HP-400B-Manual-sn-8938 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 HEWLETTPACK.DC01P/NY SOthN,;stSalesDivision P.O.Box7166 -FLosJcod7.1881 DALLAS,rEX S7-

2、209 OPERATINGANDSERVICINGMANUAL FOR MODEL400B VACUUMTUBEVOLTMETER Serial8938andAbove Copyright1955byHewlett-PackardCompany Theinformationcontainedinthisbooklel isint.endedfortheoperationandmain- tenanceofHewlett-Packardequipmentand isnottobeusedotherwiseorreproduced without.thewritlenconsentoftheHew

3、tett- PackardCompany. HEWLETT-PACKARDCOMPANY 275PAGEMILLROAD,PALOALTO,CALIFORNIA,U.S.A 400BOOl-l RadioFans.CN 收音机爱 好者资料库 OPERATINGANDSEIVICIGMANUAL FOR MODEL400B VACUUMTUBEVOLTMETEP ERRATA Deleeb:ndlngpst.ir.sua.,yelowp!as-;:ccap,-hp-StockNo. M-58. Addbnd:lngP05Dred-hp-S.-ckNo.G-lOD.Mir.HP. Add:bnd:

4、.gp_bt.insula:D-hp-S,;.;ckNc.G-83FoMfr.HP Addbdgpos.ogr(ur.d -hp-Sf.ckNG-76J.M!. shr:=ngsrap, RadioFans.CN 收音机爱 好者资料库 . H V U) o ., INSTRUCTIONANDOPERATINGMANUAL FOR MODEL400B VACUUMTUBEVOLTMETER PRODUCTIONCHANGES Serial8938andabove: ChangeC7to2!-Lf,fixed,paperdielectric, 20%,400vdcw,-hp-StockNo.16-

5、81, Mfr.GudemanCo.#231E205 #400BOOI SPECIFICATIONS FiJMODEL400B VACUUMTUBEVOLTMETER ,- VOLTAGERANGES: FREQUENCYRANGE: ACCURACY: VoltsFullScale(RMS)- .03.1.3131030100300 DB- -30-20-100 +10+20 +30+40 +50 2to100,000cycles/sec. 30/0offullscaleindicationonallranges, from10cycles /sec.to100KC. l/2db3to10c

6、ycles/sec. ldb2to3cycles/sec. METERCALIBRATION: VOLTMETERSTABILITY: INPUTIMPEDANCE: OVERLOADCAPACITY: POWERSUPPLYRATIG: OVERALLDIMENSIONS: WEIGHT: MetercalibratedtoRMSvalueofasinewave. Linearvoltagescalesa-IVand0-3V. Voltagerangesrelatedby10dbsteps. ZeroLevel- 1milliwattinto600ohms. Linevoltagevaria

7、tionsfrom105to125 voltswillcauselessthan20/0variation inreadingonallfrequenciesbelow100KC. Approximately9megohmsat100cycles/sec. and4megohmsat100,000cycles/sec. Meterwillnotbedamagedbyoccasional overloadsof100timesnormal. Voltage-115volts Frequency-50-1000cycles Wattage-50watts CabinetMount-7-3/4wid

8、ex9-1/4highx 10-1/2deep. RackMount-19widex8-3/4highx 10-1/2Ideep. CabinetMount-;shipping27lbs. RackMount- 17I;shipping30lbs. o o b:l o o . I . 00 - tv o - Jl 0 (J) (b 1 . p.l . SectionI TABLEOFCONTENTS - o o tJj o o I 00 - N o - U1 0 . 11.II 1I;TrUCrIOS 2-1IISPE:CTIO Thisinstrwnenthasbeentloroughlyt

9、estedandinspectedbefore beingshippedandisreadyfOlusewhenrecdved. Aftertheinstrumentisunpacked,itshouldbecarefullyinspected fordarllagereceivedintransit.Ifanyshippingdamageisfound, followtheprocedureoutlinedintheClaimforDamageinShip- mentpageatthebackoftIlisinstructionbook. 2-2COlTROLSANDTERMI!ALS ON

