HP-650A-Manual-SN-6148 电路图.pdf

HP Archive This vintage Hewlett Packard document was preserved and distributed by Pleasevisituson the web! Scanned by on-line curator: Tony Gerbic * For FREE Distribution Only * RadioFans.CN 收音机爱 好者资料库 6S0A TESTOSCillATOR OPERATINGANDSERVICINGMANUAL RadioFans.CN 收音机爱 好者资料库 OPERATINGANDSERVICING MANUAL MODEL650A TESTOSCILLATOR SERIAL6148AND ABOVE TEST OSCu.ATOR .$. .-:WLLTT,ACAIlO 1lIlUt .1O XIOo- 50 XIOCKCfREUENCY CopyrightHEWLETT-PACKARDCOMPANY1956 275 PAGE Mll.L ROAD,PALOALTO, CALIFORNIA,U.S. A. 650A002-1/6-59 RadioFans.CN 收音机爱 好者资料库 FREQUENCY RANGE: SPECIFICATIONS 10cpsto10mc.Sixbands. FREQUENCY CALIBRATION:1.0to10.MultiplyingFactor x10cps xl00cps xlkc x10kc xlOOkc xlmc FrequencyRange 10to100cps 100to1, 000cps 1,000to10, 000cps 10to100kc 100to1,000kc 1to10 mc ) STABn.rry: OUTPUT: FREQUENCY RESPONSE: DISTORTION: OUTPUT MONITOR: OUTPUT ATTENUATOR: HUMVOLTAGE: POWER SUPPLY: DIMENSIONS: WEIGHT: ACCESSORIES FURNISHED: ACCESSORIES AVAn.ABLE: 2%, 10cpsto100kCj3%, 100kcto10mcincludingwarmup, 10%linevoltagevariations,andcalibrationerror. 15milliwattsor3voltsinto 600 ohmresistiveload.Opencircuit voltageisatleast6 volts. 600 ohmsourceimpedance. Sourceim- pedance of 6 ohmsavailablewhen 65A-16D voltagedividerisused. Within1 db, 10cpsto10mcinto600ohmresistiveload. Lessthan1%from20cpsto100 kc,lessthan2%from100kcto 1mc,approximately5%at10mc. Vacuumtubevoltmetermonitorslevelatinputtoattenuator,in voltsordbm.(Zerodbm=1 mwin600ohms.)Accuracy5% offullscalereading. 50dbin10dbsteps,providing continuooslyvariableootputvoltage from+12dbmto-50dbm,3voltsto3millivolts,(ordownto 30microvoltswithvoltagedivider).Accuracy1 db,intore- sistiveloadof 600ohms. Lessthan0.5%ofoutputsignalwithmeteratfullscale. 115/230volts10%,50-1000cps,165watts. CabinetMount:20-3/4wide,12-3/4high,15deep. RackMount:19wide,10-1/2high,13-3/4deep. CabinetMount:46lbs.,shipping66lbs. RackMount:37lbs.,shipping60lbs. Model65A-16DOutputCable(voltagedivider). ModelAC-16ACableAssembly,twodualbananaplugs. ModelAC-16BCableAssembly,dualbananaplugtoBNC. SECTION I CONTENTS GENERALDESCRIPTIONPage 1 - 1 1 - 2 1 - 3 General. Accessories Inspection I - 1 I - 1 I - 1 SECTIONITOPERATING INSTRUCTIONS 2 - 1 2 - 2 ControlsandTerminals. Operation. IT-1 IT- 2 SECTIONIIIcmCUITDESCRIPTION 3 - 1 3 - 2 3 - 3 3 - 4 3 - 5 3 - 6 3 - 7 3 - 8 Introduction. Oscillators BufferAmplifier ACVAmplifier OutputAmplifier OutputMonitor OutputAttenuator. PowerSupply ill- 1 ill-1 ill-2 ill-2 ill-2 ill-3 ill-3 ill-3 SECTION IVMAINTENANCE 4 - 1 4 - 2 4 - 3 4 - 4 4 - 5 4 - 6 4 - 7 4 - 8 CabinetRemoval. . LubricationofTuningCapacitorDriveMechanism DriveSystemforOscillatorTuningCapacitor TubeReplacement. MiscellaneousTestsandAdjustments CompleteTestProcedure. TroubleShooting. DriveCableReplacementProcedure IV -1 IV -1 IV -1 IV -1 IV - 3 IV -4 IV_12 IV-15 SECTIONVTABLEOFREPLACEABLEPARTS 5 - 1TableofReplaceablePartsV - 1 ) 1-1GENERAL TheHewlett-PackardModel 650ATestOscillatoris a