Hammarlund_SP-600-J_SP-600-JX_user_Apr_1952.pdf

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1、/L GENERALPURPOSE COMMUNICATIONSRECEIVER MODEL SP-600-JX AND MODELSP-600-J INSTRUCTIONS ISSUE3 -APRIL1952 Manufacturedby THEHAMMARLUNDMFG.CO.INC. 460West34thSt.New York1,New York,U.S.A. ( .sseAJ _t.- -ro -Sv17-5 .r:-.Jvvv-.+1-. INb7 - - no z)au-AiI II-.4JL13lfl. A.1-VIti-.6:Jy holdingtheaudiooutputr

2、elatively constantovera wide variation inthestrengthofreceived signals.This minimizesthevariationofoutputdue to fadingofthe received signalandpreventsblastingandoverloading whentuningthroughsignalsofgreatlydifferent strengthwhile traversing a frequency band.Inthe AVCpositiontheRFMetercircuitisoperat

3、ive for indicationoftuningresonanceandrelativestrengthof received signals.TheRFGAINcontrolisoperative onAVCoperation,whennecessarytocontrol excep- tionallystrongsignalsorto reduce noise,buttheRF meteris less effectivewhentheRFGAINcontrolis below maximum setting.IntheMANpositionthe AVCpotential is re

4、moved fromthecontrolledtubes andthegainofthereceiverismanually controlled bytheRFGAINcontrol. CW-ModulationSwitch-TheCW-MODcontrol intheCWposition energizesthebeatfrequency oscil- latorandconnectsanadditional timing capacitorto theAVCcircuittoaccommodatetheAVCtoslow keying.IntheMODpositionthebeatfre

5、quency oscil- lator is inoperativeandtheconditions are established foreithervoice modulatedortonemodulated signal reception. Beat Frequency Oscillator -TheBEATOSCcon- trol variesthetuningofthe455 kcbeatfrequency oscillatoroverarangefrom zerobeatto plusorminus 3 kilocycles. BFOInjection -TheBFOINcont

6、rol adjuststhe cathode self biasofthebeatfrequency buffer ampli- fier,therebydeterminingtheinjection voltage tothe detector tube. Send-Receive -TheSEND-RECcontrolisa single pole, singlethrowtoggle switch.IntheSENDposi- tionitdesensitizestheRFamplifier, gate, second mixer and3.5mc oscillator tubesdur

7、ingtransmission periods. TuningControlandDials -TheTUNINGcontrol rotatesthemaintuningcapacitor as well asthemain andverniertuningdials.Themain dial has six fre- quencybandscales, calibrated in megacycles, andan arbitraryouterscale.Thevernierdial has anarbitrary ato100 scale.Thenumeralundertheupperor

8、fixed pointerofthemain dial indicatesthenumberofcom- plete revolutionsthathavebeen madebythevernier dialatany setting.Thus,ifthepointerfortheouter scaleofthemain dial indicatesoverthefigure 4and thevernier dial indicates 87.6,thereadingtologfor this setting is read, 487.6.Thisprecise mechanical vern

9、iersystem dividestherotationofthemain dial over each frequencybandinto approximately 600 vernier divisions,withone-half division calibration points. Since itiseasytoestimateone-tenthdivisions onthevernier scale, this divides each frequencyband into approximately 6000 readable settings.Thisper- mits

10、extreme accuracyintheloggingandresetting ofstations. TuningLock -TheTUNINGLOCK,locatedto therightoftheTUNINGcontrol, provides a positive 9 lock forthetuningmechanismwithoutaffectingthe frequency settingwhenitisdesiredtopreventacci- dental shiftingofthetuning. BandChange-EachrevolutionoftheBAND CHANG

11、E.controlturnstheturret, containingthe RFandHFOscillator coil,trimmerand switch contact assemblies, fromonefrequencybandtothenext.The turrethasnostopsandmaybeturnedin either direc- tion desired.Apositivedetentmechanism assures correct locationofthevarious bands.TheBAND CHANGEcontrol simultaneously o

12、peratesthesmall MEGACYCLESbandindicating dial, locatedatthe centerofthepanelandalignsthedial frequency indi- catorwiththeproperscaleofthemain dial. Crystal ControlledHFOscillator -TheXTALS control selects either variablehighfrequency oscillator operationoranyoneofthesix crystal positions,for whichsi