10、 Thistogglesvitchcontrolsthepowersuppliedtotheinstrument fromthepowerline.WhentheswitchisintheONpositionthe redindicatorwillglo DB-RMSVOLTS Thisrotaryswitchconnectstheproprmultiplierresistorsinto theciruitforthedesiredvoltagerange.Thepositionofthe switchindicatesthemeterscaleandthefullscalevoltageof

11、the rangeinuse.ThesitchpositionalsoindicatestheDBlevel AhenthemeterpointerindiateszeroontheDBscale. INPUT Thetwobindingposts,locatedinthelowerlefthandcornerof thecontrolpanel,areconnectedtotheinputcircuitoftheinstru- ment.ThebindingpostmarkedGisonnectedtothechassis. OUTPUT Thetvobindingposts,located

12、inthelowerrighthandcornerof thecontrolpanel,areconnectedtotheoutputoftheamplifier. Thamplifierhasahighimpedanceoutputcircuit.Theoutput voltageavailableattheseterminalsisfrom17.5to24voltswith fulls(alemeterdeflection. -.CAUTION-. TheInaxiInumvoltageappliedtotheinputterminals oftheModel400BVauumTubeVo

13、ltlnetermustnot exed600volts,theSUlllofthdevoltaeandthe acpckvoltage.Highervoltagesvillbrakdown the-apacitorsintheinputsystemoftheinstrument. -3- . FUSE Thefuseholdcr,locatedonthebackofthchassis,containsa .6ampereslo-blocartridgefuse.Toreplacethefuse,unscrew thefuseholdercapandremovetheblownfuse.Ins

14、ertanewfuse ofthesametypeandreplacethefuseholdercap. PowerCable Thepowercableconsistsofthreeconductors.Twoofthese conductorscarrypowertotheipstrumentwhilethethirdcon- ductor(greenwire)isconnectedtotheinstrumentchassis. Thethirdwireprojectsfromthecablencartheplugendofthe cableandmaybeconnectedtoagrou

15、ndwhenitisdesirableto haveagroundedchassis. BELOW10CPS,ABOVE10CPS Thistoggleswitchisusedtoaddcapacityacrossthemeter whentheinstrumentisoperatedonfrequenciesbelow10cycles/ sec.Theaddedcapacity(2000)bypassestheverylowfre- quenciesaroundthemetersothatthemeterpointerwillnot vibrate. 2-3OPERATION Voltage

16、Measurements-Plugthepowercableintoa115volt powerlineandturnthetoggleswitchto0Allowtheinstrument aboutfiveminutestoreachastateofstableoperation.Sette DB-RMSVOLTSrangeswitchtothedesiredvoltagerangeand connecttheinputterminalstothevoltagebeingmeasured.The BELOW10CPS,ABOVE10CPSswitchshouldbesettoagree w

17、iththefrequencyofthevoltagebeingmeasured.Themeter scalemultiplyingfactor(DB-RMSVOLTSswitchpositiondivided bythefullscJ.levalueofthemeterscaleinuse)timesthemeter indicationequalsthevoltagebeingmeasured. Examples: A.100(DB-RMSVOLTSswitchposition)1(full scalevalueofmeterscaleinuse)=100(Meter scalemulti

18、plyingfactor). 100(meterscalemultiplyingfactor)x.83(meter scaleindication)a83volts(measuredvoltage). B.30(DB-RMSVOLTSswitchposition):3(full scalevalueofmeterscaleinuse)=l()(meter scalemultiplyingfactor). -1- ) il ) ) ) ) . I : 1 10(meterscalmultiplyingfactor)x2.3(meter scaleindication)23volts(measur

19、edvoltage). Wheneveritisnecessarytoviewthewaveshapeofthemeasured voltage,anoscilloscopemaybeconnectedtotheOUTPUTtermi- nalsoftheinstrument. Asaprecautioninmaintainingaccuracyofmeasurment,itmust bekeptinmindthattheinstrumentisanaveragereading-device. Althoughthecalibrationonthefaceoftheinstrumentisma

