HP-300A-Manual 电路图.pdf

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1、 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 t OPERATINGMANUAL PLUS SERVICEMANUAL MODEL300A HARMONICWAVE ANALYZER ThisisacombinedOp

2、eration,Instruction,andService ManualforallMode1300AHarmonicWaveAnalyzers. Thismanualcontainscompleteoperationandservicing instructionsforthe300Aandmaybeusedinplaceof thlInstructionandOperatingManualoriginallysupplied witheachinstrument. Copyright1956byHewlett-PackardCompany Theinformationcontainedi

3、nthisbooklet isintendedfortheoperationandmain- tenanceofHewlett-Packardequipmentand isnottobeusedotherwiseorreproduced withoutthewrittenconsentoftheHewlett- PackardCompany. HEWLETT-PACKARDCOMPANY PAGEMILLROAD,PALOALTO,CALIFORNIA,U.S.A. RadioFans.CN 收音机爱 好者资料库 II MODEL300AHARMONICWAVEANALYZER INSTRUC

4、TION todeterminetheharmoniccomponentsinacmachineryandpowersystems;to thestudyofinducedvoltagesontelephonelines;andtomeasurementofhum componentsinrectifiercircuits. Otherusesincludethestudyofnoisebyintegratingportionsofthespectrum withtheselectivitycontroladjustedforawidepassbandandthecheckingof wave

5、filtercharacteristicswithmaximumselectivity. TheModel300Aisalsousefulasadevicetomeasuretheamountofcrossor intermodulationproductsgeneratedbythesimultaneoustransmissionoftwo frequenciesbyanaudiosystemortomeasuredemodulationofamodulated waveappliedthroughanaudiosystem. 1-2SPECIFICATIONS Completespecif

6、icationsforthecEiJModel300AHarmonicWaveAnalyzerwill befoundonpage3ofthecEiJNo.300A-2ServiceManual. SECTIONII OPERATINGINSTRUCTIONS 2-1230VOLTOPERATION Thisinstrumentisshippedfromthefactorywiththepowertransformerpri- mariesconnectedinparallelforoperationfrom115volts.Ifoperationfroma powerlineof230vol

7、tsisdesired,thepowertransformerprimariesmustbe connectedinseriesasshownbytheTransformerDetailontheschematic diagraminFig.3onpage39oftheNo.300A-2ServiceManual. Someolderinstrumentshaveapowertransformerwithasingleprimarywind- ingforoperationfrom115voltsonly. The1.25ampereslo-blofuserequiredfor115volto

8、perationmustbereplaced bya0.6ampereslo-blofuseafterchangingprimaryconnectionsfromparallel toseriesforoperationfrom230vo.lts. IV 2-2CONTROLSANDTERMINALS Allcontrolsandterminalsarefullydescribedonpages4and5ofther5j:; No.300A-2ServiceManuaL CAUTION THISINSTRUMENTISACCURATEATAMBIENTTEMPERATURESOF APPROX

9、IMATELY55TO95DEGREESFAHRENHEIT.OTHERAMBI- ENTTEMPERATURESMAYNECESSITATEREALIGNMENTOFTHE SELECTIVEAMPLIFIERSYSTEM. 2-3OPERATION TheoperationoftheModel300Aisdividedintotwoparts.thecalibration adjustmentprocedureandthemeasurementprocedure. 2-4CALIBRATIONADJUSTMENTPROCEDURE Thisprocedurewillbefoundunder

10、theheadingofCALIBRATIONPROCE- DUREstartingonpage11ofther5j:;No.300A-2ServiceManual. Seetheimportantoperatingprecautionsgiveninstep26ofCALIBRATION PROCEDUREintheNo.300A-2manual. 2-5MEASUREMENTPROCEDURE Theinstrumentmustbecalibratedbeforeattemptingameasurement.Inthe followingprocedure,thevoltagebeinga