widerangeprecisionresistancetunedoscillator covering from10cpsto10mc.Ithasa highlystable output signallevelthatisadjustablefrom30micro- voltsto3voltsinto 600ohms.Frequencyresponse isessentiallyflat(1 db)throughoutthecomplete extendedrange. The output impedanceisnormally600 ohms.Where a lowsourceimpedanceisdesired,6ohmsispro- videdbytheVoltageDividerCable supplied withthe instrument. TheModel650ATestOscillatoroutputvoltageis constantlymonitoredby avacuumtubevoltmeter attheinputtotheoutputattenuatorsystem.This VTVMhastwovoltmeterscalesplusadbmscale (0dbm=1milliwattin 600ohms).Theattenuator control, in conjunction with the AMPLITUDE control, willproduceamonitoredsignalof anydesiredlevel when the instrumentisresistiveloaded with 600ohms. The flexibility andsimplicityofthe650ATestOscil- latorfind a widevarietyofusesin audio, video,rf, and alignment applicationsaswellaslaboratorywide bandmeasurements.Thisinstrumentwasdesigned forsuchapplicationsasfastandaccuratetestingof filtertransmissioncharacteristics,tunedcircuit response,completereceiveralignment,telephone ortelegraphcarrierequipment,plusvideoand audioamplifiers. Sect. IPage1 SECTIONI GENERALDESCRIPTION TheModel 650ATestOscillatoriswellsuitedasa signalsourceforafandrfbridgemeasurements. Thewiderangeoftestfrequenciesnecessaryfor repairandtestingofelectronicfrequencycounters isalsoavailablefromthe650ATestOscillator. 1-2ACCESSORIES TheModel650ATestOscillatorissuppliedcomplete with a 65A-16D Output Divider Cable.The following accessoriesmaybepurchasedseparately: a.ModelAC-16A44inchCableAssembly. Equippedwithtwodualbananaplugshaving 3/4inchcenters.Madefrom50ohmcoaxialcable typeRG-58/U. b.ModelAC-16B45inchCableAssembly. SameasAC-16Aexceptonedualbananaplug isreplacedbyaUG-88/UtypeBNCmaleconnector. 1-3INSPECTION Carefullyexaminethisinstrumentforpossible shippingdamagebeforeandafterunpacking.Ifany shippingdamageisfound,refertoClaimfor DamageinShipment. ) ) 2-1CONTROLS ANDTERMINALS ON- Thistoggleswitchcontrolsthepowertransformer primarycircuit.WhenswitchisON,thecalibrated FREQUENCYdialisalsoilluminated. FREQUENCYRANGESWITCH- Thissix-positionrotaryswitchhasmarkingsof X10V,X100V,X1KC, X10KC, X100KC, and X1M. Thepositionofthisswitchindicatesthemultipli- cationfactorwhichmustbe appliedtothereadingof theFREQUENCYdialtodetermineoutputfrequency. FREQUENCY- Oscillatorfrequencyonanybandisdeterminedby rotatingthetwocontrolknobsunderthetuningdial. Theupperknobprovidescoarsetuningwhilethe lowerknobprovidesa 6to1mechanicalvernier forfinetuning. TUNING DIAL- Thetuningdialisaccuratelycalibratedfrom.9 through 10.ThedialreadingmultipliedbytheFre- quency Range Switchsettingistheinstrumentoutput frequency. R.M.S.VOLTS/DB- Thisrotaryswitchistheoutputattenuatorcontrol whichprovidessignallevelsfrom-40 dbmto+10dbm in10dbsteps.Thisswitchalsoindicatesvoltage acrossa 600 ohm load connectedtooutputterminals wheninstrumentoutputisadjustedfora fullscale voltmeterindication. Whenrotatedfullclockwisetheattenuatoriseffec- tivelyswitchedout