HP-411A-Manual 电路图.pdf

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1、HEWLEqPACKARDCOMPANY SERVICE 411A RFMILLIVOLTMETER , RadioFans.CN 收音机爱 好者资料库 011931 V!J-, OPERATINGANDSERVICEMANUAL MODEL411A SERIALSPREFIXED:131- RFMILLIVOLTMETER CopyrighlHEWLETT.PACKARDCOMPANY1962 1501PAGEMILLROAD,PALOALTO,CALIFORNIA,U.S.A. Printed:FEB1962 RadioFans.CN 收音机爱 好者资料库 Mode1411ATableof

2、 Contents ListsofIllustrationsandTables TABLEOFCONTENTS NumberTitlePageNumberTitle Page 1-1.Model 411A RFMillivoltmeter1-13-8.FrequencyResponse of 3-1.FrequencyResponse ofBNCOpenCapacitive Divider3-1 CircuitProbeTip .3-03-9.ElectricalZeroAdjustment 3-3 3-2.Input Impedance ofBNCOpen3-10.OperatingProc

3、edure 3-4 CircuitProbeTip.3-04-1.BlockDiagram. 4-1 3-3.FrequencyResponse of Type N5-1. SerVicing EtchedCircuitBoards5-4 IfTilProbeTip. . .3-05-2.CalibrationTestSetup 5-6 3-4.FrequencyResponse ofPen-Type5-3. Right Side Internal View5-6 ProbeTip. .3-05-4.TestSetup forFinalTest 5-7 3-5.Input Impedance

4、ofPen-TypeProbeTip.3-0 5-5.Left SideInternalView5-8 3-6.FrequencyResponse ofVHFProbeTip3-0 5-6.PowerSupply (Schematic Diagram)5-10 3-7.Input Impedance of VHFProbeTip3-1 5-7.Voltmeter(Schematic Diagram)5-11 LISTOFILLUSTRATIONS .Section IGENERAL INFORMATION 1-1.GeneralDescription 1-3.ProbeTipsAvailabl

5、e 1-6.InstrumentIdentification 1-8.PowerCable. -IIPREPARATION FOR USE . . . . . . 2-1.UnpackingCartridgeand/orCable Replacement 5-13.TubeReplacement. . . . . . . 5-16. Troubleshooting. . . . . . . . 5-19.MeasurePowerSupply Voltages 5-21.MeasureRipple. . . 5-24.DownscaleMeterCircuit. . 5-26.Modulator

6、/AmplifierTuning. 5-30.Modulator/AmplifierGain 5-31.UpscaleMeterCircuit 5-33.OutputCircuit. 5-34.Bias Adjustment. . . 5-35.Hum Balance. 5-36.ZeroControl. 5-37.Chopper Amplifier Gain 5-40. MaintenanceProcedures 5-41.TransistororTube Replacement . 5-43.Calibration. 5-45.FinalTest. VIREPLACEABLE PARTS

7、6-1.Introduction . . 6-4.OrderingInformation Page 4-2 4-2 4-2 4-2 5-1 5-1 5-1 5-2 5-2 5-2 5-2 5-2 5-3 5-3 5-3 5-5 5-5 5-5 5-5 5-5 5-5 5-5 5-5 5-5 5-5 5-7 6-1 6-1 6-1 t Ii. 01193-1 LISTOFTABLES NumberTitle 1-1.Specifications 5-1.RecommendedTestEquipment 5-2.Component Replacement 6-1.ReferenceDesignat

8、ion Index 6-2.ReplaceableParts Page 1-0 5-1 5-2 6-2 6-8 iii 110.-_ RadioFans.CN 收音机爱 好者资料库 Section I Table1-1 Model411A Table1-1.Specifications VOLTAGERANGE: 10 mvrmsfullscaleto 10 voltsrmsfullscale insevenranges.Fullscalereadingsof 0.01, 0.03, 0.3,1,3, and 10voltsrms. FREQUENCY RANGE: 500kcto1 gc w

9、ithaccessoryprobetips. ACCURACY: 500keto50mc,3%of fullscale;50mcto 150me,6%offullscale;150mcto1 gc, 1 db usingappropriateprobetips. PROBE KIT: 411A-21GAccessoryProbeKit.Thiskitin- cludesthe 411A-21B, 411A-21C, 411A-21D, 411A-21FProbeTipsand a 411A-21A-3 Replacement DiodeCartridge. TERMINATION: Model

