Kenwood CO-1506 User manual

130mm OSCILLOSCOPE
INSTRUCTION MANUAL
CO-1506

FEATURES
•High 20 mV/cm verticalsensitivityanda wide frequency response upto1.5 MHz.
•Considerablereduction of weight and size as compared with conventional 130mm type
oscilloscopes, allowing perfect portability,
•Moreintensityandcontrastdue tothe use of bluish-greenphosphor (B31) in CRT.
•Verticalstyling for easy installation ina limited space.
CONTENTS
CIRCUIT DESCRIPTION . . . . . . 3 CAUTIONS ON HANDLINGTHESET ...11
PANEL CONTROLS AND THEIR FUNCTIONS . . . 4 MAINTENANCE AND ADJUSTMENT . . . .11
OPERATING INSTRUCTIONS. 6 PARTS LIST . . . ...13
APPLICATIONS 8 PC BOARD 15
SPECIFICATIONS
2
Cathode raytube 130BEB31
Vertical amplifier
Deflectionsensitivity 20 mV/cm or more
Frequency responseDC:DC to1.5MHz (-3dB)
AC: 2 Hzto1.5MHz (-3dB)
Input resistance 1Mnf±5%)
Input capacitance Approx. 35pF
Attenuator 1,1/10,1/100 (within ±5%
inter-rangeerror)
Gain controlVariable upto 22dB or more
Permissible inputvoltage 600Vp-p (DC + ACpeak)
Drift Thermal: 1 mm/°C or less at
20mV/cm
Time: 15 mm/hr or less 15
min. afterswitch on
Overshoot 5% or less on 100kHzsquarewave
Horizontalamplifier
Deflectionsensitivity 500 mV/cm or more
Frequency response DCto 250kHz(-3dB) atthe
maximum point ofH. GAIN
control
Input resistance 1Mn (±20%)
Input capacitance Approx.40pF
Permissible response 100Vp-p
Sweep circuit
Sweep frequency 10to100 Hz, 100to 1kHz, 1 to
10kHz, and10to 100kHz
(continuouslyadjustable be-
tweenranges)
Synchronizing Internalnegativesynchronizing
possible with 10mm amplitude
or less on CRT screen.
Power source AC 100V/117V/230V,50/60Hz
Power consumption 15Watts
Dimensions Maximumwidth:
150mm(154 mm)
Maximumheight:
220 mm (246mm)
Maximumdepth:
410 mm (445mm)
Values in( ) are maximum
dimensions
Weight 6.2 kg (13.7 lbs.)
Accessories Instructionmanual 1
Fuse(0.3A-inthe area of 230V
powersupply)......... 2
Fuse (0.5A-in the area of 117V
powersupply)......... 2
Shielded lead with
banana
plug (CA-46) 1

CIRCUIT DESCRIPTION
VERTICAL SECTION . , ... , . . /
The, input "signalapplied -.to;;; V..- INPUT- passes through the
DC coupler(DC)orACcouplerincorporatinga capacitor
(AC) andisthenfedtotheattenuator;theselection
betweentheDCcouplerandAGcoupleriseffectedby
manipujatingV. INPUT terminals.Theattenuatorprovides
settingof1,1/10or1/100.sothatthe input signalmaybe
attenuated.toa certajn- range.,-ofvoltagethatcanbe
accepted bythe .vertical amplifier,, , ..
The verticalamplifierisa direct-coupleddifferentialampli-
fierconsistingofFETQ1andsilicontransistors;Q2.~Q5,
allowingstableDCamplification.
HORIZONTAL SECTION
The horizontalsectioniscomposedofthesynchronizing
input voltage limiting circuitQ6,time base sawtoothwave
generatorQ7~ Q10,horizontalamplifierQ12~ Q14and
theblankingvoltageamplifierQ11.
The synchronizing input voltage limiting circuit suppresses
thesynchronizingsignal,"pickedup from theemitterofQ5
atthefinalstageoftheverticalamplifier,toa constant
level whichisthenappliedtothesawtoothwavegenerator,
thusassuringstablesynchronization..
The sawtoothwavegeneratorincludesthediodeD1for
stabilizingtheDC level, whilethemultivibratorconsisting
ofQ7andQ8generatessawtooth waves. TransistorQ9
insertedintheemittercircuitoftransistorQ8isa current
limiterwhichimprovesthelinearityofthesawtooth waves.
Transistor Q10invertsthepolarityofsawtooth waves,
performingnegative-to-positive going sweepsoastomeet
therequirements-,inrelationtothenumberofthehori-
zontalamplifierstageswhichfollows.
The horizontal,.arnpjfierisa one-stagedirect-coupled
differentialamplifierconsistingofFETQ12andsilicon
transistors Q13andQ14. This configurationensuresstable
DC amplification.Thatis,a verylowspeedofsweeping
below1 Hzcanbeachieved through H. INPUT terminal
(8)./.,/..;....'..
Intheblankingvoltageamplifier,thenegative going pulses
from theQ8collectorareamplifiedtopositive going pulses
whicharethenappliedtothecathodeofCRT,thus
blankingovera range from 10Hzto100kHzfor ease of
observationontheCRT screen.
POWER SUPPLY CIRCUIT'
The powersupplycircuitprovides+8V and—15V through
thevoltagestabilizerconsistingofzenerdiodesD2andD3,
in addition to180V (approx.) through thefull-wave
rectifiercomposedofthediodesD6andD7tosupplyto
thecollectorcircuitofthefinalstageofeachamplifier.
HIGH- VOLTAGE;POWER: SOPPLY CIRCUIT
Thiscircuit^supplies —1500V through thefull-wavevoltage
doubterrectifiercomposedofthehighvoltagediodesD1
and-02 tothe•••CRT•circuit;""'v
DC
GND
HJNPUTi
GND
X65-1080-00
Attenuator
Sla.b
Synchronizing
voltage frmitet
06
FUSE
0.3A
S3
Inputcircuit
01
Saw-tooth
wave
oscillator
S2a-e 07- 10
Power fransformer,
primaryside
Vertical ;
amplifier
02-5
Blanking
circuit
01 i
Horizontal
/amplifier
0I2~ 14
Power supply
D2 - 7
X68-1130-00
Highvoltage
supply
Dl ,2
Fig. 1 BLOCK DIAGRAMOFCO-1506
3
V. INPUT
AC
-15V f8 V 4- 180V -
1500 V
CRT
130BEB31