20、rked RMSVolts,thissimplymeansthatthemeterwillreadtherms valueofatruesinewave.Ifthewaveformofthevoltagebeing measuredcontainsappreciableharmonicvoltagesorotherspuri- ousvoltages,errorsinnleasurementwillbeencounteredofa magnitudeindicatedbythefollowingtable. EFFECTOFHARMONICSONMODEL400BVOLTAGEMEASUREM

21、ENTS TrueValueIndicated InputVoltageCharacteristicsRMSValuebyModel400B Fundamental-100100100 Fundamental+10%2ndharmonic100.5100 Fundamental+20%2ndharmonic102100-102 Fundamental+50%2ndharmonic112100-110 Fundamental+10%3rdharmonic100.596 -104 Fundamental+20%3rdharmonic10294- 108 Fundamental+50%3rdharm

22、onic112 90-116 DBMeasurement-Decibelmeasurementsaremadeinthesame wayasvoltagemeasurementsexceptthattheDBscaleisusedand theIneasurementsmustbemadeacross600ohms,ifthe1milli- wattacross600ohmsreferencelevelistobeused.Thediffer- tencebetweentwoormorevoltages,measuredindecibels,maybe readdirectlyfromtheM

23、odel400Bprovidedeachmeasurementis madeacrossthesamevalueofimpedance.Thedecibellevelbe- ingnleasuredisdeterminedbysumdifferenceofthemeterscale indicationandtherangeswitchindication.Theplusorminus signsbeforethemeterscalefigures,determinewhetherthemeter scaleindicationistobeaddedorsubtractedfromthedec

24、ibellevel shownbytherangeswitch. -5- Examples: C.Interpretingtherangeswit-hpositionandmeter scaleindicationforalevelof+12db.Measured across600ohmswithonemilliwattacross600 ohmsasthereferencelevel. +10db(DB-RMSVOLTSswitchposition)plus+2 db(dbmeterscaleindication):+12dbor +20db(DB-Rlv1SVOLTSswitchposi

25、tion)plus-8 db(dbmeterscaleindication):+12db. D.Interpretingtherangeswitchpositionandmeter scaleindicationforthedifferencebetweentwo voltages,measuredindecibels,acrossthesame valueofimpedance. Voltagesequal-37dband+12db. -30db(DB-RMSVOLTSswitchposition)plus-7db (dbmeterscaleindication)=-37db +10dbpl

26、us+2db(fromExampleC):(-)+ 12db 49db (totaldecibeldiffer- encebetweenthe twovoltages) CharacteristicsoftheAmplifierFunctionoftheModel400B- Theoutputcircuitoftheamplifier(OUTPUTterminals)isde- signedtoworkintoaloadof100,000ormoreohms. Atfullscalemeterindication,theoutputvoltagewillbeapproxi- mately17.

27、5to24voltsonanyrange.Theapproximategainbe- tweentheINPUTandOUTPUTterminals,withfullscalemeter indication,isshownbythefollowingtable. GainRange +56db.03Vfullscale +46db 1 V II +36db. 3 V +26dbl.0V II +16db3.0V +6db10.0V - 4db30.0V -14db100.0V .24db300.0V ZeroMeterIndication-Themeterpointermaynotcoinc

28、idewiththe zeroscalemarkwhentheinstrumentisturnedoff.Thisconditionis normal. -6- *c c tr c c I 0: . I-. c . 1.T 0 . . SECTIONIII THEORYOFOPERATION 3-1INTRODUCTORY Tl.ecircuitoftheModel400BVacuumTubeVoltmeterconsists opacathodefollowerinputstage,astablizedamplifier,arecti- fierandmetersection,andareg

29、ulatedpowersupply. Thevoltageappliedtotheinputterminalsispassedthrougha blockingcapacitortothegridofthe6J5cathode-followerinput stage.Thecathoderesistorisatappedprecisionwirewound resistorwhichservesasthevoltmetermultiplieronallbutthe twohighestranges.Onthehigherrangesahigh-resistancefre- quency-com

30、pensatedvoltagedividerisswitchedacrosstheinput terminalsandaheadofthegridofthefirsttube. Thecathodefollowerfeedsintoabroad-bandresistance-coupled amplifierusing6AC7tubes.Negativefeedbackisusedinthis amplifierinordertoobtainhighstabilityanduniformresponse overawidefrequencyrange,andtomaketheamplifier