10、 908A 50-ohmTermination,Type N male,swrlessthan 1.05fromdcto4000 mc. METER SCALES: Twolinearvoltagescales,0to1 and 0 to 3, calibratedin thermsvalue of asinewave. DBscale,calibratedfrom+3to-12db; 0 db= 1mwin 50ohms. PROBETIPFURNISHED: 411A- 21EBNCOpenCircuitProbeTip,500 kc to 500mc.Shunt capacity:Les

11、sthan 4 pf. Maximum input:200 vdc.Inputresistanceat 10 mc:typically80Kohms. INPUT RESISTANCE: Depends onprobetip, frequency and inputvoltage typically 200K ohmsat1mcand I voltrms. GALVANOMETER RECORDER OlTTPUT: Proportionaltometerdeflection.1 rna into 1000 ohmsatfullscaledeflection. POWER: 115or230v

12、olts1010,50 to 60cps,35watts. DIMENSIONS: Cabinet Mount:11-3/4in. high,7-1/2in. wide, 12in. deep Rack Mount: .-. . TOP :. :l ,. - j. I. -l rr=;-;J. -lr-i * j SIDE: :ru 0REAR ii 411A-31DTypeNTeeProbeTip, 1mcto 1 gc.SWRislessthan 1.15 whenterminated in 50ohms.Maximum input:10 vdc. ACCESSORIES AVAILABL

13、E: ProbeTips: 411A-21BPenTypeProbeTip,500 kc to 50mc.Shunt capacity:Lessthan 4 pf. Maximum input:200 vdc. Inputresistanceat 10mc:typically80Kohms. 411A-21C VHFProbeTip,500 kcto250mc. Shunt capacity:Lessthan2-1/2pf. Maximum input:200 vdc.Inputresistanceat10 me: typically80Kohms. 411A-21F100:1 Capacit

14、yDividerProbeTip, 500 kc to 250mc.Division Accuracy:1%; shunt capacity:2 pf.Maximum input:1000 volts pk (dc + pkac). WEIGHT: CabinetMount: RackMount: Net12lb, shipping18lb Net15Ib, shipping 28 Ib . 1-001193-1 Model41lASection I ParagraphsI-Ito1-10 SECTIONI GENERALINFORMATION 1-3.PROBE TIPSAVAILABLE.

15、 Seeparagraph3-3forinstructionsbefore attemptingtooperatethisinstrument. FrequencyRange 500kc -SOmc 500 kc-250mc 1mc- 1000mc 500 kc500mc 500 kc-250mc 1-5,Acompleteprobe-tipkitcontainingtheseprobe tipsplusanextra,replacement,cartridgeina handy caseisavailablefromHewlett-Packardasstock number411A-21G.

16、 I-10,Topreservetheprotectionfeaturewhenoper- atingtheinstrumentfromatwo-contactoutlet,usea three-prongtotwo-prongadapterandconnectthe greenpigtailontheadaptertoground, 1-9.Fortheprotectionofoperatingpersonnel,the NationalElectricalManufacturersAssociation (NEMA)recommendsthattheinstrumentpanel and

17、cabinetbegrounded,AllHewlett-Packardinstru mentsareequipped with athree-conductorpower cablewhich, when plugged into anappropriaterecep- tacle,groundstheinstrument,Theoffsetpin onthe powercablethree-prongconnectoristheground pin. 1-7.Hewlett-Packardusesatwo-sectioneight-digit serialnumber(000-00000)

18、.Ifthefirstthreedigits oftheserialnumberonyourinstrumentdo notagree withthoseonthetitlepageofthismanual,change sheetssuppliedwiththemanual willdefinedifferences betweenyourinstrumentandtheModel41lAdescribed inthismanual, 1.8.POWERCABLE. -6.INSTRUMENTINDENTlFICATlON. 1-4.ToincreasetheusefulnessoftheM