PANEL CONTROLS AND THEIR FUNCTIONS
FRONT PANEL
(1)AC
This isthe vertical input terminal coupled toV.ATT
(4) througha capacitortocutoffDCcomponent
containedinverticalinput signal. Itisused on-fy
when ACcomponentistobeobserved.
(2)GND
This istheearthterminalforverticalinput signal.
(3)DC
This istheverticalinputterminaldirectlycoupledto
V. ATT(4).Itisusedtoobserveverticalinputsignal
containingDCcomponent.
(4) VERT ATT
This istheverticalattenuator.Itisusedtoattenuate
a signalvoltagefedtoACterminal(1)orDCterminal
(3) totheamplitudesuitedforobservationonCRT
screen.
When itissettothe1 position,thesignalfedtoAC
terminal(1)orDCterminal(3)isdirectlyfedtothe
vertical amplifier.Atthe1/10or1/100position,the
waveform amplitudeisreducedto1/10or1/100.At
theGNDposition,theinputoftheverticalamplifier
is connectedtotheearth.
(5) POWER
This isthepowerswitch.To turn onthepower,pull
4

theknoboftheswitch;theredmarkontheshaft
appears.
(6)SWEEP RANGE (Hz)
This isthesweepfrequencyselectorswitchandis
used with SWEEP VAR/H. GAIN(10).Itadjuststhe
numberofpeaksofwaveformdisplayedonCRTto
thenumbersuitableforobservation.AttheEXT
position,theamplifiedhorizontalsignalisconnected
toH. INPUT (8) through SWEEP VAR/H. GAIN
(10).
(7) GND
This istheearthterminalforhorizontal input signal.
(8) H.INPUT
This istheexternal input signalterminalforthe
horizontalamplifier.
(9) POSITION
This isthehorizontalpositionadjuster.Itshiftsthe
positionofthewaveformonCRTto left or right. A
clockwise turn willshiftthewaveformto right.
(10) SWEEP VAR/H.GAIN
This isusedtofineadjustsweepfrequenciesandthe
gainofexternalhorizontalsignal.When SWEEP
RANGE (6)issettotheinternalsweeprange(10~
100kHz), itfunctionsasa sweepfrequencyfine
adjustertoadjustthenumberofpeaksofwaveform
onCRT.When SWEEP RANGE (6)issettoEXT
position,itadjuststhegainofthesignalconnectedto
H. INPUT (8),changingtheamplitudeinthehorizon-
taldirectiondisplayedonCRT.Itshouldbenoted
thatthefrequencyresponseofthehorizontalampli-
fiervariesaccordingtothe rotation oftheknob.
(11)V.GAIN
This istheverticalgaincontrol.Itisused with VERT
ATT (4)toadjustthe size ofamplitudeofwaveform
onCRT.Whentheamplitudecannotbeproperly
adjusted with thisknobalone,changethepositionof
VERT ATT(4).
(12)^ POSITION
This istheverticalpositionadjuster.Itisusedto
shiftthepositionofwaveformon CRT. A clockwise
turn willshiftthewaveformupward.
REAR PANEL
(14)INTENSITY
This isthe bright linecontrol.Itisusedtoadjustthe
intensityof light ofwaveformonCRT.A clockwise
turn willincreasethe light intensity.
(15) FOCUS
This isthefocuscontroltoobtainthesharpestimage
ofwaveformonCRT.
(16)CLAMPING SCREW FORTHECRT
(17)CLAMPING SCREW FORTHECRTBAND
SIDE PANEL
(13)DCBAL
This istheDCbalancecontrolforthevertical
amplifier.Itshouldbeadjustedsothatthe bright
linedoesnotshiftwhentheknobofV.GAIN
(11) isturned.
5

