HP-201B-Manual-sn-768 电路图.pdf

HP Archive This vintage Hewlett Packard document was preserved and distributed by www. Please visit us on the web ! On-line curator: Glenn Robb This document is for FREE distribution only! RadioFans.CN 收音机爱 好者资料库 INSTRUCTIONANDOPERATINGMANUAL FOR MODEL201B AUDIOOSCILLATOR Serial768andAbove HEWLETT-PACKARDCOMPANY 395PAGEMILLROAD,PALOALTO,CALIFORNIA,U.S.A. RadioFans.CN 收音机爱 好者资料库 INSTRUCTIONS MODEL201B AUDIOOSCILLATOR Speclficatons FrequencyRaing- FrequecyRange.20to20,000cycls/sec. FrequencyDialCallbrahon-20to200 Range- xl20-200cycles/sec. xIa200l000cyc e s /sec. xl002000-20,000cles/sec. CalibratIonAccuracy-2%(1%Wlhstandardizahon) FreqencyResponse-1db20to20,000cycles/sec.Reference: 1000cycles/sec.,425volts,600ohmsresIstiveload. FrequencyStablllty-2%undernormaltemperatureconditions, includIngImtialwarmup.LinevoltagevariatIonsfrom105to 125voltswillcauseanegllg1blechangeinfrequency. PowerOutputRating- Hum-Lessthan.1%ofratedoutput.Lessthan.1%atanysignalbelow 3wattswheateuatorisused. LoadImpedanc-600ohms,reslstve Approx.matedIternalImpedance-75ohmsbelow5000cycles/sec. atzerosettIngofatenuator.600ohmsoverentirefrequencyrange wththeattenuatorstat10dbormore. %DIStorlon 1 1/2 1 o ., PowerOuput3wattsntoratedload(42.5 Dlstorhon- Watts0tput 3 1 1 voltsacrossa600ohmload) FrequencyRange 50to20,000cycles/sec. 50to20,000cycles/sec. 20to20,000cycles/sec. p:j . o N PowerSupplyRatmg- Voltage-115volts Frequecy-50/60cycles Watage-,105watts -1 RadioFans.CN 收音机爱 好者资料库 OverallDimensions- CabinetModel-18-3/4widex8-5/8highx11-3/4dep RackModel-19widex8-3/4hlghx11-3/4deep Panel-19widex8-3/4hIgh Depthbehindpanel-10-1/2 Weight- CabinetModel-29pounds RackModel-29pounds OperatingInstructions Inspection- Thisinstrumenthasbeenthoroughlytestedandinspectedbeforebeing shippedandisreadyforusewhenreceived. Aftertheinstrumentisunpacked,theinstrumentshouldbecarefully inspectedfordamagereceivedintransit.IfanyshIppingdamageisfound, followtheprocedureoutlinedintheClaimforDamageinShipmentpageat thebackofthISinstructionbook. ControlsandTerminals- OFF-ON-Thisrotaryswitch.WhIChislocatedinthelowerleftcorner ofthecontrolpanel,controlsthepowersuppliedtotheinstrumentfromthepower hne. FREQ.RANGE-Thisrotaryswitchinsertsvariousvaluesofresistance inthefrequencydeterminingcircuitoftheoscillator.Thepositionofthisswitch indicatesthemultiplyingfactorforthefrequencydialcallbration. FrequencyDial-Thisdial,locatedinthemIddleofthecontrolpanel, iscalibrateddirectlyincyclespersecondforthelowestfrequecyrangeofthe oscillator.Thedialandtuningcapacitoraredrivenbytheknobjustbelowthe dialescutcheon. AMPLITUDE-Thisvariableresistorcontrolstheamplitudeoftheos- cillatorvoltageadmittedtotheamplifierandthereforetheoutputvoltageofthe instrument.ThiscontrolIScal1bratedfrom0to100inarbitraryunits. ATTENUATION-TheTilpadtypeattenuatorisusedtoreducetheout- putoftheosciIlatortoanydesiredlevelwithoutchangingtheratiobetweenthe humvoltageandsinewavevoltage.Theattenuatoriscontinuouslyvariable with.thecalibrationmarkseveryfiveandtendbfrom0to40db. -2- N o .