31、more independentofvariationsintubecharacteristics. Fromtheamplifierthevoltageispassedtoafullwaverectifier usinga6H6duo-diodetube.Theindicatingmeterisconnected fromoneplatetotheoppositecathodeofthetubeandtherefore isactuatedbyaportionoftheplatecurrentofthetwodiodes. Directcurrentfortheplatesupplyofth

32、etubesintheinstrument isobtainedfromaconventionalfull-waverectifierfeedingintoa resistance-capacityfilter.Avoltage-regulatingcircuitacross theoutputoftherectifierkeepstheplatesupplyvoltageconstant overawiderangeoflinevoltages. -7- o o tp o o . I . 00 - N o - U1 0 MI Fig.l,TopViewofModel400B CoverRem

33、oved -8- SECTIONIV MAINTENANCE 4-1COVERANDBOTTOMPLATEREMOVAL Thecoverisremovedbyunscrewingthefourscrewswhichfas- tenthecovertothebackoftheinstrument,andslidingthecover awayfromthepanel. Thebottomplateisfastenedtotheinstrumentwithfourscrews, oneineachcorneroftheplate. 4-2TUBEREPLACEMENT Thereplacemen

34、toftubeswillhaveaslighteffectuponthecali- brationofthisinstrument.Nowandthen,whenreplacing6AC7 tubes,apermanentdeflectionofthemeterpointerwillbeob- servedwiththeinputterminalsshortedandwhenthenewtube hasheated.Thisconditionisusuallycausedbyacathode-heater leakageandthetubeshouldberejectedinfavorofan

35、other. Wnenreplacing6H6and/or6AC7tubes,itisdesirabletocheck thevoltageresponseofthenewtubeifthevoltmeterisbeing operatedfromanunregulatedlinevoltage.Thischeckcanbe madebyapplyingaconstantvoltagetotheinputterminalsand varyingthelinevoltage10voltsfrom115volts.Thevoltmeter readingshouldnotchangebymoret

36、han2%atfrequenciesbelow 100KC.Tryanothertubeifnecessary. 4-3CHECKINGCALIBRATION Probablythemostaccuratemethodwhichcanbeusedinthefield tocheckthecalibrationoftheModel400Bisatestusingacathode- rayoscilloscopeandafreshlycalibrateddynamometertypevolt- meter. AfterthenewtubehasheatedintheModel400B,applya

37、low-fre- quency(50-60cps)voltagesimultaneouslytoboththeModel400B andthedynamometertypevoltmeters.Readingsofthetwoin- strumentsshouldagreeclosely.Tryanothertubeifnecessary. Next,calibratethecathode-raytubeoftheoscilloscopebyapply- ingalow-frequencysinusoidalvoltagesimultaneouslytothedy- namometervolt

38、meterandtothevertical-deflectingelectrodesof -9- thec-rtube.Nohorizontalsweepvoltageshouldbeused.Direc- tionsforconnectingtothedeflectingelectrodesofthetubeare usuallygivenbythemanufactureroftheoscilloscope.Bymeas- uringthepeak-to-peakdeflectionofthec-rtubetracewitha graphscreenandbynotingthereading

39、ofthevoltmeter,thede- flectionvoltageofthec-rtubecanbequicklydetermined.Itis importantthatthevoltageusedtocalibratethec-rtubebeessen- tiallysinusoidalandfreefromharmonics. NowconnecttheModel400Binparallelwiththevertical-deflec- tingplatesofthec-rtubeandapplysinusoidalvoltagesoffre- quenciesupto100KC

40、tothecombinationofthetwoinstruments. ThevoltageshownbytheModel400Bshouldagreecloselywith thatindicatedbythemagnitudeofdeflectionofthec-rtubetrace. Ifsuchisnotthecase,tryanothertubeintheModel400Band repeattheprocess. Theaboveprocedurewillgiveareasonablecheckatallfrequen- cieswithintherangeoftheModel4

41、00B,althoughacheckcannot bemadeofsmallvoltages.Lowvoltagerangescanbechecked bystartingwithavoltagewithinoneoftherangescheckedonthe oscilloscopeandworkingdownward.Forexample,iftheaccu- racyandfrequencyresponseofthe100-voltrangeoftheModel 400Bhal,beencheckedontheoscilloscope,applya25-voltwave totheMod