OPERATING INSTRUCTIONS
GENERAL METHODSOF OPERATION
A waveformtobeviewedisfedtoV. INPUT terminals(1)
andGND(2)or(2)andDCterminal(3).Adjustthe
controls VERT.ATT (4)andV.GAIN(11)sothatthe
displayedwaveformis40to60mmhighonthevertical
axis. Foradjustments,refertotheitems4 and11ofthe
operatingprocedureoutlinedonthepanel.Thenobtainan
appropriatenumberofwaveformpeaksbyadjustingthe
controls SWEEP RANGE (6)and VAR/H.GAIN (10).The
displayedwaveformmustbesynchronizedtoa steady
state. Ifthewaveformcontainsonlya singlecomplete
cycle onCRT,itmeansthatthetimebasefrequencyis
identical with thefrequencyofthesignalbeingdisplayed.
Incontrast with this,ifthewaveformcontainsfive peaks,
thetimebasefrequencyis1/5ofthefrequencybeing
displayed. Waveformsdisplayed with frequenciesaslowas
below50Hzmay cause flickeringonCRTduetotheslow
movementofspot.
This phenomenoniseliminatedasthetimebasefrequency
getshigherthan50Hz.ByusingtheV. INPUT DC
terminal,theDCcomponentofdisplayedwaveformcanbe
measured orfrequenciesbelow10Hzcanbeviewed.When
observingACcomponentonly,theV. INPUT ACterminal
is used.
The polarityofdisplayedwaveformispositiveintheupper
directionofCRTandintheright-directionwhenviewedin
thehorizontaldirection.
The positionofthewaveformonCRTcanbecenteredby
adjustingthecontrols(9)and(12). Since thewaveform
shifts upordowndependingonthepolarityoftheDC
component,it'mustbecorrectedbyadjustingthecontrol
(12). Ifthewaveformcannotbesetinthecenterofthe
screen evenaftertheadjustmentofthecontrol(12),itisan
indicationthattheDCcomponentistoohighand,
therefore,thecontrols(4)and(11)mustbeadjusted
appropriately until thewaveformiscentered.
To measurethevoltageofthedisplayedwaveform, cali-
bratetheamplitudeofthewaveformappropriatelyusing
the scale onthescreenasa guideandreadthesensitivity
obtained.
Amplitude Amplitude
(Positive squarewave)
With AC-DC selectorswitch
set atpositionDC.
Calculate the voltage according tothe equation below.
Voltage= Amplitudex sensitivity
As an alternative,thevoltagecanbeobtainedbya
proportionalcalculationmethodusinga waveformofa
knownvoltage;forexample,iftheamplitudeofthesignal
having3Vppofvoltageis4 cm(thesensitivityofthe
oscilloscope is3Vpp-f4 cm= 0.75V/cm)andtheampli-
tudeofunknownwaveformis6 cm,then:
3VppXVpp3Vppx 6cm
—_
= —_so„ — = XVpp
4cm6 cm4 cm
Therefore, X = 4.5Vpp
Alllevelsontheoscilloscopeareinpeak-to-peakvaluesand,
therefore,mustbeconverted into correspondingeffective
values sinceeffectivevaluesarecommonlyusedinpractice.
Inthisconversion,however,itshouldbenotedthatthe
relationshipbetweentheeffectivevalueandtheamplitude
varies accordingtothetypeofwaveform.Sometypical
relationshipsbetweentwoaregivenforreference:
Waveforms
Effective values
(rms)
Y=0.5A
2/3"
0.288A
Fig. 2 MeasurementofACandDCcomponents
6
"7?
=0707A
275=0.354A
A
y = 0.5A
l In
With AC-DC selectorswitch
set atpositionAC.

