGE3-12-51SPECIFICATIONS-MODEL400TapeSpeed.15inches persecondand7.5inches persecond,withmotorspeedchangeandequalizationswitchesconvenientlylocated.FrequencyResponseAt15inches+2db.50-15,000cyclesAt7i/ainches4-2db,70-10,000cycles+4db.30-15,000cyclesSignal-to-NoiseR

6、atio.Over55db.atboth7l/Zinchespersecondand15inchespersecond,asdefinedbytheN. A. B.standards.Bydefinition,thesignal-to-noiseratioistheratioofpeakrecordinglevelto-thetotalunweightedplaybacknoisewhenerasingasignalofpeakrecordinglevelandintheabsenceofanewsignal.Thus,biasanderasenoiseareincluded,aswellas

7、playbackamplifier noise.Allfrequenciesbetween30and15,000cyclesare measured.Thepeakrecordinglevelis definedasthatlevelatwhich theoverallinputtooutputtotalr.m.s.harmonicdistortiondoesnotexceed3%whenmeasuredona400cycletone.StartingTime.Instantaneous.Whenstartingthetapeacceleratestofullspeedinlessthani/

8、iosecondbecausecapstanmotoroperateswheneverpowerison.StoppingTime.Whenplayingatl5inches persecond,thetapemoveslessthan2inchesafterstopswitch isoperated.FlutterandWow,AtlSi.p.s.wellunder2/10%r.m,s,measuringallfluttercomponentsfrom0to300cyclesusingatoneof3,000cycles.At71/2inchespersecondunder 1/4%.Pla

9、ybackTimingAccuracy.2/10%.PlayingTime.32minutesat15inch speedwithstandardN. A. B.reel;64minutesat7.5inch speedoneachtrack.ThestandardR.M.A.reelmayalsobeused.TheModel400MagneticTapeRecorderis designedtorecordononlyone-halfofthestandard1/4widetapeinaccordancewithR.M.A,standards,Byturningthereelovekand

10、recordingontheotherhalf,twicetheamountofprogramcanbestoredonasinglereel,therebyeffectinga50%savingintape.RewindTime.OneandahalfminutesforthefullN,A.ree1Model4-jQSectionIPage1OperationSelector.Asingleselectorcontrolleverisused forFASTFORWARD,PLAY,STOP,andREWIND.Aseparaterecordbuttonenergizesrecordrel

11、ay,whichdropsout whenmachineisstopped.Shuttlingbackandforthoftapemadepossiblebychangingfromonemodeofoperationtotheother.CompletePlug-InHeadHousing,Erase,record,andplayback headsarecontainedinasingleplug-inheadhousing.SimultaneousMonitoring,Separaterecordandplaybackamplihersandheadsallowthetapetobemo

12、nitoredwhilerecording.Input.Aswitch allowstherecordertoaccommodateeithermicrophonelevellowimpedanceinputortobridge600ohmsplus4VUlinebalancedorunbalanced.PlaybackAmplifier.Plus4VUoutputinto600ohmsbalancedorunbalanced.Metering.A4inchVUmeterismountedonthefrontpanelandprovidesfor:a.Directmonitorofrecord

13、inputsignalbeforeorduringrecording.b.Monitorofrecordedoutputsignalfromplaybackheadwhilerecordingorduringplayback.c,Readingbiascurrent.d.Readingerasecurrent.PhoneMonitoring.Aphonemonitorjack isprovidedfordirectmonitorofrecordinputsignalbeforeorduringrecording,andmonitorofrecordedoutputsignalfromplayb

14、ackheadwhilerecordingorduringplayback.AnA-Bswitchisincorporatedinorderthatdirectcomparisoncanbemadebetweentheoriginalprogramandtherecordedprogramwhilearecordingisbeingmade.ThesameswitchtransferstheVUmeterforlevelcomparisonandmonitoring.Mountings.Rackorportablecase,Dimen sions.Mechanicalunitismounted

15、on153/4panelforstandardrackmounting.Electronicunitismountedon7panelforstandardrackmounting.Powersupplyisona51/4 panelforrackmounting,ormountedintheportablecase,PortablecaseholdingboththemechanicalModel400SectionIPage24-11-51unitandtheelectronicassemblyhasoveralldimensionsohapproximately133/4high,171

16、/2deep,and20wide.Weight.Approximately75poundsforcompleteunitinportablecase.Model400SectionIPage34-11-51INSTALLATIONIMPORTANT:Beforeattemptingtooperatetherecorder,firstreadthefollowingsectionsoninstallationandoperation.Theportablemachineisshippedinaready-to-operatecondition.Therackmountedmachineshoul

