Ampex-401-tape-sm维修电路原理图.pdf
1, MODEL401 MAGNETICma RECOISDEH HOLLYWOOD 64minutesat7.5inch speedoneachtrack.ThestandardR.M.A.reel mayalsobeused.TheModel400MagneticTapeRecorderis designedto recordononlyone-halfofthestandard1/4widetapeinaccordancewith R.M.A,standards,Byturningthereelovekandrecordingontheother half,twicetheamountofprogramcanbestoredonasinglereel,thereby effectinga50%savingintape. RewindTime.OneandahalfminutesforthefullN,A.ree1 Model4-jQSectionIPage 1 OperationSelector.Asingleselectorcontrolleveris used for FASTFORWARD,PLAY,STOP,andREWIND.A separaterecordbutton energizesrecordrelay,whichdropsout whenmachineisstopped.Shutt lingbackandforthoftapemadepossiblebychangingfromone modeof operationtotheother. CompletePlug-InHeadHousing,Erase,record,andplay back headsarecontainedinasingleplug-inheadhousing. SimultaneousMonitoring,Separaterecordandplaybackampli hersandheadsallowthetapetobemonitoredwhilerecording. Input.Aswitch allowstherecordertoaccommodateeithermicrophone levellowimpedanceinputortobridge600ohmsplus4VUlinebalanced orunbalanced. PlaybackAmplifier.Plus4VUoutputinto600ohmsbalancedor unbalanced. Metering.A4inchVUmeterismountedonthefrontpanelandpro videsfor: a.Directmonitorofrecordinputsignalbeforeorduringrecording. b.Monitorofrecordedoutputsignalfromplaybackheadwhilere cordingorduringplayback. c,Readingbiascurrent. d.Readingerasecurrent. PhoneMonitoring.Aphonemonitorjack isprovidedfordirect monitorofrecordinputsignalbeforeorduringrecording,andmonitorof recordedoutputsignalfromplaybackheadwhilerecordingorduringplay back. AnA-Bswitchisincorporatedinorderthatdirectcomparisoncanbe madebetweentheoriginalprogramandtherecordedprogramwhileare cordingisbeingmade.ThesameswitchtransferstheVUmeterforlevel comparisonandmonitoring. Mountings.Rackorportablecase, Dimen sions.Mechanicalunitismountedon153/4panelforstand ardrackmounting.Electronicunitismountedon7panelforstandard rackmounting.Powersupplyisona51/4 panelforrackmounting,or mountedintheportablecase,Portablecaseholdingboththemechanical Model400SectionIPage 24-11-51 unitandtheelectronicassemblyhasoveralldimensionsohapproximate ly 133/4high,171/2deep,and20wide. Weight.Approximately75poundsforcompleteunitinportable case. Model400SectionIPage 34-11-51 INSTALLATION IMPORTANT: Beforeattemptingtooperatetherecorder,first readthefollow ingsectionsoninstallationandoperation. Theportablemachineisshippedinaready-to-operatecondition. Therackmountedmachineshouldbemountedonastandard19 relayrackwiththemechanicalunitabovethemainelectronicpanel.The electronicpowersupply panelshouldbemounteddirectlyabovethemechan icalassembly,oratleast5below theelectronicassembly.Greaterprox imitytotheelectronicassemblywillresultinincreasedhumlevel.For furtherinformationonrackmounting,seePage 3ofthissection, Allconnectionsarereadilyaccessiblefromthefrontpanel.Re leasethefrontpanelcoverby unlatchingandremovingthe topcover.The numberssetoffinparenthesesinthefollowingtextrefertothenumbered designationsinFig.6andFig.7. I.OUTPUT: A.ForStudioLine: Plus4VU,600ohmlineoutput,balancedorunbalanced,isavail ableacrossterminals2and3of theLINEOUTconnector,12.Pin1is thechassisground.Ifunbalancedoutputisdesired,tieeithersideofthe linetoground.Itisnecessarytosupply600ohmterminationtothisoutput aalltimesinordertomaintaincorrectmetercalibrationwhilerecording or playingback.Therefore,iftheoutputisnot feedingaterminatedline orif theoutputisnotconnected,suchasonremotepickups,theLINEOUT PUTTERMINATIONswitch,13,mustbeswitchedtoIN. B.ForConnectiontoHighImpedanceAmplifier Input: Connectpin3oftheLINEOUTconnector,12,tothehighsideof theamplifierinput.Strappins1and2oftheconnectorandconnecttothe groundsideof theamplifierinput.The LINEOUTPUTTERMINATION switch,15,mustbeleftinthepositiondesignatedINatalltimes,asex plainedinAabove. Model400SectionIIPage13-26-51 II.INPUT: Thefollowing inputsareprovided: A.Microphones: Anylowimpedancemicrophone,thenominal impedanceofwhich isintherangeof30to250ohmscanbepluggedindirectly.Connect microphonetopins2and3oftheinputconnection,14.Connect cable shieldtopin1.PlacetheINPUTTRANSFERSWITCH,15,intheMIC position. Themicrophoneinputtransformerisstrappedfortheoptimum stepupfora150to250ohmsource.Therefore,inthecaseofmicro phoneshaving50ohmsorlessimpedance,6db.additionalgaincanbe obtainedbystrappingtheinputasshowninFig.5.Thisisnotusually necessary,however,andshouldnotbedoneunlessinsufficientgainis foundto exist.Iftheinputisre-strapped,seriousfrequencydiscrim inationwillexistshouldtheinputbefedfromasourceimpedancegreat erthan50ohms. Highimpedancemicrophonesarenotrecommendedforuseon thisequipment.Ingeneral,thequalityobtainablefromhighimpedance microphonesisnotsatisfactoryforprofessionalwork. Intheeventthatitbecomesnecessarytoconnectahighimpedance microphone,theinputcircuitwillhavetobere-wiredasshowninFig.4. B.BridgingaBalancedStudioLine: Connectbalancedlinetopins2and3oftheinputconnector,14. Pin1isground.PlacetheINPUTTRANSFERSWITCH,15,intheSAL BRIDGEEdsition.Inputlevelsofminus10toplus10VUcanbeaccommo dated.Theloadplacedonthe lineis approximately100,000ohms. If theinputtransformerisrestrappedfor50ohms,theinput levelaccommodatedonthebalancedbridgepositionisminus16toplus 4VU. Forbridginghigherorlowerlevellines,anexternalbridgecan bewiredinthe linetothemachine.Thiswouldconsistof aresistance, thevalueofwhichshouldbe50,000timesti.RMSprogramvoltage,in serieswitheachsideoftheline,A 50ohmresistorshouldterminate theoutputsideofthetwobridgingrest.tors.Theoutputofthebridge mustbefedtothemicrophoneinputftherecorder. C.BridginganUnbalancedSource Connectunbalancedline,radiotu:.r,etc.,topins3and1of Model400SectionIIPage2 theinputconnector14.Pinusthegroundside.PlacetheINPUT TRANSFERSWITCH,15,intheUNBAL.BRIDGEposition.Thiscon nection,rovides 100,000ohmsbridgingofanyRMSprogramvoltage grcaterthani/avolt. III.PHONES: Anysensitivehighimpedanceheadphonescanbepluggedinthe jack11,providedformonitoringofincominglineorplaybackofthere cording. IV,RECOMMENDEDRACK MOUNTINGOFTWOMACHINES: Iftwo400sor4Olsaretobemountedonastandardrack,thefol lowingplacementisrecommendedstartingatthetopof therack: 1.Installa 13/4inchspacerpanelatthe topof therack. 2.InstallbelowthispaneltheMechanical Assemblyformachine#1. 3.InstalltheElectronicAssemblyformachine #1. 4.Installa 13/4inchor3i/ainchspacerpanel. 5.InstalltheMechanicalAssembly #2. 6,InstalltheElectronicAssembly#2. 7.Installa 51/4inchor7inchspacerpanel. S.Installbothpowersupplypanelsatthebottom. Thecableonthepowersupplyfortheupper .recorderwillhave tobe:vtendcdinlength. Itisimportantthatnopowersupplybecloserthan 5inchesto anElectronicAssembly! Model400SectionIIPage 33-26-Si OPERATION-MODEL400 I.REEL SIZE:Theturntableontheleftsidetapesupplyis equippedtohandleeithertheN. A.B.10u/areeloftape orthesmaller R.iv!.A.5and7inchsizes.Handlingthesedifferenttypereelsonthis turntablecanbeaccomplishedas follows: 1 N, A. B. -10i/aReel-PlacetheReelSizeSwitch6in theLargepositionandplacethereelontheturntableafterpositioning theblackplasticreelcenteringguidethathas beenprovided. 2R.M.A.