Kenwood CS-1352 User manual

TRIGGEREDSWEEPOSCILLOSCOPE
INSTRUCTION MANUAL
CS-1352
DUAL TRACEOSCILLOSCOPE

FEATURES
*Vertical axis provideshighsensitivityandwide
bandwidth,2 mV/div,15MHz(-3dB).
*OperatesonAC,internalDCandexternalDC,
each beingselectedautomatically without using
powerselectorswitch.
*TheadoptionofIC's throughout circuitry assures
highperformanceandimprovedreliability.
*ThehighvoitagepowerforCRTaswellasthe
powerforothercircuitsisfullystabilized,thus
thesensitivityandluminancearecompretely
free from effectsofvoltagevariations,
*X-Yoperationispossible with CH2amplifier
used asX axis.
The horizontal axis sensitivityisashighas10
mV/div, permitting accuratecalibrations.
*Sumanddifferencebetween2 channelscanbe
measured bytheuseofmodeselectorswitch
and CH2selectorswitch.
CONTENTS
Page
Features ^
2
Specifications
Controlson Panels *
Operation^
Preliminary Operation^
OperatingProcedures^
Power Supply®
Battery Charging8
Mounting ofHood®
Applications^
Dual-trace Applications^
Single-channel Applications1^
FM Receiver Adjustments21
X-Y OperationsApplications21
AmplifierSquareWave Test 23
PRECAUTIONS 28
MAINTENANCE AND ADJUSTMENT
Maintenance28
Adjustment29
SCHEMATIC DIAGRAM31
*Time base switchallowschangeoverbetween
CHOP andALTandbetweenV (vertical)andH
(horizontal)ofTV sync separatorcircuit,
automaticallyandelectronically.
*At AUTO positionof TRIG LEVEL, itispossibleto
check theluminanceatno-sighaltimeandtoad-
just triggering levelof input waveforms.
*Theemploymentof digital switchcircuitand
mechanical partscleverlymountedoncircuit
boards assure improvedreliability.
*Theover-dischargeprotectioncircuit
automaticallyshutsoffthebatterycircuitwhen
batteryvoltageislow.
*The built-in chargingcircuitpermitsthebattery
tobechargedwhiletheoscilloscopeisinuse.
1

SPECIFICATIONS
Type ofCathodRayTube:
C331P31B
AccelerationVoltage:
Approx.1.5kV
VerticalAxis(for both CHIandCH2)
Sensitivity:
2 mV/div~10V/div,±5%in1-2-5sequence(1
div=0.6 cm)
Vernier control for fully adjustablesensitivity
betweensteps.
Input Impedance:
1MS2 ±5%.
Input Capacitance:
Approx.22pF
Frequency Response:
DC DC-15MHz (less than-3dB)
AC 10Hz-15MHz (less than-3dB)
Rising Time:
Less than23nsec.
Over-shoot:
Less than3%(at100kHzsquarewave)
Cross-talk:
Betterthan70dBat1 kHz
OperatingMode:
CH1: Channel1 only
CH2: Channel2 only
DUAL. 2-channel (CHOP andALTare
automaticallyselectedby SWEEP
TIME/DIV) 0.5/xs/div~ 0.5ms/div:
ALT (alternatesweep) 1 ms/div~
0.5s/div: CHOP
ADD: 2-channelalgebraicsum(CH1+CH2)
InvertPolarity:
CH2 only
CHOP Frequency:
200kHz±20%
Maximum Input AllowableVoltage:
600Vp-por300V(DC+ ACpeak)
SweepCircuit
Sweep System:
Triggeredandautomatic.Inautomaticmode,
sweep is obtained without input signal
Sweep Time:
0.5;us/div~0.5s/div±5%in19rangesand
"X-Y", in1-2-5sequence. Each overlapping
rangeprovidesforfineadjustament
Magnifier:
5 times±5% (PULLx 5 MAG)
Linearity:
Betterthan3%(2)us/div~ 05s/div)
Betterthan5%(0.5jus/div~ 1/is/div)
Synchronization
Sync Input:
INT: Mode switchchangeover,CH 1 at
DUAL
EXT
Sync Selection:
NOR: positiveandnegative
TV: positiveandnegative
(TVH andTVVareautomaticallyswitchedby
SWEEP TIME/DIV)
TVH (TV- Line):0.5Ms/div~ 50jts/div
TVV (TV- Frame):0.1ms/div~ 50s/div
Sync Range:
Sync
Position
Sync
Frequency
Min.syncvoltage
(amplitude)
Sync
Position
Sync
Frequency
INT
EXT
20Hz~5 MHz 05 div 0.5Vp-p
NOR
20Hz~10MHz 1 div 0.5Vp-p
20Hz-15MHz
1 div
1 Vp-p
(AUTO)
50Hz-15MHz 1 div
1 Vp-p
TV TV
signal 1 div
1 Vp-p
External sync input voltage:
50V (DC+ ACpeak)
HorizontalAxis(CH2 input)
OperatingMode:
X-Y modeisselectedby SWEEP TIME/DIV
CH 1:Y axis
CH2: X axis
Sensitivity:
Same asCH1
(2 mV/div~ 10V/div± 5%)
Frequency Response:
DC DC-1MHz (less then -3dB)
AC 10Hz-1MHz (less than-3dB)
Input Impedance:
Same asCH 1 (1M12±5%)
Input Capacitance:
Same asCH 1 Approx.22pF
CalibratingVoltage:
1 Vp-p±3%positive.(1kHz±5%squarewave)
Luminance Modulation
Input Voltage:
Lightsat+ 5Vor less
2