- OJ . o o ., . o N FUSE-Thefuseholder,locatedonthebackofthechassis,contamsa 1.5amperecartridgefuse.Thefusemaybereplacedbyunscrewingthefuse- holdercapandInsertinganewfuse.For230VoperatIousea.75amperefuse. PowerCable-ThepowercableconsIstsofthreeconductors.Twoof theseconductorscarrypowertotheinstrumentwhIlethethudcoductor (greenwire)isconnectedtotheinstrumentchassIs.Thethirdwireprojects fromthecableneartheplugendofthecableandmaybeconnectedtoaground whenItISdesirabletohaveagroundedchassis. OutputTermInals-Thetwobidingposts,InthelowerrIghtcornerofthe controlpanel,aretheoutputterminalsfortheOSCIllator.ThebldLgpost markedGisconnectedtothechassisoftheinstrumentaswellastotheoutput transformer. Operation- TheprocedureforoperatmgtheModel201BAudioOSCIllatorISasfollows: 1.Connecttheinstrumentpowercableboa115Vpowerlineandtheout- putterminalstotheequipmentbemgtested. 2.TurnthepowerSW1tchtoONandallowaboutfveminutes(thirty minutesormoreforextremeaccuracy)forthe1nstrumenttoreachoperating temperature.SettheFREQ.RANGEcontrolandthefrequencydialsothattheir ind1cahonswhenmultipliedtogether,equalthedesiredfrequency.Forexample: RANGEcontrolsetatIXlOOtimesthefrequencydialsettmgof20-2000 cycles/sec. 3.SettheATTENUATORcontroltozeroandtheAMPLITUDEcontrol forthedesiredoutputvoltage.Aftertheoutputvoltagehasbeesetw1ththe AMPLITUDEcontrol,theATTENUATORcontrolmaybeusedtoreducethe outputvoltagetoanydeSiredvalue. TheModel201Bshouldbeoperatedwithitsratedloadforbestresults. Theattenuatoriscal1bratedfora600ohmsload.Theosc1llatormaybeoperated wIthloadsotherthan600ohmswithoutdamagetothelOSrument.Anyloadof lessthan600ohmswillcausean1ncreaseindistortionwhileloadsofgreater than600ohmswillresultinlesspoweroutput. Toavo1dexcessivehumvoltagesatlowoutputlevels,theAMPLITUDE controlshouldbesetsothattheoscillatordeliversratedoutputwithzeroatten- uation.ThentheATTENUATORcotrolissetsothatthedeSiredoutputlevel 1S-obtained. -3- CircuitDescription ThecircuitoftheModel20lBconsistsofanoscillatorsection,anampli- fiersection,andaregulatedpowersupply. TheoscillatorsectionincludesVIandV2,andisbasicallyatwo-stage resistance-coupledamplifieroverwhichbothpositiveandnegativefeedbackare applied.Thepositivefeedbacknetworkisafrequency-selectiveresistance- capacitancecombinationwhichisusedtocontrolthefrequencyofoscillation. NegativefeedbackisusedtostabilizetheoperationofthecircuIt.Themagni- tudeofthenegativefeedbackisdeterminedbyaresistancenetworkwhichcon- tainsanon-l1nearelementintheformofa3-wattincandescentlamp.Thisele- mentcontrolstheamountoffeedbackinaccordancewiththeamplitudeofoscIlla- tionandconsequentlymaintainstheproperoperatingpointforthesystem. Theamplifiersectionisaconventionalaudiopoweramplifierwithapush- pull.outputstage.Negativefeedbackisusedinthiscircuittominimizedistor- tionandtoprovideauniformfrequencyresponseovertheentirerangeofthein- strument.Theamplifieroutputtransformerfeedsa600-ohmT-padattenuator, WhIChhasarangefromzerotoinfinity;practically,however,theattenuatoris