11、nalyzedhasafundamentalfrequency of80cpsandanamplitudeof20volts.Thefrequencyandamplitudeofthis hypotheticalvoltagehavebeenassumedtosimplifytheinstructions.Any voltagebetween1millivoltand500voltsatanyfrequencybetween30to 16,000cpscouldbesimilarlymeasured.Aharmonicfrequencymustnotbe higherthan16.000cps

12、iftheparticularharmonicvoltageistobemeasured. a.Calibratethe300Aaspreviouslydescribed. b.SettheMETERMULTIPLIERcontrolto50(XIOO)andtheSETTO100 FORVOLTAGEMEASUREMENTcontrolto100. c.SettheHALFBANDWIDTHcontrolto30.Seestep26Bonpage12of No.300A-2ServiceManualregardingthedegreeofselectivityneces- saryforme

13、asuringvoltagesofvariousfrequencies. d.Setthefrequencydialto80cpsandpeakthemeterindicationbyadjust- ingtheFINETUNINGcontrol.TheMETERSENSITIVITYcontrolshould beadjustedtogiveareadableindicationonthemillivoltmeter.Thein- strumentisnowtunedtomeasuretheamplitudeofthefundamentalfre- quency(80cps)withtheh

14、armonicsexcluded. e.Theactualvalueofthefundamentalvoltageisfoundbymultiplyingthe millivoltmeterindicationbythemultiplyingfactorshownbytheposition oftheMETERMULTIPLIERcontrol. J Example: METERSE.SITIVITYat500(5.aonmeterscale)fullscalemillivolts. Meterpointerat2.athereforemeteractuallyindicates200mill

15、ivolts. 200millivoltsx100(metermultiplierfactor)isequalto20,000millivolts or20volts. 2-5MEASUREMENTPROCEDURE(Contld.)v . .Turnthefrequencydialto160cps(secondharmonicof80cps)andsetthe METERSElSITIVITYandMETERMULTIPLIERcontrolstoobtainaread- ablemeterindication.UsetheFINETUNINGcontroltopeakthemeter in

16、dication.Themeterindicationtimesthemetermultiplyingfactorwill givetheamplitudeofthesecondharmonic. g.Repeatstepf.atasmanyhigherharmonicsasdesireduntiltheharmonic voltagesbecometoosmalltomeasure.Insomecases,theharmonicfre- quencywillbehigherthan16,000cpswhichwillbeoutsidetherangeofthe 300A. 2-6MEASUR

17、EMENTPRECAUTIONS Theresultsobtainedwiththe300Awilldependuponhowcloslytheoperator followsa fewsimplebutveryimportantoperatingprecautions.Thesepre- cautionsaregiveninstep26ofPROCEDUREFORCALIBRATIONonpage12 of1$o.300.1-2ServiceManual. Inaddition,a20KCfiltershouldbeusedbetweenthevoltagetobemeasured andt

18、heinputterminalsoftheModel300Awhenvoltagesatfrequenciesof5KC or10KCarebeingmeasured.Thisfilterwillpreventthefourthharmonicof the5KCvolt3.georthesecondharmonicofthe10KCvoltagefromentering the20KCseJ.ectiveamplifierandcausingerroneousmeasurments. 2-7SELECTIVITY Whenoperati.ngtheModel300A,itshouldbebor

19、neinmindthattheinstrument isafrequencyselective,widerangevoltmeterwhoseselectivityisvariable. Itisnecessaryduringoperationtodeterminethedegreeofselectivitydesired andtoadjusttheinstrumentcorrectlytoobtainthatdegreeofselectivity. Determinationoftheproperselectivitytouseinaparticularmeasurement should

20、primarilybebasedonthefactthatunwantedvoltagesmustbeattenu- atedbytheselectivityoftheinstrumenttolessthanonethirdofthevoltage undermeasurement.Thisattenuationis,inturn,dependentupontheorder ofseparationofunwantedvoltagesfromthedesiredvoltage,andtherelative magnitudesofthevariousvoltagesinvolved. Inst