13、milarlynumberedcrystal sockets are provided intheCrystalControlUnit.See SectionIIIInstalla- tion.TheDELTAFREQcontrol compensatesforthe small frequency tolerancetowhichthecrystals are made. MeterSwitch-TheMETERswitchisa double pole, doublethrowtoggle switchwithspringreturn totheRFposition. See Sectio

14、nIICircuit Description, TuningMeter. TuningMeterControls -TheMETERADRF control is usedtoadjusttheresistanceshuntingthe meterwhentheMETERswitch isinthenormal,or RFposition.Itisadjustedtoproduce a readingof plus 20dbontheRFscaleofthemeter,witha 10 microvoltRFinputsignalandwiththeAVC-MAN switchintheAVp

15、position.Depressionofthe METERswitchtotheAFposition convertsthemeter circuit for indicationoftheAFpoweroutputlevelin dbfrom 6 milliwatts.Thisswitch is springreturnto theRFpositionwhenreleasedandshouldnotbede- pressedfortheAFscale unlesstheaudiooutputhas been adjusted for lowpoweroutput,bymeansof hea

16、dphonesorspeaker. Failuretoobserve this precau- tionmayresultindamagetothemeter.TheMETER ADAFcontrolisused to regulatethemetercurrent whenoperatingontheAFscale.Thiscontrol is adjusted toobtainaadbreading ontheAFscaleof themeterandis madewiththeaudiopoweroutput fromthe600ohmAUDIOOUTPUTterminals ad- j

17、ustedto6 milliwatts,or1.9 volts across a 600ohm resistive load. Preliminary toOperation-Turnthepower switch onbyturningtheRFGAINcontrol clockwiseand a.dvance this control to10.Notethatthedial lamps hght. PlacetheSEND-RECswitch onRECandturn theBANDCHANGEcontroltothefrequencyband inwhichit is desired

18、to operate.Thisshouldbedone atleast15minutes before usingthereceiver, inorder to permitthetubes towarmup.Inserttheheadphones pluginthePHONESjackoruse speaker as desired. See Installation, Section III. MCWReception -TurntheTUNINGLOCKto its extreme counter-clockwise position andturnthe SELECTIVITYswit

19、ch to 3 kc.PuttheCW-MOD switchonMOD,theLIMITERswitchtoOFF,the AVC-MANswitchonAVC,theXTALPHASING controlatitscenterpositionandturntheXTALS switch toVFO.WiththeBANDCHANGEcontrol intheproperposition forthefrequencybanddesired, as indicatedbytheMEGACYCLESdial, advancethe AUDIOGAINcontrol until some nois

20、e is heard.Turn theTUNINGcontrol to indicatethedesired fre- quencyonthemain dialandtunethesignal for maxi- mum responseorindicationontheRFMeter.At ,resonancethemain dial reading shouldbewithinone- quarterofonepercentofthesignal frequency. Read- justtheAUDIOGAINcontrolforthedesiredoutput level and as

21、 required topreventoverloading.Care- fullytightentheTUNINGLOCKbyturningclock- wise,ifdesired.TheSELECTIVITYswitchmaybe turnedtothe8 kcor13kc positionforimprovedhigh frequency response ifthesignaltonoise ratio is suffi- ciently high.Ifthenoise level is high,theSELEC- TIVITYswitch shouldbeturnedtotheb

22、andwidth whichprovidesthemost intelligible receptionandthe LIMITERswitch shouldbethrownon.Ifthe SELECTIVITYswitchisusedoneitheroftheXTAL positions,theXTALPHASINGcontrol may be ad- justed toeithersideofits center positiontoattenuate an adjacentinterferingsignal.TheRFGAINcontrol may beturneddownsomewh

23、at to reduce noise,during stand-by periods inthetransmission,whentraversing thetuningrange,orduringdeep fadesofthesignal. TheRFMeterscale calibrationisformaximumRF GAINcontrol operationandindicates onlywhenthe AVC-MANswitchisonAVC.Whensearching for very weak signalstheCW-MODswitch maybe throwntoCWan

24、dtheBEATOSCcontrol setatO. Locateandtunethesignaltoobtain zerobeatand thenthrowtheCW-MODswitch backtoMOD. TheCrystal FrequencyControlmaybeused for fixed frequency operationatanysignal frequency for whichcrystalshavebeenprovided.See SectionIII, Installation.TurntheXTALSswitch tothenumeral correspondi

25、ng tothatonthepanelchartforthede- sired signal frequency.Setthemaintuningdial tothe signal frequencyandadjusttheDELTAC controlto obtain zerobeatwiththeCW,MODswitchonCW andtheBEATOSCcontrolatO.ThrowtheCW- MODswitch toMODandadjusttheTUNINGCon- trol for maximumRFMeterindicationorfor maxi- mum response.