19、ode1411A, anumberofscrew-onprobetipsareavailableindi- viduallyasfollows: ProbeTip4!/JStock No. Clip-on411A-2IB VHF411A-2IC TypeN141lA-21D BNC(supplied)411A-2IE 100:1Divider411A-21F 1-1. GENERALDESCRIPTION. 1-2.TheHewlett-PackardModel 411ARFMillivolt- meterisasensitiveacvoltmeterwhich willmeasure acc

20、uratelyfrom0.01voltrmsto10voltsrmsfull scaleinthefrequencyrangeof500kc to 1000mc (1gc).The411Aprobewhenusedwithoutacces- sorieswillrespondtofrequenciesupto4 gcandmay beusedasanindicatoruptothisfrequency.The Model411Aissuppliedwith aBNC-typescrew-on probetipprovidingeasyandrapidmeasurementat lowfrequ

21、encies.Otherprobetips,whichmake possibleconvenientmeasurementat1000mc,are available.TheModel 411Ahasarecorderoutput with anadjustableleveL CAUTION FigureI-I.Mode1411ARFMillivoltmeter 01l93-11-1/1-2 SECTIONII PREPARATIONFORUSE Model411A 2-1.UNPACKING TYPICAL RELATIVE0 RESPONSE (OBI-I-+-+_-+_-i Figure

22、3.,1.FrequencyResponseof BNCOpenCircuitProbeTip Figure3-2.Input Impedance of BNCOpenCircuitProbeTip G-S-114 G-S-171 100MC1000MC 100MC1000MC 10MC FRfOUENCY IMC ,411A-21CVHFPROBETIP , c!j)411A-21BPEN-TYPEPROBETIP 01193-1 Figure3-6.FrequencyResponseof VHFProbeTip Figure3-4.FrequencyResponse of Pen-Type

23、ProbeTip +3 +2 +1 TYPICAL RELATIVE 0 RESPONSE lOBI-I -2 -3 IOOKC +3 +2 +1 TYPICAL RELATIVE 0 RESPONSE lOBI-I -2 -3 100KCIMC10MC FREOUENCY Q-5-I13 IOOMC1000MC 100MC1000MC 10MC FREOUENCY 10MC FREOUENCY O.OIV RANGE 11-_+-_-+-1- 100KCIMC +II-+-+-j-:;I -2J.II:-+_-_+-_1-; -3-+-_+-I-l 100KCIMC 10Kf-+-7_+-;

24、,L-=.-1 Figure3-3.FrequencyResponseof TypeNTProbeTip lOOK 10f-_+-_-+_-1_I c!j)411A-21BPEN-TYPEPROBETIP SHUNTCAPACITANCE4pf Figure3-5.Input Impedance of Pen-TypeProbeTip IMEG.,=_.-_-,-_-,_-, 411A-210TYPENTCONNECTOR +3,-.,.-r-,-, +2-+-+-1-1 TYPICAL RELATIVE0 RESPONSE lOBI-I TYPICAL SHUNTIK-+-,.+-_+-_l

25、 RESISTANCEO.OIV RANGE (OHMSI1001-+-+-I-f 3-0 Model411ASectionIII Paragraphs3-1to3-15 SECTIONIII OPERATION 3-1.PRELIMINARYCONSIDERATIONS. 3-2.Forthemajorityofyouruses(measuringcontin- uoussinewaves)theModel 411A willindicatethe root-mean-squarevaluedirectly.Whenmeasuring unusualwaveforms,acorrection

26、factormaybenec- essary.Seeparagraph3-27,InterpretingtheRead- ing,forfurtherdetails. 3-7.BNCOPENCIRCUITPROBETIP.Hewleu- Packardstocknumber411A-21E.Frequencyrange 500 kc to 500mc.Maximum voltage 200 volts dcor 30 volts peakac.Typicalfrequencyresponsewith voltage and frequencyisasshown in figure3-1. 3-

27、8.Typicalinputresistancevarieswith voltage and frequencyasshown infigure3-2. CAUTION BE SURE TOGROUNDTHIS INSTRUMENT BEFORE USE. 3-3.Goodrfmeasurementsrequireproperground- ing.TheModel 411Acontainsalinefiltertoelim- inatestrayrffromthepowerline.Therefore, youmustgroundtheinstrumntchassisproperlyto m