DC voltagesaremeasuredasdisplacementsofthe bright
line through theV. INPUT DCterminal(13).A DCvoltage
displayedontheCRTisdirectlyreadasitseffectivevalue.
MEASUREMENT WITH LISSAJOUS' FIGURES
1. Frequencymeasurement
Lissajous' figuresare often usedasa meansofmeasuring
frequencies ofsignals.Formeasurement,firstsetthe
SWEEP RANGE (6)totheEXTpositionandconnecta
signal generatorbetweentheGND(7)andH. INPUT (8).
Adjustthehorizontalamplitudetoabout4 ~ 6 cm.
Next,applya signalofunknownfrequencytotheAC
terminal(1)andtheGNDterminal(2).Adjustthevertical
amplitudetoabout4 ~ 6 cm.
As thesignalgeneratorisslowlycontrolledforcontinuous
change inthefrequency,the following patternswillappear
atcertainfrequencies(seeFig.4).Asa rule,whenthe
patternisa straightlineora truecircle,itmeansthatthe
unkownfrequencyisequaltothefrequencyofthesignal
generator.
The displayed Lissajours' figurewillonlybecomestationary
whenoneofthefrequenciesisanintegral multiple ofthe
other.Therefore,theunknownfrequencycanbeobtained
bycalculation.
2. Measurementofphasedifference
As inthe case oftheprecedingitem,FrequencyMeasure-
ment,whentwosignalsofthesamefrequencyareapplied
toH. INPUT andV. INPUT (forexample,R andL signals
instereomode),thepatternontheCRTscreenbecomesa
straightlineslanting from theupper right tothelower left if
theyareinthesamephase.Asthesignalsbecomeoutof
phase, the Lissajous' figuregetsmorelikea circleandwhen
thesignalsreacha stateof90°phasedifference,thenthe
patternbecomesa truecircle.Inmeasuringandcalculating
phase differenceswedesignatethehorizontalamplitudeas
"X" andthehorizontalexcursionofthe Lissajous' figureas
"x". Thephasedifferencee isthen found from:
Sin e = x/X
2 : l
(v : H)
Fig. 4 Frequencymeasurementwith Lissajous' figure
Also inthismeasurement,phasedifferencebetweenthe
horizontalandverticalcircuitsoftheoscilloscopeitselfcan
besetto"zero"overa rangeuptoapproximately2kHzby
turning H.CAIN(10)tothemaximumclockwiseposition.
Itshouldbenotedthata measurement with a frequency
above2kHzwill cause an errorinthephase.Thefrequency
rangeinwhichthephasedifferencebetweenV andH is
"zero" isreduceddowntoabout500Hzatthe1/2
positionoftheH.GAIN(10).
Fig. 5 Phase measurementwith Lissajous' figure
7
i: l
I : 2
(v : H)
3 : 2
(v : H)
Sensitivity (V/cm)x A cm= Voltage(V)
Fig. 3 DCvoltagemeasurement

APPLICATIONS
Fig. 6.Representative Lissajous" patterns
MEASURING AUDIOAMPLIFIER FREQUENCY
RESPONSE
Supply a sinewavetotheAUXterminaloftheaudio
amplifier from a signalgeneratorandconnectthespeaker
output terminalsoftheamplifiertoV. INPUT (1)and
GND (2).Theaudioamplifiermayhavea typicalfre-
quencyresponseasshowninFig.8. This response,
however,willvaryasshowninFig.9 byusingthetone
controlorloudnesscontrol.
The amplifierfrequencyresponseshouldbemeasuredby
readingtheamplitudedisplayedonCRTforeachof
differentfrequencieswhilemaintainingthesignalgenerator
ata constant output level.
CAUTION:
WhenH. INPUT (8)is used, thefrequencyresponseofthe
horizontalamplifiervariesaccordingtothepositionofthe
VAR/H. GAIN(10)knob(approximately25kHzatthe
centerposition).
Itisadvisabletoset VAR/H. GAIN(10)tothepositionof
a highestpossibleagain.
Ifthe input signalislarge,themeasurementshouldbe
performed with anattenuatorinsertedbetweentheGND
(7) andH. INPUT (8)asshowninFig.7.Inthis case,
VAR/H. GAIN(10)shouldalsobesettothepositionofa
highestpossiblegain.
ATTENUATION 1/100
Fig. 8 Anexampleoffrequencyresponse
Fig. 7 Connectionofattenuator
Fig. 9 Frequencyresponseaffectedbythetone
andloudnesscontrols
8
180°135°90°45°0°
(225°)(270°)(315°) (360°)
ATTENUATION 1/10

SQUARE WAVESIGNALSAND FREQUENCY
RESPONSE
Use ofa squarewaveinplaceofthesinewave will provide
an approximatefrequencyresponseoftheamplifierby
checkingthe output waveformofthesquarewave.
The abovesameconnectionsalsoapplytotheresponse
check ofTVreceiversforeitherthevideoIForaudioIF
response. Use point B formeasurementsofFMreceiverIF
transformersandtracking,anduse point A fordetector
adjustment.
ALIGNINGTHEIF RESPONSE OFFMORTV
SETS
To checktheoverallresponseoftheintermediatefre-
quencytransformersofan FMreceiver,the SWEEP
RANGE (6)shouldbesettoEXTposition.Thenconnect
the output leadsofa sweepgeneratortothemixerand
chassis ofthereceiverandthesweeep output totheH.
INPUT oftheoscilloscope.Also,connecttheoscilloscope
tothetest point or output terminalofthe limiter ofthe
FM receiver.Thisconnectionmaybemadebyusinga
shieldedcable with about100knresistorprovidedatthe
point ofconnectiontothereceiver.Theoscilloscope
shouldbesettothemaximumsensitivitywhilethesweep
generator output levelshouldbesetaslowaspossible.The
cable from thesweepgeneratorandotherleads from
CO-1506 mustbeadequatelyaway from the body ofthe
receiver ormustnotcrosseachothertoavoidinteraction.
TV receiver
Sweep generator
10.7MHz
76-90MHz
Sweep
generator
Ratio detector
output
4.5MHz
9
Sweeping
output
To theEXT SYNC/H. INPUTterminalofCO-1506
Fig. 10ViewingtheSFfrequencyresponses
To CO-1506
To CO-1506
_Detector
joutputl
FM receiver
Frequency responseofamplifier
Square wave output
lOOHz
I KHz
Gain reducedathigh-frequency
Gain risesathigh-frequency
Gain reducedatlow-frequency
Gain risesatlow-frequency
With loudness control setON.
Gain havingwavingcharacteristiccurve
2
(3j
®
(D