26、 CWReception -Thepreliminary procedurefor CWreception isthesame asforMCWreception above. PlacetheCW-MODswitchonCWandwith theBEATOSCcontrolat0,tunethedesired signal for zero beat.AdjusttheBEATOSCcontrol,in eitherdirection, to obtaintheaudio pitch desired.The AVC-MANswitch maybeused inthepositionwhich

27、 givesthebest reception.Adjustthedesiredoutput levelbytheAUDIOGAINcontrolwhenonAVC andbytheRFGAINcontrolwhenonMAN.The RFMeterdoesnotoperate ontheMANposition.The SELECTIVITYswitch maybeusedintheXTAL positions, asfounddesirable, to reduce noiseorto provide rejectionofaninterfering signal.TheXTAL PHASI

28、NGcontrolisadjustedforminimum interfer- ence from an adjacent, interfering signal.Ifinterfer- enceofthis kind persists,furtherdiscrimination be- tweenthedesiredandtheundesired signals maybe realizedbyslightly detuningthedesired signal tothe opposite sideofresonance fromthatonwhichthe undesired signa

29、lislocatedandreadjustingtheXTAL PHASINGcontrolandtheBEATOSCcontrolfor the desired signal.TheCrystal FrequencyControl may be used as describedunderMCWReception above. Ifreception istobesuspendedandresumedat shorttime intervals,thepowershouldbelefton andforsuch operationtheSEND-RECswitch should bethro

30、wntoSENDbetweenreception periods.This keepsthereceiverwarmandreadyforinstantuse. Whenoperationofthereceiveriscompleted,turn thepoweroffbyextreme counter-clockwise rotation oftheRFGAINcontrol. V MAINTENANCE General-Thisreceiverisdesignedforcontinuous dutyandshould normally require little attention be

31、- yondthereplacementoftubes.Anoccasional cleaning ofthegearteethinthegeartrainisrecommendedto preventaheavyaccumulationofdustwhichmay cause calibrationerrorandimproper operationofthe gears.Thismaybedonewitha small stiff bristle brush,turningthecontrols toobtainaccesstothe different portionsofthegear

32、s.Nogreaseoroil should beusedonthegears.Operationandmaintenanceof thereceiver willbegreatly facilitatedifthecontents ofthis instructionbookarethoroughlydigested. Some sectionalizingoffaults is possible, ifthefault isnotexistant on allofthefrequency bands.Non- operationofthethreelower frequency bands

33、,with normal operation onthethreehigherfrequency bands, indicatesthatthefault is associatedwiththecircuits oftubeV7.Ifonlythethreehigherfrequencybands are affected,thefault is associatedwiththecircuits ofV6orV8.Ifonlyonesinglebandis affected,refer toHFOscillatorandRFCoil Assembliesinthis section. Vi

34、sual evidenceoftroubleisusually aburnedor darkened resistor,whichiffoundis likely causedby excessivecurrentduetoashortcircuited capacitoror tubeelementattheload sideoftheresistor.Insuch a case,boththecapacitorortubeandtheresistor shouldbereplaced as indicated.RefertoFigures 10 to16andTable5 for loca

35、tionandvaluesofcom- ponents.Ifthechecksontubes, fusesandvisual inspection fail to disclosethefault,thetubesocket voltagesandresistancesshouldbemeasuredand checked againstthevalues giveninTables 1and2. Anyappreciable departure beyond a normal variation 10 ofapproximately15percentfromthevalues in thes

36、e tables will generally indicatethecomponentorcircuit at fault.Iftheforegoing doesnotrevealthefault, thena stagebystage checkofamplification shouldbe made asshowninTable4.Anygreatdifferencefrom thevaluesofinputshowninthetable will indicatethe stageatfault.Ifatunedcircuit component, such asan IFtrans

37、former,RForHFoscillator coil assembly, is founddefectiveandreplacedonlythereplacedunit needberealigned. Followthealignmentprocedurein SectionVI,fortheunitinvolved. TheIFTransformers,Crystal Filter,BeatFrequency Oscillatorandthe3.5 mc CrystalControlledOscillator assembliesareeachmountedonthechassisin