21、rumentselectivityiscontrolledbytheHALFBANDWIDTHcontrolwhich iscalibratedfrom30to145.Thesecalibrationsindicatethefrequency separationfrmthecenterfrequencyatwhichtheselectivitycharacteristics oftheinstrumentattenuatesby40db(99%). AnotherwayofsayingthesamethingisthattheHALFBANDWIDTHcalibra- tionsindica

22、tetheminimumfrequencyseparationfroma100%voltagewhich willpermitaccuratemeasurementofa3%voltage. Itwilloftenbefoundconvenienttouseonlytwodegreesofselectivityasob- tainedbysettingtheHALFBANDWIDTHcontrolat145forminimum VI 2-7SELECTIVITY(Contld.) selectivityorat30formaximumselectivity.Usemlmmumselectivi

23、ty forvoltageswithafundamentalfrequencyhigherthan100to300cps.Use maximumselectivityforvoltageswithafundamentalfrequencylowerthan 100to300cps.Thissystemeliminatesthenecessityofdeterminingwhether anintermediatedegreeofselectivityofferssufficientattenuationforthecase athand. Occasionally,however,itisde

24、sirabletousedegreesofselectivitywhichare intermediatebetweenminimumandmaximum.Anexamplefollowstoillus- trateatypicalcaseofselectivitydetermination. RefertoFig.2onpage38oftheNo.300A-2ServiceManualwhichshows theselectivitycharacteristicsofthe300AforthetwoextremesoftheHALF BANDWIDTHcontrol.Aconvenientg

25、raphforconvertingattenuationinterms ofdecibelstopercentageisgiveninFig.9onpage45oftheNo.300A-2 ServiceManuaL ThegraphsofFigs.2and9areusedtodeterminethesettingoftheHALF BANDWIDTHcontrolasillustratedinthefollowing: Assumethatitisdesiredtomeasuretheharmonicsofan80cpsfunda- mentalandthatharmonicswhichar

26、e0.50/0orhigherare,ofinterest. Unwantedvoltagesmustbeattenuatedtolessthan1/3ofthevoltageunder measurementandforthisparticularcaseitwouldbe1/3of1/20/0or1/6 of10/0.Inotherwords,whenmeasuringthesecondharmonic,thefunda- mentalmustbereducedto1/6of10/0ofitsvaluebythe300Aselectivity characteristics.Referri

27、ngtoFig.9,weseethat1/6of1%isequivalent toapproximately56decibels.Therefore,theHALFBANDWIDTHcon- trolmustbeadjustedsothattheinstrumentwillattenuateby56decibels forafrequencyseparationof80cps. RefertoFig.2andsketchinacurvesimilartothetwocurvesshown. Thenewcurveshouldpassthroughthe56dbpointat80cpsoffre

28、sonance. Notethepointwherethenewcurvepassesthe40dbline.Thispointhas anabscissaofabout50cyclesoffresonance.Therefore,theHALF BANDWIDTHcontrolshouldbesetat50toobtain56dbattenuationat 80cpsoffresonance. TheinstrumentmustthenbecalibratedusingaHALFBANDWIDTH settingof50insteadof30insteps20through23ofPROCE

29、DURE FORCALIBRATIONonpage12ofNo.300A-2ServiceManual.See step26Bonthesamepageforadditionalinformation. SECTIONIII CIRCUITDESCRIPTION 3-1GENERAL ThecircuitryoftherFeJModel300AHarmonicWaveAnalyzerisdiscussedon pages8,9,10,and11ofthe(/!j)No.300A-2ServiceManual. VII SECTIONIV MAINTENANCE 4-1CABINETREMOVA

30、L Toremovetheinstrumentfromthecabinetitisnecessarytounscrewthe eightlargePhillipsheadscrewsonhecontrolpanelandslidetheinstrument forwardoutofthecabinet. Insomeolderinstruments,itmaybenecessarytoremovethewireconnect- ingthebottomchassistothemetalplateinthebottomofthecabinet.This wirewillbefoundonther