17、dbemountedonastandard19relayrackwiththemechanicalunitabovethemainelectronicpanel.Theelectronicpowersupply panelshouldbemounteddirectlyabovethemechanicalassembly,oratleast5below theelectronicassembly.Greaterproximitytotheelectronicassemblywillresultinincreasedhumlevel.Forfurtherinformationonrackmount

18、ing,seePage3ofthissection,Allconnectionsarereadilyaccessiblefromthefrontpanel.Releasethefrontpanelcoverby unlatchingandremovingthe topcover.ThenumberssetoffinparenthesesinthefollowingtextrefertothenumbereddesignationsinFig.6andFig.7.I.OUTPUT:A.ForStudioLine:Plus4VU,600ohmlineoutput,balancedorunbalan

19、ced,isavailableacrossterminals2and3of theLINEOUTconnector,12.Pin1isthechassisground.Ifunbalancedoutputisdesired,tieeithersideofthelinetoground.Itisnecessarytosupply600ohmterminationtothisoutputaalltimesinordertomaintaincorrectmetercalibrationwhilerecordingor playingback.Therefore,iftheoutputisnot fe

20、edingaterminatedlineorif theoutputisnotconnected,suchasonremotepickups,theLINEOUTPUTTERMINATIONswitch,13,mustbeswitchedtoIN.B.ForConnectiontoHighImpedanceAmplifierInput:Connectpin3oftheLINEOUTconnector,12,tothehighsideoftheamplifierinput.Strappins1and2oftheconnectorandconnecttothegroundsideof theamp

21、lifierinput.The LINEOUTPUTTERMINATIONswitch,15,mustbeleftinthepositiondesignatedINatalltimes,asexplainedinAabove.Model400SectionIIPage13-26-51II.INPUT:Thefollowing inputsareprovided:A.Microphones:Anylowimpedancemicrophone,thenominal impedanceofwhichisintherangeof30to250ohmscanbepluggedindirectly.Con

22、nectmicrophonetopins2and3oftheinputconnection,14.Connect cableshieldtopin1.PlacetheINPUTTRANSFERSWITCH,15,intheMICposition.Themicrophoneinputtransformerisstrappedfortheoptimumstepupfora150to250ohmsource.Therefore,inthecaseofmicrophoneshaving50ohmsorlessimpedance,6db.additionalgaincanbeobtainedbystra

23、ppingtheinputasshowninFig.5.Thisisnotusuallynecessary,however,andshouldnotbedoneunlessinsufficientgainisfoundto exist.Iftheinputisre-strapped,seriousfrequencydiscriminationwillexistshouldtheinputbefedfromasourceimpedancegreaterthan50ohms.Highimpedancemicrophonesarenotrecommendedforuseonthisequipment

24、.Ingeneral,thequalityobtainablefromhighimpedancemicrophonesisnotsatisfactoryforprofessionalwork.Intheeventthatitbecomesnecessarytoconnectahighimpedancemicrophone,theinputcircuitwillhavetobere-wiredasshowninFig.4.B.BridgingaBalancedStudioLine:Connectbalancedlinetopins2and3oftheinputconnector,14.Pin1i

25、sground.PlacetheINPUTTRANSFERSWITCH,15,intheSALBRIDGEEdsition.Inputlevelsofminus10toplus10VUcanbeaccommodated.Theloadplacedonthe lineis approximately100,000ohms.If theinputtransformerisrestrappedfor50ohms,theinputlevelaccommodatedonthebalancedbridgepositionisminus16toplus4VU.Forbridginghigherorlower

26、levellines,anexternalbridgecanbewiredinthe linetothemachine.Thiswouldconsistof aresistance,thevalueofwhichshouldbe50,000timesti.RMSprogramvoltage,inserieswitheachsideoftheline,A 50ohmresistorshouldterminatetheoutputsideofthetwobridgingrest.tors.Theoutputofthebridgemustbefedtothemicrophoneinputfthere

27、corder.C.BridginganUnbalancedSourceConnectunbalancedline,radiotu:.r,etc.,topins3and1ofModel400SectionIIPage2theinputconnector14.Pinusthegroundside.PlacetheINPUTTRANSFERSWITCH,15,intheUNBAL.BRIDGEposition.Thisconnection,rovides100,000ohmsbridgingofanyRMSprogramvoltagegrcaterthani/avolt.III.PHONES:Any