Input Impedance:
10kfi±20%
Frequency Response:
DC ~ 1 MHz
Maximum Input AllowableVoltage:
50V (DC+ ACpeak)
PowerSource
AC
Power SupplyVoltage:
100/120/220/240V ±10%.50/60Hz
Power Consumption:
Approx.25W
Battery(Option)
Power SupplyVoltage:
12V
ContinuousOperationTime:
More than2 hours with fully chargedbattery
DC
Power SupplyVoltage:
1 1 ~ 15.5V
Power Consumption:
Approx.20W
Charging
Charging System:
InternalbatteryischargedbyconnectingAC
linecord
ChargingTime:
Charging during operationApprox.28H
ChargingonlyApprox.16H
AmbientTemperatureand Humidity:
0~ 50°C,95%or less
Dimensions andWeight
Width:
210 mm
Height:
136 mm
Depth:
348 mm
Projectionsnotincluded.
Weight:
6.5kg (without battery)
8.3kg(withbattery)
Accessories
Probe:
PC-29 2
Damping1/10
Input impedance10MQ
Input capacitance less than18pF
Pin-plug:
1
Replacement fuse:
0.5A2
1A 2
Hood (BF-6) 1
External powerconnectorplug1
InstructionManual:
1 copy
External powerconnector plug 1
Optional accessories:
Shoulderbag(MC-75)
Batterypack (BP-7E)
3