31、earoftheinstrument. 4-2TUBEREPLACEMENT Refertopage7ofServiceManualNo.300A-2forcompleteinstructionson tubereplacements. 4-3LOCALOSCILLATORAMPLITUDEADJUSTMENT Thisadjustmentcanbemadeatanytimeasdirectedinstep2ofPRELIMI- NARYTESTSModel300AHarmonicWaveAnalyzers.This manualcontainscompleteoperationandserv

32、icingin- structionsforthe300Aandmaybeusedinplaceof theInstructionandOperatingManualoriginallysup- pliedwitheachinstrument Copyright1955byHewlett-PackardCompany Theinformationcontainedinthisbooklet isintendedfortheoperationandmain- tenanceofHewlett-Packardequipmentand isnottobeusedotherwiseorreproduc

33、ed withoutthewrittenconsentoftheHewlett- PackardCompany. HEWLETT-PACKARDCOMPANY 275PAGEMILLROAD,PALOALTO,CALIFORNIA,U.S.A. 300A002 ,. TypicalFrontViewof-hp-Model300AHarmonicWaveAnalyzer . . TABLEOFCONTENTS PAGE 37 38 39 40 41 42 43 44 45 46 47 48 49 51 51 50 . TABLEOFCONTENTS Thefrequencydialandinte

34、rnaltuningcapacitoraredrivenbythevernierknobinthecenterofthe dial.Thedialscaleiscalibratedfrom0to16KCintermsoftheinputsignalfrequency. METERSENSITIVITY- Thistappedvoltagedividercontrolstheamplitudeofthevoltagesuppliedtotheselectiveamplifier andthepositionoftheknobindicatesthefullscalevalue,inmillivo

35、lts,ofthemeterscaleinuse. MILLIVOLTSMETER- Thismeterindicatesthevoltagemeasuredbytheinstrument.Themeterhasthreescalecalibra- tions.Thescaleinuseandthescalemultiplicationfactorareindicatedbythepositionofthe METERSENSITIVITYFULLSCALEMILLIVOLTSandtheMETERMULTIPLIERMAX.INPUT VOLTAGEcontrols. FINETUNING-

36、 Thisvariablecapacitorprovidesanincrementaladjustmentforthefrequencydial.Theinstru- mentiscalibratedwiththiscontrolrotatedsothatthemarkontheknobskirtisstraightupover thecenterofthecontrol. ON-OFFSWITCH- Thistoggleswitchcontrolsthepowersuppliedtotheinstrumentfromthepowerline.Whenthe instrumentisturne

37、don,theindicatorlampbelowthetoggleswitchwflllight. U) U) - o (1 - - - N o o o o (1 5. CONTROLS;ibleinthe300Awithno changeinpinconnections.Voltagerating ofoutputelectrolyticcapacitorsmustnot beexceeded. CIRCUITDESCRIPTION GENERAL- . . The-hp-Mode1300AHarmonicWaveAnalyzerisafrequencyselectiveheterodyn

38、etypevoltmeter signedtomeasureindividualcomponentsofcomplexwaveforms.Fullscalemeterreadingscan beobtainedfrominputvoltagesvaryingbetween1millivoltand500volts.Instrumentselectivity canbevariedtomeasureeithercloselyorwidelyspacedharmonicsovertheaudiospectrum from30to16,000cps. Basically,thecircuitcons

39、istsofaphaseinverter,alocaloscillator,abalancedmixer,afour sectionselectiveamplifier,andavacuumtubevoltmeter.Inadditiontothesebasiccircuits,the Model300Aincludesinputandrangemultipliersaswellasaninternalcalibratingsystemforuse instandardizingoverallinstrumentgain.TheblockdiagramgiveninFig.1showsthef

40、unctionof theindividualcircuitsandcontrols. Theinstrumentisdividedintotwochassiswithacommonfrontpanel.Theupperchassiscon- tainstheselectiveamplifierandvacuumtubevoltmetersections.Theremalnlngcircuitsare locatedinthelowerchassis.Theschematicdiagramissimilarlydivided. INPUTlitPHASEINVERTERCIRCUITS- Th