ALIGNING AM RECEIVERS
A typicaladjustment ofAM receivers is that oftheIF
transformers. Connections are madefrom the sweep
generator tothe receiver atthe rotor and stator ofthe
receiver variablecapacitor. The leadsfromCO-1506 are
connected across the volumecontrolvariableresistor of
thedetectorcircuitobserve the detector output.
To CO-1506EXT SYNC/H. INPUT
Fig. 11 Adjusting AM receiver
MODULATIONMEASUREMENT
The CO-1506works ifthe measuredmodulatedcarrier is
below1.5MHz.Connect the modulatedcarrier toV.
INPUT (1)and adjustwith VERT ATT(4)andV. GAIN
(11) to produce an envelopeasshown in Fig. 12.
This modulationenvelope isa result of constantmodulating
frequencywhichwill be displayedwithstability onthe
scope whensynchronizedwithcontrols (6)and (10).
To find the degree of modulation,measuremaximum and
minimumvalues A andB.
A^x 100... Modulation in%
A + B
Anothermethod of modulationmeasurement isthe use ofa
trapezoidalpattern. In thismethod, the modulatedradio
signal tobe measured isfedtoAC terminal (1) with SWEEP
RANGE (6)settoEXT position. In thisset-up, the
modulatingsignalapplied toH. INPUT (8) willproduce a
trapezoid or rectangularpattern onthe scope.Assume the
longerside asA andthe shortside B, then the abovesame
equationapplies to find the degree of modulation.
Commonterminal
Connect thislead to
appropriateterminal
Fig. 13 Method of selecting powersupplyvoltage
10
Fig. 12Howto measuremodulationdegree
A- B .
Sweeping
output
from
the
generator
Tuning circuit
Volumecontrolvariableresistor
in the detectorcircuit
To CO-1506
VERTICAL
INPUT
Sweep generatorconnected atthe 455 kHz
IF input or RF output

CAUTIONS ONHANDLINGTHESET
MAINTENANCE ANDADJUSTMENT
1. Select a placenotexposedtodirectsunbeamfor
installationofthisoscilloscope.Internaltemperature
rise causedbythesunbeammakestheoscilloscope
unstable ordamagesthetransistors.
2. Donotoperatetheoscillociopeina roomwherehigh
temperatureand humidity prevail.
,3. Donotoperatethisoscilloscopeina placewhere
mechanical vibrationsprevailora placenearanequip-
mentwhichgeneratesstrongfluxofmagneticforceor
impulsevoltages.
4. With230V powersupply,use0.3A fuse; with 117V
powersupply,use0.5A fuse. Besuretousethefuseof
correctampere fuse. Also,thevoltageselectorterminals
are locatedontheprintedcircuitboardof bottom side.
CAUTION:
The voltagesettingshouldbeperformedonlyafter
turning thepoweroffsincetheselectorterminalsare
near thedangerous—1600V highvoltagecircuits.
5. Donotapply input voltagetoV. INPUT (7)and(8)in
excess of600Vpp,andtoH. INPUT (6)and(7)in
excess of100Vpp.
6. Thealignmentofthe bright linewillbeaffectedbythe
terrestrialmagnetismdependingonthepositioninwhich
theoscilloscopeisplaced with respecttothepolesofthe
earth. Consequentcorrectionisrequiredintheparti-
cular positionoftheoscilloscope.
Line voltage
(V)
Commonterminal
number
Selector terminals
100
13
15
117
13
16
230
13
17
MAINTENANCE
1. Removingthe case and bottom plate:
Remove thesix screws from the sides, andthetwo
screws from thetopplateofthecabinet,usinga Phillips
head screw-driver.Toremovethe bottom plate,unscrew
thefour screws with a Phillipsheadscrewdriver.
2.Replacingthe fuse:
(a) Removethe bottom plate.
(b) Remove thefuselocatedontheprintedcircuitboard
and replace(seeFig.13).-
(c) Ifthefuseisblown,besuretocheckforthe cause
and correct.Turnthepoweronafterreplacement.
(d) With230V powersupply,use0.3A fuse.
CAUTION:
Before fusereplacement, turn thepoweroffand
discharge allcapacitorsnearthefuseholder.
3.AligningtheCRTbrightline:
(a) Loosenthethree screws (16)clampingthe CRT. The
CRT bandclamping screws (17)shouldnotbe
loosened sincethey hold theCRTinplace(see
Instructionsforrearpanelonpage5).
Screws ofcabinet
Liftup
Removing the case from thecabinet
11
16. CiampingscrewfortheCRT
17. ClampingscrewfortheCRTband
Fig. 14