28、sensitivehighimpedanceheadphonescanbepluggedinthejack11,providedformonitoringofincominglineorplaybackoftherecording.IV,RECOMMENDEDRACK MOUNTINGOFTWOMACHINES:Iftwo400sor4Olsaretobemountedonastandardrack,thefollowingplacementisrecommendedstartingatthetopof therack:1.Installa13/4inchspacerpanelatthe to

29、pof therack.2.InstallbelowthispaneltheMechanicalAssemblyformachine#1.3.InstalltheElectronicAssemblyformachine#1.4.Installa13/4inchor3i/ainchspacerpanel.5.InstalltheMechanicalAssembly#2.6,InstalltheElectronicAssembly#2.7.Installa51/4inchor7inchspacerpanel.S.Installbothpowersupplypanelsatthebottom.The

30、cableonthepowersupplyfortheupper.recorderwillhavetobe:vtendcdinlength.Itisimportantthatnopowersupplybecloserthan5inchestoanElectronicAssembly!Model400SectionIIPage33-26-SiOPERATION-MODEL400I.REEL SIZE:TheturntableontheleftsidetapesupplyisequippedtohandleeithertheN. A.B.10u/areeloftape orthesmallerR.

31、iv!.A.5and7inchsizes.Handlingthesedifferenttypereelsonthisturntablecanbeaccomplishedas follows:1N, A.B.-10i/aReel-PlacetheReelSizeSwitch6intheLargepositionandplacethereelontheturntableafterpositioningtheblackplasticreelcenteringguidethathas beenprovided.2R.M.A.-7 &5Reels-PlacetheReelSizeSwitch6inthe

32、Smallpositionandplacethereelonthekeyedturntabledirectly.TheturntableontherightsidetakeupreelwillhandleonlytheN. A.B.101/2reelandthe keyshavenotbeenprovidedontheturntabletodrivethesmallreels.AttemptingtousethesmallR.M.A.reelsontherighthandtakeupturntablewillseriouslyimpairtheperformanceof themachine.

33、II.TAPETHREADING:Threadtape asindicatedinFig.6.Thetakeuptensionarm,5,mustbemovedintopositionasshown,inordertosupplypowertooperatethemachine.III.POWER:Powerissuppliedtothetopplatethroughswitch,3,whichmustbeturnedontoenergizethemotors,Mainpowerissuppliedthroughswitch,9,whichmustbeturnedontooperatethee

34、lectronicsandtopplate.Thetopplateandelectronicsareindividuallyfusedby7and8,respectively.IV.FUSES:TopPlateFuse72AmperesChassisFuse81AmpereV.SPEEDSWITCHES:Therearetwoswitchesassociatedwithoperatingspeed.Switch4governsthemotor,and19correctsequalizationintheamplifiers.VI.TAPEMOTION:Thetapemotioniscontro

35、lledbymeansofamodeselectorswitch1andthePLAYbuUei2,directlytoitsleft.Theselectorswitch shouldbemovedfirmlybymeansof theselectorknobattached,Hold the knobsecurelybetweenthethumb andforefingerwhilechangingitsposition.Rapid,positivemotionof theselectorknobisrecommendedinpreferencetoslowaction,Thisistoin

36、suresimultaneousactionofallnecessaryfunctions.Model400SectionIIIPage13-12-51-IMPORTANT-Thetripoutswitchwillnotdisengagethecapstan idlerattheendofthereelunlessthetapewillfreelydisengagethereelhub.Allnewfactorywoundreelsoftapeshouldbeunwoundandinspected,astheyareusuallyloopedtothehubinamannersuchthatt

37、heywiiinotcomefree.Ifthetapedoes notdisengagethereel,thedrivecapstanwillwearaflatintherubbercapstan idlerwheelwhichwillnecessitatethewheelsreplacement.Anyadhesivematerialaccumulationonthehubmustberemovedwithsolventforthesamereason,1.PlayandRecord,ThetapeissetintoplaymotionbyfirstdepressingthePLAYbut

38、ton,2,and thenmovingtheselectorswitch,1,totheFORWARDposition.Itis importantthatthePLAYbuttonbedepressedbeforemovingtheselectorswitchorthetapewillmoveatthefast forwardspee;dinsteadofattheoperatingspeed.Thetapemustbecompletelystoppedbeforestartinginthismode.Theselectorswitchshouldbemovedfirmlyandrapid