usableto40db. Thepowersupplyincludesaconventionalfull-waverectifierandavoltage- regulatingcircuit. Maintenance o - tl:l , CoverandBottomPlateRemoval- Thecoverisremovedbyunscrewingtheeightscrewswhichfastenthe covertothetopandbackoftheinstrument. Thebottomplateisremovedbyunscrewingthefourscrews,oneineach cornerofthebottomplate,whIchfastentheplatetothechassis. TubeReplacement- Whenreplacinganyofthetubesexceptthepowerrectifier.ItISdesir- abletomeasurethedistortionintheoutputifmaximumperformanceofthein- strumentisdesired,becauseapoortubecancauseexcessivedistortionwith- outseeminglyaffectingtheoperation. Distortion- ExceSSIvedIstortionintheoutputvoltageoftheoscillatormaybecaused byleakingcoupl1ngcapacitor,defectivetubes,oropenby-passcapacitors. -4- C1 _. 00 <T o FrequencyStandarmzation- Thefrequencycalibratioofoneorallrangesmaybecheckedagainsta frequencystandardbymeansofanoscilloscope.Theprocedureisasfollows: 1.Allowtheoscillatortowarmupfor30minutes.Connecttheosclllator outputtotheverticalplatesofanoSClIoscopeandthefrequencystandardtothe horizontalplates. 2.Setthefrequencydialandadjusttheoscillatorfrequencyadjustments asshowninthefollowlngtable. Range xl xlO xlOO FrequencyDialSetting 100 100 100 AdjustmentControl R7 R8SeeFigure2 R9 o ., I!l . o N TheproperLissajousfigureontheoscilloscopewlllindicatewhenthe oscillatorlSadjustedtothesamefrequencyasthestandard.Thevanablere- sistorsforfrequencyadjustmenthaveshaftsslottedtofitascrewdriver.These adjustmentsarereachedthroughaccessholesinthebottomplate.Therange adjustedbyeachcontrollSstampednexttothevanablereslstor. LubricabonofTuningCapacltorDriveAssembly- Thetumngcapacitordriveassemblyshouldbe011edonceamonthlfthe instrumentisinconstantuse,otherwiseonceeverysixmonths. Thevernierdnveshaftbearingshouldhaveonedropof011putoneach endofthebearing. Theidlerpulleyshouldhaveadropof011andthespnngloadedtake-up pulleyshouldhaveadropof011ateachendofthepulley. AsabsfactorylubncantforthetuningcapacitordriveisLubriplate#2, manufacturedbytheFlskeBrothersRefiningCo.,Newark,NewJersey. PowerTransformerPrlmaryConnecbons- TheModel201Bpowertrasformerisconnectedfor115voltsoperation whentheinstrumentleavesthefactory.RefertotheTrans.Detailonthe schematicdiagramforthecorrectconnectionsfor230voltoperation. -5- VoltageRegulatorCircuitAdjustrnent- Whenatbe(V6,V7orV8)hasbeenreplacedinthevoltageregulator circuit,thedirectcurrentvoltagebetweenthejunctionofR32,R35andthechassIs shouldbemeasured.Ut.hisvoltageisnot240volts,variableresistorR33should beadjustedtobnngtheregulatedvolagebackto240volts.Theregulatedvoltage shouldalsobecheckedtoseethatitremainsat240voltswhenthepowersupply voltageISvariedfz:om105to125volts.Utheregulatedvoltagedoesnothold constant,replacementofoneorallofthetubesInthevoltageregulatorcIrcuit wIllusuallybetheremedy. HumBalanceAdjustmentRS7 ThIsvanableresistorisusedtominimizethebeatbetweentheoscillator andthepowersupplyfrequency.Thisvanableresistor,whichislocatedas showninFig.2,ISadjustedforminImumbeatbetweentheoscl1latorandpower