42、el400Bandnotethereadingonthe100-voltrange. Thenswitchtothe30-voltrangeandnotethatthereadingiscor- rect.Byextendingthisprocedure,allrangesoftheinstrument canbechecked. Althoughtheabovemethodswillnotgiveprecisionresults,they willoftenprovehelpfulindeterminingwhetherornotoldtubes haveexceededtheirservi

43、celifeornewtubesaresatisfactoryto use. Beyondchangingtubes,itisnotrecommendedthatrepairor calibrationofthisinstrumentbeattemptedinthefield,because oftheelaborateequipmentrequired.Eitherthecfj)factoryor anytEj;authorizedfieldRepairStationwillrecalibratetheinstru- mentquicklyandatanominalcharge;contac

44、tyour1!jfieldengineer forfurtherin.formation.Useofthisservicewillusuallysavea greatdealoftime. -10- a o tJ:j a a l- I- o. SEE RBI SEEFIG.2 Fig.ZBottomViewofModel400BBottomPlateRemoved -11- o ,0 . . Id . 0 0 Id 0 0 . III ,j:. III 0 0 IX tp 0 a:l 0 .- 0 I 0 .- 00 - 0 N 0 0 :E- U1 0 ll Ul 00 1 . III .-

45、 00 v. 00 III P- ili cr 0 .J 00 rl)l99-H . :1. - I to- o - -12- , ClC2 #20,u.u20UJ,i. iNPU1 1 C3 RS 2200 8BELOwiOC P R2_ 6200 IOUTPuTI ) . Z, , 0 1 0 0 ,00 00 PS RREQUENCYVACUUMTUBEVOL SERIAL8938aABOVE: u TABLEOFREPLACEABLEPARTS Circuit Ref. Cl C2 C3 C4 C5,C6 C7 C8 C9abcd CIO Cll C12 C13 C14abcd C15

46、abcd C16abcd C17 Rl,R2 Description Capacitor:variable,ceramic, 5- 201llJ.f,500vdcw Capacitor:variable,ceramic, 5-20Illtf,500vdcw Capacitor:fixed,paper, .1lJ.f,lO%,600vdcw Capacitor:fixed,mica, 22!-LlJ.f,lO%,500vdcw Thesecircuitreferencesnotassigned Capacitor:fixed,paper,dielectric, 2Ilf,20%,400vdcw

47、Capacitor:fixed,electrolytic, 50!-Lf,-10%,+200%,50vdcw Capacitor:fixed,electrolytic, 20,20.40!-Lf,450vdcw Capacitor:fixed,paper, .1Ilf,10%,600vdcw Capacitor:fixed,electrolytic 10Ilf,450vdcw Capacitor:fixed,electrolytic, 2000Ilf,6vdcw Capacitor:fixed,mica, 22!-L!-Lf,lO%,500vdcw Capacitor:fixed,electr

48、olytic, 20,20,20,20lJ.f,450vdcw Capacitor:fixed,electrolytic, 50Ilf,-10%,+200%,50vdcw Resistor:fixed,composition, 8megohms,1%,1W -hp- StockNo. 13-20 13-20 1601 14-61 16-81 18-50 18-42S 16-1 18-10 18-6 14-61 18-42 18-50 31-8M Mfr.intio +-.-.:c._._._. R6 R7 R8 R9 Resistor:PartofRangeSwithsy. Resistor:

49、i.-xed,composition, 1.1megohms,-0%+1%,1 W Resistor:fixd,composition, 2200ohms,+10%,1/2W Thiscircuitreferencenotassigned 31-1.04M 2.3-2200 HP B F.B2221 RIO Rll R12 R13 R14 Resistor:fixed,composition,24-82K 82,000ohms,ilO%,1W Resistor:fixed,composition,23-180K 180,000ohms,10%,1/2W Electricalvalueadjustedatfatory Resistor:fixed,wirewound,4B-90 11.16ohms Resistor:variable,wirewound,210-28 100ohms,line