28、akesignificantmeasurements.Inaddition,the filterconfigurationissuchthatifyou do not ground theinstrument,itschassisassumesa voltage of aboutone-halfthelinevoltage, and youcandamage circuitsundertest. 3-4.Togroundyourinstrumentproperlyusea NEMA receptaclewith athird-prongground.If,however, youusethe

29、two-prongpoweradaptorbesureto ground thethirdwirepigtail. 3-5.PROBETIPS. 3-6.FiveprobetipsareavailablefortheModel411A. Theseprobetipsenable youtousethe Mode1411A foralmostanymeasuringapplication. Datatoguide you intheselectionoftheproperprobetip follows (shadedareasindicatepossiblevariationsdue to t

30、emperature).Ifyou wishtomakeyourownprobe tipthenecessarydataisalsogiven.Thefollowing probetipsareavailable: 3-9.TYPENfiTPROBETIP.Hewlett-Packard stocknumber411A-21D.Frequencyrange1mcto 1000mc.SWRislessthan 1.15 whenterminatedin 50ohms.Maximum input 10 volts dc and 30 volts ac.Typical frequencyrespon

31、sewith voltage and frequencyisasshown in figure3-3. 3-10.SWRislessthan 1.15 whenterminatedin 50 ohms.Insertionlossislessthan 1 db(lessthan 0.1 db upto150 mc). 3-11.PEN-TYPEPROBE TIP.Hewlett-Packardstock number411A-21B.Frequencyrange500 kc to 50mc. Maximum input 200 volts dc and 30 volts peak ac. Typ

32、icalfrequencyresponsewith voltage andfrequency isasshown in figure3-4. 3-12.Typicalinputresistancevarieswith voltage and frequencyasshown in figure3-5. 3-13.VHFPROBETIP.Hewlett-Packardstock number411A-21C.Frequencyrange500kcto250mc. Maximum input 200 volts dc and 30 volts peak ac. Typicalfrequencyre

33、sponsewith voltage andfrequency isasshown in figure3-6. 3-14.Typical inputresistancevarieswith voltage and frequencyasshown infigure3-7. 3-15. CAPACITIVE DIVIDER(100:1). Hewlett-Packard stocknumber411A-21F.Frequencyrange500 kc to 6-5-17 G-5-211 ICOMC1000MCIMC10MC FREQUENCY +I1-.-4-+-+_., -I o +2t-+-

34、t-+_-_1 -2-+-t-+_-_1 -31-_-1-_4-_-4-_ 100KC TYPICAL RELATIVE RESPONSE lOB) r!i!411A-21FCAPACITIVEDIVIDERPROBETIP +3.-.-r-T-. 100MC1000MC 11-t-i-+_-1 100KCIMC10MC FREQUENCY r!i!411A-21CVHFPROBETIP SHUNTCAPACITANCE22pf IMEGr-cc-.-.,-, lOOK 10K)+-_-.,+-: TYPICAL INPUT RESISTANCE (OHMS)1001-+-+-+-1 101-

35、1-+-+-1 1 1 I Figure3-7.Input Impedance of VHFProbeTip Figure3-8.FrequencyResponse of CapacitiveDivider 01193-13- Section III Paragraphs3-16to3-29 250mc.Maximum input1000volts peak (dc+peak ac).Shunt capacity 2 pf.Divisionaccuracy1%. Typical frequencyresponsewithvoltage andfrequency isshown infigure

36、3-8. 3-16.MAKINGPROBETIPS.Forspecialapplica- tionswherenone oftheseprobetipsaresuitableyou maymakeyourownprobetip.Thesignalmustbe coupled through a blockingcapacitortothecenter conductor(terminal)of the diodecartridge.The ground-returnpath should gototheouterconductor of thecartridge.Theblockingcapa

37、citorusedshould be130 pf1%,!f$stockno. 0150-0067, highleakage resistancetype (mylar), and have a high enoughvolt- ageratingtoblock anydc.Thisblockingcapacitor isnecessaryfortheoperationof themillivoltmeter and shouldbeusedevenifthe signalsourcehasno dc component. 3-17.SELECTIONOFPROBETIP. 3-18.Incho