38、depen dentlyoftheirrespective shields.Theshield can as sembliesareeasily removedforinspectionofthese units,withoutdisturbingthesoldered connections.In replacing these shields, make surethatthegrounding springs are in placeontheinductanceadjusterscrews beforetheshield is installed. VacuumTubes-Weakor

39、defective vacuumtubes arethemost common causeofdecreaseinsensitivity, faultyperformanceorfailureofoperation inare ceiver.Incaseofsuchfaults, first rel)J.ovethetubes andchecktheminatubetesterofreliable design.Ifa tubetesterisnotavailable, substitutionofanewtube foreachtubetypeandpositionshouldbe trie

40、d.See Figures 2and3.Suchsubstitution is best made, one tubeata timeinorderthatthefaultytubemaybe detectedbytheimprovementorrestorationofper formancebythenewtube. Locating Faults -Ifthedial lamps donotlight whenthepowerswitch isturnedon, checkfora blown line fuse,Flandreplaceitattherearofthereceiver

41、fromthespare fuses.Anopencircuit intheline cord orplugmay be checkedbyplugging a lamp first in thepowersource receptacleandthenintheacre ceptacleontherearofthereceiver.Ifthedial lamps lightbutthereisnosoundatallintheheadphones orspeaker, checkforablownminus B fuse, F2andif blown, replaceitwitha spar

42、e fuse.Inreplacing fuses, makesurethatonlya3ampere fuse is insertedinthe line fuseholderandthatonlya%ampere fuse is insertedintheminus B fuse holder.Shouldneither fusebeblown,norreplacementofthefuses restore operation,thereceiver shouldberemovedfromits cabinetorrackandinspectedforvisual signsof trou

43、ble.Thetable model receiver isheldinthecabinet bytwoscrewsthroughthecabinetbottomandbythe fourscrewsthroughtheslotted holesateach sideof thefrontpanel.Therack model receiver isprovided withbottomandtopcover plateswhichshouldbe removedforpurposesofinspectionandrepair. IFTransformers-Ifa fault is trac

44、edtooneofthe variable coupledIFTransformers,T4orT5,check whetherthefault existsonall positionsoftheselec, tivity switch S5,oronlyononepositionofthisswitch. Ifthefaultyoperationoccursononlyoneswitch position, checkforcontinuityofthecoupling coil associatedwiththatposition,checkforimperfect soldered c

45、onnectionsatthecoilandswitch terminals andchecktheswitch contact involved.Iffaultyopera tionlocalizedatonetransformerexistsonall positions 11 oftheselectivity switch, makethecontinuitycheckon theplate. coils,onthemain grid coilandonthewiring associatedwiththese coils.Transformers14andT5 andCrystalFi

46、lterT3haveadditionalinnershield assembliesthatareheldinplacebythetensionnuts ontheadjusting screws.Toremove these shields, hold theadjusting screwswitha screwdrivertoprevent turningthescrewsandlosingthealignmentadjust, mentandloosenthetensionnuts,usinganothersmall screwdriverengaging oneoftheslots.W

47、henreplac ingtheseshieldsandtension nuts, employthesame methodandtightenthetensionnutsjustenoughto preventtheadjusting screws fromworkingloose. BeatFrequencyOscillator -Toremovethebeat frequencyoscillatorT6,ifthereceiver is equipped withtheCrystalFrequencyControlUnitT34,it will benecessarytosetthecr

48、ystal selector switch S2,on itsnumber3 positionandloosenthefourset screws intherigidshaftcouplingandthetwosetscrews in thediscontheselector switch shaft. Slidetheswitch shaftforwardthroughthecouplinganddisc.Itmay be necessarytoremoveburrs,causedbytheset screws, fromtheswitchshaftinordertoslidethesha

49、ft throughthedisc.Nowloosenthefourset screwsof theflexible couplingontheBFOshaftsandslidethe couplingforwardontheBFOdriveshaftinthefront panel.RemovetheBFOshaftbearingbracketby takingoutthetwoscrewsholdingittothechassis. Unsoldertheleadsfromthesix terminalsoftheBFO unitattheundersideofthechassis,beingcarefulto notoverheatthewireoftheshielded cable sincethis wireis insulatedwithpolystyreneandis easily dam- agedbyheat.Notethatifthis cablewireisgrounded toits shield,therewillbenobeatfrequencyvoltage inputtothebuffertubeV12eventhoughthebeat oscillator isfunctioningproperly.Therefore,