39、lytoinsureproperoperation.2,Stop.Tostopthetapemotion,whileitismovinginanymode,merelyreturntheselectorswitch,1,totheOFFposition,Thiswilloccurautomaticallyifthetapeshouldbreakorrunoffofeitherreel,CAUTION:Neverstopthemachineneartheendof afastwindwhenusingthesmallreel,butallowthetapetorunoff,Whentheamou

40、ntoftaperemainingontheunwindingreelislessthan1/2;therateofrotationofthereelbecomessogreatthatitmaynotstopwithoutthrowingaslackloop.3,FastForward,Movetheselectorswitch,1,towardtheleftwithoutdepressingthebutton,Thisisafa?t forwardspeedwhichisusedinordertorapidlyarriveatapoint withinthereel,4,Rewind,Mo

41、vetheselectorswitch,1,towardtheright.Thisisafastreverseandisusedtorewindthetape completelyortoreturntoanearliersectior,usingeitherthefastforwardorrewindmode,itis desirabletoremovethetapefromdirectcontactwiththeheadsbyopeningthegateoftheheadassembly,Thisistopreventoxidecoatingfromdepositingontheheads

42、andimpairingtheperformance,andreduceswearontheheads,Inputtingtherecorderintoplayorfast forwardimmediatelyafterfastrewind,slackinthetapemay occLrcausingtherecordertotripoff,Inthiscase,returnthemode.electortooff,takeuptheslackinthetape,andthemachinewillfunctionnormally.Theconditionisbroughtaboutbythet

43、urntablemotorspinningfreeforashorttimeinModel400SectionIIIPage24-11-51thedirentinnitwaslastrimning.Theoperatorwillfindanumberofwaystoavnisid.eiay.dnetothiscondition.Oneofthesimplestjstomovethemodeselectorafewdegreesinthedirectionthemachinewaslastrunningbefore,proceedinginthedesiredmode.VII.PLAYBACK:

44、Toplaybackapreviouslyrecordedtape,turntheMST.ERand OUTPUTswitc.h,20,totheextremeleftpositiondesignatedPL&Y.BAilIC.ThenstartthetapeinmotionasindicatedunderPlay.Iftherecordingwasmadeatthecorrectlevel,theVUMeterwillpeakonozero.Noattemptshouldbemade toalterthegainoftheplaybackamplifierifthemeterdoesnotp

45、eakon0zero.Otherwise,thecalibrationafthismeterasarecordlevelindicatorwillbedestroyed.TheplaybackgainwillbeclosewhenplayinganytaperecordedtoN.A.B.specificationsatl5?/sec.VIII,RECORD:Torecordanewprogramonpreviouslyrecordedtape,oronblanktape,turnswitch20tothesecondpositionfromtheleftwhichisdesignatedRE

46、CORD-LEVEL.TurntheRecordGaincontrol,16,clockwiseuntilthelevelreads0zeroontheVUmeteronthemostintenseprogrampeaks.Theprogramcanbeaudiblymonitoredthrougheithertheearphonesjack,io,ortheLINEOUTbeforethetapeisinmotion,Forcorrectmetercalibrationitis importantthattheLINEOUTbeproperlyterminatedeitherexternal

47、tothemachineorbyuseoftheLINEOUTPUTTERMINATIONswitch,13.See detailedinstructionsunderINSTALLATION.Thisdirectmonitorfeatureallowstheprogramtobesetupthroughthemachinewithoutactuallyrecordingduringthesetupperiod.Whentheprogramlevelisproperlyset,startthetape inmotionasindicatedunderPLAY.ThenpushtheRECORD

48、button,18.Besurethereisadelayofatleasti/asecondbefore operatingtheRECORDbutton,asthesurgefromoperatingthePLAYcontrolmaymagnetizetherecordhead,thereby increasingthenoiselevelonthetape.Therecordindicator917,abovetherecordbutton willnowglowandthemachineisrecording.Itis desirabletobhecktherecordbiasande

49、rasecurrentsoccasionally.Inordertodothis,repositionswitch,20,tothepositionsdesignatedBIASandERASE,respectively,Theeraseisnotcriticalandshouldreadintheupperhalfofthemeterscale,Thebiasonthismachine,serial#2701andafter,shouldreadbetween-1/2andFl/aontheVUscale,Thebiasissomewhatcriticalandmustbekept with

50、intheindicatedrangeinordertorecordthehigherfrequenciesat71/?inchtapespeed.Thebiasisadjustedbymeansofthelockedcontrol,11.Themetercalibrationforbiasmeasureme:itcanbecheckedasindicatedinelectronicalignment.Anactual comparisonoftherecordingwiththedirectprogramModel400SectionIllPage32-16-51canbemadebotha