38、osing theproperprobetip,besidesthe obviousselectionof coaxialornon-coaxial types, otherpropertiesof theprobesmustbeconsidered. Forinstance,at25mceitherthepen-typetiporthe vhf tipmaybe used. However, the vhfhaslessshunt capacity andthereforeshould beusedin highimped- ance applications,orwheretheleast

39、disturbanceto thecircuitisdesired.Inasimilarmannerallthe specificationsfortheprobetipsshould beconsidered whenselectingthebestoneforthe application. 3-19.INSTALLATIONOFPROBETIPS. 3-20.Aftertheproperprobetiphasbeenselected, installitontheprobebodybyloosening the locking collarand unscrewing thepresen

40、tprobetip, if any, andscrewingthenewprobetip initsplace. Screw the newprobetip down untilitjustbottoms. CAUTION Excessivetorquewilldestroythecartridge. 3-21. Screw thecollaruptolock theprobetip in place.Keep the diodecartridgewhich fits intothe probe tipclean.Donot touch thecartridgewhen installing

41、the newprobetip.Run the lockingcollar tightlyagainsttherearof theprobetip (besurethe probe tip does notrotatewhilethelockingcollaris being tightened). 3-22.MECHANICALMETER-ZERO. 3-23. Whenmeterisproperlyzeroset,pointerrests overthezerocalibrationmarkonthemeterscale wheninstrumentis1)atnormaloperatin

42、gtemper- ature,2)initsnormaloperatingposition, and3) turned off.Zero-setasfollows to obtainbestaccur- acy and mechanical stability: 3-2 Mode1411A a.Allowtheinstrumenttooperateforatleast20 minutes;thisallowsmetermovement toreachnormal operatingtemperature. b.Tuminstrumentoff and allow 30 secondsfor a

43、llcapacitorstodischarge. c. Rotatemechanicalzero-adjustmentscrewclock- wiseuntilmeterpointeristo leftofzeroand moving upscaletowardzero. d. Continue torotateadjustmentscrewclockWise; stopwhenpointerisrightonzero.Ifpointerover- shootszero,repeatstepsc and d. e.Whenpointerisexactlyonzero,rotateadjust-

44、 mentscrewapproximately15degreescounterclock- wise.Thisisenough tofreeadjustmentscrewfrom the.metersuspension.If,pointermoves during this stepyoumustrepeatstepsc throughe. 3-24.ZEROADJUSTMENT. 3-25.Procedureforadjusting the ZEROcontrolis given infigure3-9.Asthiscontrolisturnedcounter- clockwiseithas

45、controluntilthemeterreacheszero. Whenthemeterreadsbelowzero,the action of the ZEROcontrolissluggish.However, thezerodoes not always havetobesetaccurately.Aslighterror inzero-settingbecomeslessimportant(at asquare- lawrate)asthe input voltageisincreased.For example,ifthezero-Setisoff 1minordivision,

46、this wouldbeabout 0.8IJ.v of dc, equivalent to about 0.2 mv ofrf.At1 mv ofrf(1/10thfullscale)about 15IJVdcisdevelopedattheprobeoutput, meaning that theerrorinzero-setwould be only5%of the reading.Atfullscaleitwould only be about 0.05%. 3-27.INTERPRETINGREADING. 3-28.Nointerpretationofthemeterreading

47、is necessarywith continuoussinusoidalsignals.This meansforalmostallofyour-measurementstheread- ing onthemeterwill be thermsvalue of the signal. Theusual conditions applythatthe frequency of the signalmustbe in therangeof theinstrumentand the dc componentisnotmeasured. 3-29.When a non-sinusoidal wave

48、formismeasured thereadingobtainedmustbeinterpretedwithrespect totheparticularwaveform beingmeasured.Thedc voltage developedbythesignaliscomparedwith an almostequal dc voltage developed by the sinusoidal voltage from the 100 kcoscillator.Since the wave- formsof the two voltagesaredifferent, the peak voltage neededtodeveloptheseequal dc voltagesis different. 011931 I ( f, I I i I I I Model411A I,U,il(. ., ., .ULl. .,.: ,1$1 no C-0 SectionIII Figure3-9 Theneedle on themetershould beonzerowhen theinstrumentisoff.Ifitisnot,proceedas follows: 1. Adjustmechanicalmeterzero-setasinpara- gr