-7 dinsteadofattheoperatingspeed.The tapemustbecompletelystoppedbeforestartinginthismode.These lectorswitchshouldbemovedfirmlyandrapidlytoinsureproperopera tion. 2,Stop.Tostopthetapemotion,whileitismovinginany mode,merelyreturntheselectorswitch,1,totheOFFposition,This willoccurautomaticallyifthetapeshouldbreakorrunoffofeitherreel, CAUTION:Neverstopthemachineneartheendof afastwind whenusingthesmallreel,butallowthetapetorunoff,Whentheamount oftaperemainingontheunwindingreelislessthan1/2;therateofro tationofthereelbecomessogreatthatitmaynotstopwithoutthrowing aslackloop. 3,FastForward,Movetheselectorswitch,1,towardthe leftwithoutdepressingthebutton,Thisisafa?t forwardspeedwhichis usedinordertorapidlyarriveatapoint withinthereel, 4,Rewind,Movetheselectorswitch,1,towardtheright. Thisisafastreverseandisusedtorewindthetape completelyorto returntoanearliersectior,usingeitherthefastforwardorrewind mode,itis desirabletoremovethetapefromdirectcontactwiththe headsbyopeningthegateoftheheadassembly,Thisistopreventoxide coatingfromdepositingontheheadsandimpairingtheperformance,and reduceswearontheheads, Inputtingtherecorderintoplayorfast forwardimmediatelyafter fastrewind,slackinthetapemay occLrcausingtherecordertotrip off,Inthiscase,returnthemode.electortooff,takeuptheslack inthetape,andthemachinewillfunctionnormally.Theconditionis broughtaboutbytheturntablemotorspinningfreefor ashorttimein Model400SectionIIIPage24-11-51 thedirentinnitwaslastrimning.Theoperatorwillfindanumberof waystoavnisid.eiay.dnetothiscondition.Oneofthesimplestjsto movethemodeselectorafewdegreesinthedirectionthemachinewas lastrunningbefore,proceedinginthedesiredmode. VII.PLAYBACK:Toplaybackapreviouslyrecordedtape,turnthe MST.ERand OUTPUTswitc.h,20,totheextremeleftpositiondesignated PLS%i I / I POWERSUPPLY _ C136 BOTTOMVIEW BOTTOMVIEW POWER 40051 .00 CABLE _ _ p NOTES:-7102TRANSPOWMERIMPEOANCECONNECTIONS I-ALL CAPACITIESIN MICROFARADS1<145MUSTBEADJUSTEDFOROUTPUT IMPEDANCE 2-FOR30SSOOHMSMICROPHONE ELECTRONICS 600 OHMSCONNECTTO156, JOIN3TO4 333OHMSCONNECTTO I 55,JOIN3TO4 SEEINSTALLATION - MODEL400 250OHMSCONNECTTO I S 6,JOIN2TO3APPRO. 200OHMS CONNECTTO255. JOIN3TO4 AMPEX ELECTRICCORPORATION 125OHMSCONNECT20ISIJOIN I TO3 64106 SAN CARLOS,CALIFORNIA SOOHMS INECTTO 264,JOIN2TO3 64705 POWERSUPPLY MODEL-400 AMPEXELECTRICCORPORATION SANCARLOS,CALIFORNIA VIEWOFPIN SIDE OF PLUGI C. B E SEE PICTORIALVIEW FOR PINNUMBERSORIENTATION H ASSEM. 0-1090 KEYWAYSLOT 1 C, U TURRETSOCKET JEOIP 1 - - DMOTORASSEM.B-IOSQJ 1 e C301 302 CABLE10ELECTRONICS PILOTLITE f U FASTSHUTTLESWITCH 1 C Cs 5306 0 RECOROINTERLOCKSWITCH CONTROLCIRCUITS MODEL-400 AMPEXELECTRIC CORPORATION SANCARLOS. CALIFORNIA FIG.4 INPUT FORHIGHIMPEDANCEMICROPHONE SEEINSTALLATION 0101 LOW CAPACITY CABLE SLTh= FIG.5 INPUTTRANSFORMERCONNECTION FOR TOGRID VIOl TO PLATE VIOl TORICe 30650OHMSMICROPHONES SEEINSTALLATION T MODEL-400 AMPEX ELECTRICCORPORATION SANCARLOS,CALIFORNIA -0 GROUND BUSS L REELCENTERINGGUIDE CAPSTAN HEADASSEMBLY -REELCENTERINGGUIDE TAKE-UPTENSIONARM MOTORSPEEDCHANGESWITCH STERPILOTLIGHT DRIVE MOTOR POWERSWITCH MODESELECTORSWITCH REELIDLER TOPPLATE MODEL-400 AMPEX ELECTRICCORPORATON SANCARLOS,CALIFORNIA TAPEGUIDE- CAPSTANIDLER 1 p a NORMAL-FORWARD-PLAY -TI p -J ELECTRONICS-FRONTPANEL MODEL-400 AMPEX ELECTRIC CORPORATION SANCA%,OS,CALIFORNIA J1O5-S JIOG- CI3G ERASECOUPLING J07-S dl FACTORY TUBE 120 I5v. VIOl 12547 a 0 5104 6C5 Lu p-P .4 .JC -Oj Q-o QOO E-t II uJ OO z I- c Xe Lii Lu _.j LU C R FIG.8 01Lr- SHOE LN!NG BRAKEDRUM TENSIONARM ADJUSTMENT DONOT OIL IC -it c-i zo C- Ui Oz 0-a: U C I_c Lii4 ,_IC- Iii 4 Xe Lii 0. C OIL FIG.9