(b) Place theoscilloscopeinthenormaloperatingposi-
tion with respecttothepolesoftheearth.
(c) TurntheCRTbythecover until the bright lineis
alignedhorizontalonthe screen. TheCRTshouldbe
inclosecontact with the scale plate.
(d) Afteralignment,retightentheclamping screws (16)
alternatelyanduniformlymakingsurethatthe bright
linehorizontalalignmentisnotchanged.
CAUTION:
Be carefulnottotouchtheCRTprintedcircuitboard,
CRT socket,polyethylene-coatedcableandotherhigh
voltagecircuits.Whenchecking into thissection,never
failto turn poweroffanddischargethestoredhigh
voltage.
ADJUSTMENTS
1. DCBALadjustment:
Ifthewaveformbecomesoutofcenterorthe bright line
shiftsupanddownastheV.GAIN(11)isturned,it
shouldbecorrectedbyadjustingDCBAL(13).
Inthisadjustment,the VERT ATT(4)mustbesetto
GND, theV.GAIN(11)tothefullycounterclockwise
position,andthe^ POSITION (12)toa point atwhich
the bright lineisalignedinthecenterofthescope.
Then turn theV.GAIN(11)clockwiseand,ifthe bright
linedeviates,adjusttheDCBAL(13) with a small
screwdriver sothatthedeviationisjustmadeupfor
towardthecenterofthescope,thesameconditionasat
the full counterclockwisepositionoftheV.GAIN(11).
Repeat thisadjustments until the bright line stays
unchangedin both theclockwiseandcounterclokwise
positionsoftheV.GAIN(11).
AdjustmentofDCbalanceshouldbeginapproximately
15 afterswitch-onandtheoscilloscopehasbecome
stable.
2. Adjustmentof VERT. ATT
Remove the bottom plate.Supplya 1kHz(approx.)
square wavetotheACterminal(1)andtheGND(2).
Set the VERT ATT(4)tothe1 positionandadjust
thesignalgeneratorsothatanamplitudeofapproxi-
mately4 cmisobtainedonthescope with theV.GAIN
(11) inthefullyclockwiseposition.
Set the SWEEP RANGE (6)toa positionbetween
100Hz to1kHzandobtaintwotofourpeaksof
waveformonthescope.Makesurethatthewaveformis
idealandshiftthe VERT ATT(4)tothe1/10position.
Increase thegenerator output by20dBsothatthe
waveformisapproximately4 cminamplitude.Ifthe
waveforminthis case isdistorted,adjustthetrimmer
capacitor TC1 foranidealwaveform.
Use aninsulatedscrewdriverforadjustment.Further
shiftthe VERT ATT(4)tothe1/100positionand
adjustTC2forthesamepurpose.
Otheradjustment
Whena 100kHzsquarewaveisappliedtotheAC
terminal(1)andGND(2),theovershootiscorrectedby
adjustingTC3.
The variableresistorVR4isa verticalpositioncontrol.
Withthe$ POSITION (12)settothecenterposition,
adjustit until the bright linecomesinthecenterofthe
scope. ThevariableresistorVR6isalsousedtosetthe
bright lineinthecenterofthescope,whileVR8isused
toadjustthesweep width onthescopetoapproximately
10 cm.
Fig. 15Locationoftrimmerandsemi-fixed
variableresistors
Ideal waveform
Fig. 18Squarewavecharacteristicajustmentbytrimmer
capacitor
12
Waveformforlargetrimmercapacitor
Overshoot(%)= — x 100
a
Waveformforsmalltrimmercapacitor
Vertical frequencyresponseathigh-frequencies
(For example,itbecomes900kHz, —3dB)