ofthecircuit. AMPLITUDE- Thiscontrolpermitsadjustmentof inputleveltothe outputamplifierandtherebycontrolsinstrument outputlevel.Anydesiredoutputsignallevelbetween the 10dbstepsoftheR.M. S.VOLTS/DBselector switchcanbeobtained. Sect.IIPage1 SECTIONII OPERATINGINSTRUCTIONS OUTPUTMETER- Thismetercontinuouslymonitorsthesignallevel whenoperatinginto a 600 ohmresistiveload.Itin- dicatesasafullscaledeflectionthevalueofthe R.M. S.VOLTS/DBselectorswitchsetting.The meterisindicatedasM1ontheschematicdiagram andtogetherwithV16 andassociatedcomponents, constitutestheVTVMmonitorsection. 600S1- Theoutputterminalsareuniversalbindingpostson 3/4inchcenters.Theoutputsignalisdeveloped betweenthesetwoterminalswiththeonemarked Ggroundedtotheinstrumentchassis. FUSE- Thefuseholder,locatedonrearofchassis,contains a 2ampereslo-blofusefor115voltoperation. Ifinstrumentpowertransformerprimaryconnections have been changedfor230 volt operation, a 1ampere slo-blofusemustbeused. POWERCABLE- Thethreeconductorpowercablesuppliedwiththis instrumentisterminatedin apolarizedthreeprong maleconnectorrecommendedbytheNationalElec- tricalManufacturersAssociation.Thethirdcontact isanoffsetroundpinaddedtoastandardtwo-blade acplugwhichgroundstheinstrumentchassiswhen usedwiththeappropriatereceptacle.Tousethis NEMAplug in astandardtwo contact outletanadapter willberequired.Thegroundconnectionemerges fromtheadapterasashortleadwhichshouldbe connectedtogroundfortheprotectionofoperating personnel. NOTE ThisModel650ATestOscillatorisshippedfrom thefactorywith thepowertransformerdualprimary windings connected inparallelfor115 voltoperation. Ifoperationfroma 230voltsourceisdesired,pri- marywindingsmustbereconnectedinseriesas showninthedetailontheschematicdiagram. Asimultaneousfusechangewillalsoberequired. Sect.IIPage2 2.2OPERATION TheoperationprocedurefortheModel 650ATest Oscillatorisasfollows: a.Connectinstrumenttopowersourceof 115 volt, 50-1000cpsunlessmodifiedfor230voltoperation. b.Turninstrumenton and,forbestresults,allow aminimumwarm-uptimeof 15minutes. c.Selectdesiredoutputfrequencybyadjustingthe RangeSwitch and FREQUENCYcontrols. d.Connectloadtooutputterminalsandadjustfor desiredoutputlevelbysettingattenuatorswitch andAMPLITUDEcontrols. Refertothefollowingparagraphsforspecificin- structionsonsettingtoafrequency,loading,and useoftheoutputmonitor. SETTINGTOFREQUENCY Thefrequencyof atestsignalfromthe650Aiscon- trolledbythe FREQUENCYdialsettingand thesetting oftheFrequencyRangeSwitch. TheFREQUENCYdialiscalibratedfrom. 9through 10.Thisdialreadingmultipliedbythesettingof theFrequencyRangeSwitchwillgivethefrequency oftheoutputsignal. LOADING AND USEOFINTERNALVOLTMETER Theinternalvacuum tubevoltmeter(VTVM)measures theinputvoltagetoanoutputattenuatorsystem. ThisoutputattenuatoristheR. M. S.VOLTS/DB switchnexttothe600noutputterminalsinthe lowerrightcornerofthefrontpanel.TheVTVM hastwovoltagescalescalibratedato1.aand ato3plusadbscalecalibrated-12to+2dbm (0dbm=1milliwattinto600ohms).Whenusing thedbscales,therelativeoutputsignallevelis determinedindbbyalgebraicallyaddingthedb settingoftheattenuatorswitchtothedbreading oftheVTVM. NOTE CalibrationoftheVTVMsectionisbasedupona 600ohmresistiveloadbeingconnectedtothein- strumentoutputterminals.Theoutputdividercable supplied withinstrumentcontainsa load ofthisvalue. Loadsofothervaluesarethenconnectedtoeither setofterminalsontheoutputdividercable. Whenusingthevoltagescale,theattenuatorsetting determinesthescaletouseandalsoindicatesvoltage atoutputterminalswhen a fullscalevoltmeterindi- cationisobtainedwitha600ohmload.IfVTVM indicationislessthanfullscale,terminalvoltage canbedeterminedfromthemeterindicationwith thedecimalpointrelocatedtoagreewiththefull scalevalue.Thisvoltage,asindicatedbytheVTVM readingandtheattenuatorsetting,willbereferred toastheindicatedvoltageinthediscussion thatfollows. SPECIALCONSIDERATIONWITH+10/3.a ATTENUATORSETTING WhentheR.M. S.VOLTS/DBswitchisrotated fullclockwise(+10/3.aposition),astraight- throughconnectionismadeintheattenuatorto effectivelydisconnectitfromtheoutputsystem. Theactualoutputvoltagewillbethesameasthe indicatedvoltageasreadontheato3voltscale. Anyvalueloadcanbeconnectedtotheoutputtermi- nalsand the VTVM will indicateactualoutputvoltage. CONNECTINGA600OHMLOAD Aresistiveloadof600ohmsmaybeconnected directlytotheinstrumentoutputterminals.Under theseconditions,theindicatedvoltagewillbethe voltageattheoutputterminals. Athigherfrequencies,testleadsmustbeshortand theshuntingcapacitancelow.Atfrequenciesabove approximately 2 me,iftheexternalshuntcapacitance ishigh,useofthe6nVOLTAGE X. 01terminals oftheOutputDividerCableisrecommended. OUTPUTDIVIDERCABLE TheOutputDividerCablecontainstworesistors connectedinseriestoprovidealoadof 600ohms asshowninFigure2-1.Thefirstresistor(594 ohms)ismountedintheconnectorfortheinstru- mentoutputterminals.Thesecondresistor(6ohms) ismountedattheoutput end ofthecable.Thesetwo resistorvaluesprovidea 100to1(-40db)division ratioandasourceimpedanceof 6ohmsattheout- putendofthecable. a.600nLOADTerminals- Theterminalsmarked600nLOADatthe inputendoftheoutputcableareinparallelwith theinstrument600noutputterminals.With attenuatorin+10/3.0position,outputvoltageat 600nLOADterminalswillbethesameasthe indicatedvoltage. Internalimpedanceis300ohmswithoutputdivider cableconnected.Thevoltageavailableatthe600n LOADterminalswilldependuponthevalueofthe appliedresistiveload. Theactualvoltage(Ea)availableatthe600n LOADterminalswith aresistiveload(Rinohms) canbecalculatedfromtheindicatedvoltage(Ei) asfollows: b.6nVOLTAGEX.01Terminals- Theseoutputterminalsarerecommended Sect.IIPage3 whenevertheloadhashighdistributedcapacityor alowvalue.Loadsfrom6ohmsandupmaybe connectedhere. Theactualvoltageavailablefromtheseterminals is1/100oftheindicatedvoltageprovidedtheload resistanceisveryhighwithrespectto6ohms. Theactualvoltage(Ea)availableatthe6nVOLT- AGEX.01terminalswitharesistiveload(Rin ohms)canbecalculatedfromtheindicatedvoltage (Ei)asfollows: Iftheloadresistanceis6ohms,theactualvoltage willbe1/200oftheindicatedvoltage. J TO 650A OUTPUT G ,-, 594n L_ 300.fl.SOURCE IMPEDANCE ,-, I I I 50-5-15 ) Figure2-1.SchematicDiagramofOutputDividerCable Sect.IIIPage0 r I I . r I . I . I I I I I I 100KC-IOMC -+- BUFFER . AVCOUTPUT OSCILLATOR AMPLIFIER . AMPLIFIERMONITOR VI, V2,V3 V4V5 VI6,MI I r I L_-=-t.