41、einputterminalsinthelowerleftcorneroftheinstrumentpanelareconnectedtoMETER MULTIPLIERswitchSlOlwhichprovidesrangesofXl,XlO,XlOO,andXlOOO.Inaddition,each positionofthisswitchiscalibratedinthemaximuminputvoltagethatmaybeappliedwithout overloadingthecircuitsoftheinstrument.Erroneousreadingswillresultfr

42、omcircuitclipping whentheinputsignalishigherthanthesepanelmarkings. TheMETERMULTIPLIERswitchisfollowedbytheSETTO100controlwhichmustbesettothe 100positioninordertoobtainacorrectvoltmeterreadingwhenmeasuringtheactualvalueofthe inputvoltage. Switch5102(S)permitsconnectingtheinputofthe6SJ7phaseinvertert

43、ubeVIOltotheinput signalortotheinternalcalibrationcircuit. de- l.U 0 0 0 0 N -:- l.U 0 - U1 C11 . lI) lI) - o lI - . . N o o o o lI 9. CIRCUITDESCRIPTION(Contd.) INPUT METERSENSITIVITYat500;METERMULTIPLIERat.5;SETTO100at100; andconnecta400cps,1/2volt,externalsourcetotheinputterminals.Tuneinstru- men

44、tto400cpsandadjustcontrolGforafullscaleMILLIVOLTSmeterdeflection. GraduallyshifttheexternaloscillatorfrequencyandswitchtheMETERSENSITIVITY controlcounterclockwisetomaintainaMILLIVOLTSmeterreading. Themeterindicationshoulddropgradually.Whentheoscillatoris60cpsawayfrom 400cps,thegradualdropmayshowahes

45、itationorasmallrisewhichisanindication ofa60cpshumpintheresonancecurve. Theexternaloscillatormustbetunedonbothsidesof400cpsforthistest.Referto TROUBLESHOOTINGsectionofthismanualformethodsofeliminatingthishump. PlottheresonancecurveonthebroadsamplecurvegiveninFig.8.Theplottedcurve shouldfallwithinthe

46、twooutsidelinesofsamplecurve. Setinstrumentcontrolsandconnectexternalsignalsourceasinstep9Aexceptset HALFBANDWIDTHcontrolat145.PeakinstrumentforafullscaleMILLIVOLTS meterreadingat400cps. Setexternaloscillatorto420,460,520,545,and700cps.Recordmillivoltreading obtainedateachfrequency. Repeatthissamepr

47、ocessafterrecordingthereadingsobtainedbytuningtheexternal oscillatorto380,340,280,255,and100cps. Iftheplottedcurvesfalloutsidethesamplecurvelimits,itwillbenecessarytochange thevalueofanyoneorallfourresistorsR18,R34,R74,andR77acrossthetoroid coils.Increasingaresistorvaluewillsharpentheresonancecurves

48、inbothbroad(145) andsharp(30)HALFBANDWIDTHcontrolpositions.Adjustmentofthebroadcurve mustbecompletedbeforeattemptingadjustmentofthesharptuningcurve. B. 1.tl I.) - 0 rif - .,. - N 0 0 : 0 0 C. Theselectiveamplifiermustberealignedafterchanginganyofthesefourresistors. D.SetHALFBANDWIDTHcontrolto30(shar

49、p)andplotresonancecurve,usingthepro- ceduregiveninstep9Bexcepttakereadingsat10,20,30,40,50,60,and70cpsabove andbelow400cps.Particularattentionshouldbegiventothefrequenciesof340and 460cpstobesurethatahumpdoesnotappearasexplainedinstep9A. 18. TESTPROCEDURE(Contd.) FINALTEST-(Contd.) 9D.(Contd.) Iftheplottedcurvesfalloutsidethesamplecurvelimits,itwillbenecessarytochange thevalueofeitherorbothresistorsR75andR76inthefeedbackcircuitsofthetwo centerstages.Decreasingthevalueoftheseresistorswillsharpentheresonancecurve. Theselectiveamplifiermust