PARTS LIST
pel.No. PartNo. Description
AQ1-0258 02
Case
— A10-0424-12
Chassis (1)
-A10-0425-02
Chassis (2)
— A20-0889-12 Panel
-
A40-01 37-03
Bottom plate
_ B19
0141-04
Filter
-
B40-0765-14
Name plate
-B41-0204-04
Name plate (Fuse)
_ B41
0111-04
Voltage indication plated 10~120V)
-
B41-0094-04
Voltage indication (220 ~240V)
-
B50-1289-10
Instruction manual
_
D32-0074 04 Shaftstopper
-
E01-1403-05
CRT socket
-
E23-0557-04
Groundinglugx 2
—
E 30-0 545-05
Powercord (line) with plug
-E30
0436-05
Lead wire
„
F05-3011 05
Fuse (0.3A) x 2
-
F05-5013-05
Fuse (0.5A) x 2
-F10-1535-04 Shielding
plate
-
F11-0210 03
CRT shield
—
F1 5 0145-04
Felt(420x 20)
_
F15-0186-04
Felt(170x 10)
_ G13-0046-04 Cushion
-
G13-0068-04
Cushionx 2
-G13
0042-14
Cushionx 2
-
G 53-0015-14
Antennabush
-
H25-0029-04
Polyethylenebag
_ J03
0010-05
Rubberlegx 4
-
J10-0025-03
Besel
-J20-O298-04
CRT holder
-J21-1326-14
CRT band (1)
-J21-1327-14
CRT band (2)
_
J21-1328-03
Transformerbracket
-J21-1329-04
Printed circuit board bracket(1)
J41 0006 00 Cordbushing
J61-0049-05
Cable wrapping band x 5
-
K01-0058-25
Grip
—
K21-0306-04
Knobx 4
-K21
0290 14 Knobx 2
-
K29-0227-14
Knob(tod)
— L02-0068-15 Power
transformer
-
CRT (130BEB31)
_
X65-1080-01
Vertical, horizontal unit (inthe
areaof117V power supply)
-
X65-1080 21 Vertical,
horizontal unit (inthe
areaof 230V power supply)
-
X68-1130-01 High voltage unit
X67 1040-00
Cord with bananatip(CA-46)
PARTS LIST OFX65-1080-00,21
Ref.No. PartNo. Description
CAPACITOR
C1
C90-0021-05
Metal filry
i
0.1/liF 600WV
C2
CC45SL1H151J Ceramic
150pF
±5%
C3
CQ08S1H152J Polystyrene
1500pF
±5%
C4
CK45B2H103K Ceramic
0.01/uF
±10%
C5
CQ08S1H332J Polystyrene
3300pF
±5%
C6, 7
CE04W1V101M
Electrolytic 100/uF 35WV
C8
CC45CH1H101J
Ceramic 100pF ±5%
C10 CE04W1J010M Electrolytic IMF 63WV
C11
CC45SL1H330J
Ceramic 33pF ±5%
C12 CQ93M1H474M Polystyrene 0.47juF
±20%
C13
CQ93M1H473M Polystyrene
0.047/iF
+20%
C14 CQ93M1H472M
Polystyrene
0.0047/iF ±20%
C15 CC45SL1H391J Ceramic
390pF
±5%
C16 CE04W1J010M Electrolytic IMF
63WV
C17 CC45SL1H470J Ceramic 47
pF
±5%
C18 CC45SL1H150J Ceramic 15pF ±5%
C19 CE04W1J010M Electrolytic 1MF 63WV
C20 CC45SL1H471J Ceramic
470pF
±5%
C21 CC45SL1H331J Ceramic 330pF
±5%
C22 CE04W2A221M Electrolytic 220juF 1
oowv
C23 CE02W2E470 Electrolytic 47/iF
250WV
C24
CE04W2A221M Electrolytic 220/uF 100WV
C25 CE02W2E470 Electrolytic
47MF
250WV
RESISTOR
R1 RN14BK2H904F Carbon
900kft
±1%
1/2W
R2
RN14BK2H1113F Carbon
1 iikn
±1%
1/2W
R3 RN14BK2H994F Carbon 990kfl
±1%
1/2W
R4
RN14BK2H1012F
Carbon ro.ikn-
±1%
1/2W
R5
RN14BK2H105F Carbon 1MH
±1%
1/2W
R6 RD14BB2E105J Carbon 1MH ±5% 1/4W
R7 RD14BB2E103J Carbon 10kfi
±5% 1/4W
R8 RD14BB2E473J Carbon 47kO ±5% 1/4W
R9, 10 RD14BB2E822J Carbon 8.2kJ2 ±5% 1/4W
R11
RD14BB2E470J
Carbon 4712 ±5% 1/4W
R12 RD14BB2E333J Carbon
33kO
±5% 1/4W
R 13,14 RD14BB2E332J Carbon
3.3kH
±5% 1/4W
R15,16 RD14BB2E333J Carbon
33kH
±5% 1/4W
R17-19 .RD14BB2E272J Carbon 2.7kQ ±5% 1/4W
R21,22
RS14AB3D123J
Metal film 12kH ±5% 2W
R23,24
RD14BB2E222J
Carbon 2.2kn ±5% 1/4W
R25 RD14BB2E473J Carbon
47kH
±5% 1/4W
R26 RD14BB2E334J Carbon 330kO ±5% 1/4W.
R27 RD14BB2E473J Carbon 47kft
±5% 1/4W
R28 RD14BB2E102J Carbon 1kl2 ±5% 1/4W
R29 RD14BB2E123J Carbon 12kO ±5% 1/4W
R30 RD14BB2E182J Carbon 1.8kH ±5% 1/4W
R31 RD14BB2E100J Carbon ±5% 1/4W
R32 RD14BB2E124J Carbon 120kH
±5% 1/4W
R33 RD14BB2E222J Carbon 2.2kH ±5% 1/4W
R34 RD14BB2E391J Carbon 390O ±5% 1/4W
R35 RD14BB2E124J Carbon 120kH
±5% 1/4W
R36 RD14BB2E223J Carbon 22kO ±5% 1/4W
R37 RD14BB2E222J Carbon
2.2kH
±5% 1/4W
R38 RD14BB2E563J Carbon
56kH
±5% 1/4W
R 39,40 RD14BB2E123J Carbon 12kO ±5% 1/4W
R41 RD14BB2E471J Carbon 470O ±5% 1/4W
R42 RD14BB2E100J Carbon ±5% 1/4W
R43 RD14BB2E684J Carbon 680kO ±5% 1/4W
R44 RD14BB2E102J Carbon 1kO ±5% 1/4W
13