- l .4 i . . - VI718ALLASTl VII,VI2 I CONTROL V13,VI4,VI5 . SELECTOR , J 1-!- I I I I I I I I 80-5-27 Figure3-1.BlockDiagramofModel650ATestOscillator 3-1INTRODUCTION TheModel650ATestOscillatorcircuitrycanbe divided intoseveralbasiccircuitsasshown inFigure 3-1.Adiscussionofthesebasiccircuitswillbe foundinthefollowingparagraphs: 3-2 3-3 3-4 3-5 3-6 3-7 3-8 Oscillators BufferAmplifier AVCAmplifier OutputAmplifier OutputMonitor Output Attenuator PowerSupply Sect.IIIPage1 SECTIONIII CIRCUITDESCRIPTION forthispurpose.The10wattincandescentlamp (R80)hasapositivetemperaturecoefficientand ispartofthenegativefeedbackloop.Thislamp regulatestheamountofnegativefeedbackinac- cordancewiththeamplitudeofoscillationtomain- tainaconstantoutputlevelwithminimumdistortion overthe lowfrequencyoscillatorrange. Theoscillatorisadjustedforoptimumperformance byadjustmentofresistorR46 inthenegativefeed- backloop.ResistorR53isusedtosetthe lowfre- quencyoscillatorinput signal level to theAMPLITUDE controlequaltothesignallevelfromthehighfre- quencyoscillator.Theprocedureforadjustment ofthesecontrolswillbe found intheMAINTENANCE sectionofthismanual. ) ) 3-2OSCILLATORS Twooscillatorsareused tocoverthe frequencyrange from10cpsto10mc.Thelowfrequencyoscillator coversfrom10cpsto100 kcinfourrangeswhile thehighfrequencyoscillatorcoversfrom100kc to10mcintworanges. Eachoscillatorsectionisseparateandcomplete. TheFrequencyRange Switchallowsonly oneoscil- latortofunctionatatimebyautomaticallyswitching B+tothedesiredoscillatorsection.Itisrecom- mendedthatiftheinstrumentistobe onforlong periodsoftimewhen not inactualuse,thattheFre- quency Range Switch beleftin one of thefourlower rangessothatthehighfrequencyoscillatorwill notbeoperating. LOWFREQUENCYOSCll.LATOR Thelowfrequencyoscillatorisusedtocoverfre- quenciesfrom10cpsto100 kc andconsistsoftubes VllandV12.Thesetwotubesareconnectedas atwo-stageamplifierinwhichapositivefeedback loop in conjunction withanr-cnetworkcontrolsthe frequencyofoscillation. Thetubesmustbeoperatedoverthelinearportion oftheircharacteristicsinordertoprovideasine wave output.Anegativefeedbackloopisnecessary REFERENCES Bauer,B.DesignNotes on theResistanceCapacity OscillatorCircuit,Hewlett-PackardJournal. November-December,1949. Terman,F.E.RadioEngineersHandbook, McGraw HillBookCo.,NewYork,1943.Pages504-506. Edson,W.A. Vacuum TubeOscillators,JohnWiley w:,.,/ .l.fiSal _1k_- VII VI6 -r.W V4I.J.J;JP:,1.rtf.U1. .-<.I,I, 0.,.0.,.0 CIl Cll () ; I I u:!:2J I i) _.-lODe ,.+IO _.J L7 OH .0 0.0 .CKASStS I0IMEGOHM II(1000OHMS CONDITIONSOFDCVOLTAGEMEASUREMENT LLINEVOLTAGEAT1IS1230VO