supplyfrequency.Theoscillatorshouldbetunedtothepowersuppyfrequency. OutputStageDistortionAdjustmentR42- Thisvanableresistor,whichislocatedasshowninFIg.2,isadjusted forminimumdistortionat30cycles/sec.Wheneitherorbothoftheoutputtubes (V4,V5)arereplaced,thISadjustmentshouldbechecked. ReplacementofLatnpRIO- The3-wattlampRIOisoperatedataverylowlevelandshouldhavean alrnostinfinitelife.Therefore,thelampshouldnotbechangedindiscriminately. However,shouldthelamprequIrechanging,ItISnecessarytochecktheac voltagefromthejunctionofR16andC7tothechassiswiththenewlampinthe circuit.Asmeasuredwithahigh-impedanceacvacuumtubevoltmeter,thIs voltageshouldbewithintherangeofapproxirnately18-22voltswhenthe Model201Bistunedto1000cps.Ifthevoltageisnotwithinthisrange.itmay becorrectedbyadjustmgR16. Ifthevoltagecannotbebroughtwithintherangefrom18-22watsby meansofR16,thenewlampshouldberejectedinfavorofanother. -6- N o -to . o TroubleShooting- ThefollowingisallstingofposslblesynlptOtnS,causesandretnedies. o ., o. ll ll . t:Q . o N Sytnptoms Instrutnentinoperative (Indicatorlatnpwontlight, noaudlooutput) Instrutnentinoperative (Indlcatorlatnplights, noaudiooutput) IntertnittentOutput Causes Blownfuse Defectivetube Checkthe5Y3GT tubefirst Shortcircuit10DC powercircuitcapa- citor(CIl,C13,ClO orCIIabc) CapacitorsC5,C7, C8orCIOinter- tnittentlyopen -7- Retnedles Clearshortcircuit andreplacefuse Replacetube(See, TubeReplacetnentin Maintenancesection) Replacecapacitor Replacecapacitor )W(;,.2 , -/tl/ /3/Sb 4/SQSc.,.:., To . CI4 R20 20 IA.TUDfI Rit R3.5.I 0. C1 IDIJF R.8 lOOO RI1 - ,#I. C6 .003 UF OSC.VOLTAGE 18TO22AT1000#1.0_I CYCLES,.-.,I V2 66 0 560K RIS 1000 Ril 56. .5UF RI 3000 RIIRI2 561(ICOK R6 41.IK TUNINGCAPACITOR C3 eSECTIONS 2ISECTION FREDRANGEI R 413K RO 41TM 00 . GEJ 01ON-OFF. V9 4J 5Y:!lGT 10IH ;l r OK R 40IJFlOOK Clle 10F II RO 00. V6 6Y6G va ,R150 V7 6511.7 ;.240 R3 VI 50K R32 33. ROl R33 2.210. RM 01 r o o o o R35 ./560K .:0/., jo; .0() / 1- .,., C C :0 fT1 GS-.SJ.L.F C8 -/,; /(. / I: I010r OJ. - OJ .,., C C :0 fT1 - -_. o R31 33K C10 INSTRUCTIONSFORRECTIFIERTUBEREPLACEMENT Theseinstruf;:tionsapplytoanyHewlett-Packardinstrumentinwhicha 5V4tubeismountedinthepowerre,:tifiertubesocket.Whenitisnecessaryto replacetherectifiertube.a5Y3GTtubemaybeusedasareplacementifthe followinginstructionsarefollowed. INSTRUMENTSWITHDCVOLTAGEREGULATORCIRCUIT- The5V4tubemaybereplacedbya5Y3GTtubewithoutanycircuitchanges Afterthe5Y3GTtubehasbeeninstalled,theregulatedvoltageshouldbemeas- uredtoseeifitagreeswiththevoltageshownonheschematicwiringdiagram intheinstructionbook.Iftheregulatedvoltageisincorrect,itmaybecorrected byfollowingtheinstructionsintheinstructionbook. INSTRUMENTSWIlHOUTDCVOLTAGEREGULATORCIRCUIT- The5V4tubemaybereplacedbya5Y3GTtubeprovidingtheresistor,in serieswiththeDCoutputoftherectifier,isremoved.Thisresistordoesnot appearintheschematicwiringdiagramntheinstructionbook.Thefollowing instrumentsusea500ohmsseriesresistor:ModelslOOC,ZOOD,lOZD.ZlOA. 300BCD,andthe400A. TABLEOFREPLACEABLEPARTS Circuit-hp-Mfr.*.eetlallduurat:y 395PAGEMILLROADPALOALTO.CALIF. l