Ref.No, PartNo. Description
R45
RN14AB3D473J
Metal film 47k£l ±5% 2W.
R46
RD14BB2E103J Carbon10kO
±5%
1/4W
R47
RD14BB2E123J Carbon12kH ±5% 1/4W
R48
RD14BB2E332J Carbon3.3kO ±5% 1/4W
R49
RD14BB2E100J Carbon10O ±5% 1/4W
R50
RD14B.B2E103J
Carbon10kO ±5% 1/4W
R51,52 RN14BK2E4301F
Metal film 4.3ka
±1%
1/4W
R53
RD14BB2E391J
Carbon 390ft
±5% 1/4W
R 54,55
RS 14AB3D223J
Metal film 22kO ±5% 2W
R56
RS14AB3D391J Metal film 390ft ±5% 2W
R57
RS14AB3F152J
Metal film 1.5kft
±5% 3W
R58
RD14CB2E101J
Carbon 100ft
±5% 1/4W
SEMICONDUCTOR
Q1 2SK30A-Q
FET
Q2, 3
2SC535-B Transistor
Q4,5 2SC2258
Transistor
2SC458-C
Transistor
Q10 2SA562-Y
Transistor
Q11 2SC2258
Transistor
Q12
2SK30A 0
FET
Q13.14
2SC 2258
Transistor
D1 1N60 Diode
D2 MTZ8.2JB Zenerdiode
D3 MTZ16JA Zenerdiode
D4,5 V06C Diode
D6,7 V08J Diode
POTENTIOMETER
VR1 R03-1020-05 Variableresistor
VR2
R01-2009-05 Variableresistor
VR3
R03-6007-05 Variableresistor
VR4
R12-100305 Semi-fixedresistor
VR5
R03-8050-05 Variableresistor
VR6 R 1.2-3002-05
Semi-fixedresistor
VR7 R03-3056-05 Variableresistor
VR8 R12-1002-05 Semi-fixedresistor
MISCELLANEOUS
-A22-0169-13 Sub-panel
_ £21-0101-05 Terminalx 5
-E23-0046-04 Terminalx
1 7
-E23-004804 Terminalx 7
_
F 01-0820-04
Heat sinkx 5
F05-3011-05
Fuse (0.3A)
— J13-0020-05
Fuse holderx 2
-
J25 1191-13
Printedcircuitboard
L1, 2 L40-1011-03 Ferri-inductor
S1a, b
S29 1074-05 Rotaryswitch(1)
S2a~e
S29-3006-05 Rotaryswitch(2)
03
S31-2004-05
Slide switch
TC1,2
C05-0010-15
Ceramic trimmer
TC3 C05-0029-15
Ceramic trimmer
N1 NE-2 Neonlamp
14
PARTS LIST OF X68-1130-00
Ref.No. PartNo. Description
CAPACITOR
C1
CE02W2E010
Electrolytic 1juF 25WV
C2~4
C91-0510-05 Oil0.2/uF±20%
2000WV
C5, 6
C91 -0506-05 Oil0.1
mF ±20% 1000WV
RESISTOR
R1
RD14BY2H563J Carbon
56kft ±5%1/2W
R2
RD14BY2H274J Carbon
270kft ±5%1/2W
R3
RD14BY2H104J Carbon
100kft ±5%1/2W
R4
RD14BY2H334J Carbon
330kft ±5%1/2W
R5
RD14BY2H274J Carbon
270kft ±5%1/2W
R6
RD14BY2H824J Carbon820kft±5%1/2W
R7
RD14BY2H564J Carbon
560kft ±5%1/2W
R8
R92-118605
Metal film 1Mft±5%1/2W
R9
RD14BY2H104J Carbon
100kft ±5%1/2W
SEMICONDUCTOR•
D1, 2 SHV-Z3 Diode
MISCELLANEOUS
-
E 23-0046-04
Terminal
-
J25 1192-13
Printedcircuitboard
VR1,2
R 12-8006 05 Variableresistor

PC BOARD
X68-1130-00
X65-1080-00,21
15

KENWOODCORPORATION
©96006 PRINTED IN JAPANB50-1289-10(N)
NOTE:
Thecircuit
elements
maybe
changed
without
noticeowing
toa
technicalinnovation.
CO-1506