CONTROLS ONPANELS
FRONT PANEL
4
Fig. 1
SIDEPANEL
Fig. 2

1. $ POSITION a
VerticalpositionadjustmentforCH1traceand
Y positionforX-Yoperation.Waveformscan
besettoanydesiredverticalposition.Turning
this control tothe right willshiftwaveformup-
ward, andvice versa.
2. INPUT
Vertical input terminalofCH1(orY inX-Y
mode).
3. AC-GND-DC
DC Direct input ofACandDCcomponent
of input signal.
GND Openssignalpathand ground input to
verticalamplifier. This providesa zero-
signalbaseline,thepositionofwhich
can beusedasa referencewhenper-
forming DCmeasurements.
AC BlocksDCcomponentof input signal.
4. VARIABLE
Verticalattenuatoradjustmentprovidesfine
control ofverticalsensitivity.Intheextreme
clockwise (CAL)position,thevertical
attenuatoriscalibrated.
5. VOLTS/DIV
VerticalattenuatorforChannel1;provides
coarse adjustmentofverticalsensitivity.Ver-
ticalsensitivityiscalibratedin12steps from 2
mVto10voltsperdivisitonwhen VARIABLE
control (4)issettotheCALposition.
6. MODE(CH1,CH2,DUAL,ADD)
CH1: Onlythe input signaltoCH1isdis-
playedasa singletrace.
CH2: Onlythe input signaltoCH2isdis-
playedasa singletrace.
DUAL: Intherangeof0.5s/divto 1 ms/div,
the input signalsto both channelsare
switchedbyabout200kHzsignal
(CHOP operation).
Intherangeof0.5ms/divto 0.5ms/-
div,the input signalsto both
channels arealternatelyswitchedfor
each sweep(ALToperation).
ADD: Thewaveforms from Channel1 and
Channel 2 inputsareaddedandthe
sum isdisplayedasa singletrace.If
thechannel2 polarityswitch(11)is
pulledout (PULL INV),thewaveform
from Channel2 issubtracted from the
Channel 1 waveformandthe
differenceisdisplayedasa single
trace.
7. VOLTS/DIV
VerticalattenuatorforChannel2 which
providesstepadjustmentofverticalsensitivi-
ty.Verticalsensitivityiscalibratedin12steps
from 2 mVto10voltsperdivisionwhen
VARIABLE control (8)issettoCALposition.
This control adjustshorizontalsensitivitywhen
the SWEEP TIME/DIVswitch(21)isintheX-Y
position.
8. VARIABLE
Verticalattenuatoradjustmentprovidesfine
control ofverticalsensitivityofCH2(orX).
This control becomesthefinehorizontalgain
control whenthe SWEEP TIME/DIVswitchis
intheX-Yposition.
9. AC-GND-DC
DC Direct input ofACandDCcomponent
of input signal.
GND Openssignalpathand ground input to
verticalamplifier. This providesa zero-
signalbaseline,thepositionofwhich
can beusedasa referencewhenper-
forming DCmeasurements.
AC BlocksDCcomponentof input signal.
10. INPUT
Vertical input terminalforCH2(orX).
11.
A
POSITION, X-Y^
VerticalpositionadjustmentforChannel2
trace. Becomeshorizontalpositionadjust-
mentwhen SWEEP TIME/DIVswitch(21)isin
theX-Yposition.Push-pullswitchinverts
Channel 2 signalwhenpulledout(CH2
POLARITY PULL INV),non-invertedsignal
whenpushedin.
12. POWER LAMP
Lightswhenscopeison,dimswhenbatteryis
low,goesoffwhenbatteryistoolowfor
operation.
13. CHARGE LAMP
Lightswhenbatteryischarging,goesoffwhen
batteryis fully charged.Chargeroperates
whenever scopeisconnectedtoACpower,
regardless ofwhetherscopeisturnedonoroff.
14. POWER/INTEN
Fully counterclockwise rotation ofthis control
(OFF position)turnsoscilloscopeoff.
Clockwise rotation turnsoscilloscopeon.
Furtherclockwise rotation ofthe control
increases theintensityofthetrace.
5

15. FOCUS
Spot focuscontroltoobtainoptimum
waveformaccordingtobrightness.
16. SOURCE
Selects triggeringsourceforsweep.
INT: Sweep istriggeredbythewaveform
beingviewed:inDUALandADD
modes, sweepistriggeredbyCH1
signal.
EXT: Sweep istriggeredbythesignal
appliedtoEXT TRIG jack(29).
17. SYNC
Sync separatorswitch.Itpicksup sync signal
componentinTVvideosignalandappliesto
sync circuitforcompletesynchronizationof
videosignalbeingviewed.
NOR: Usedforviewingallwaveformsex-
cepttelevisioncompositevideo.
TV: The sync pulsesofa televisioncom-
positevideosignalareusedtotrigger
thesweep;thevertical sync pulses
(TVV-frame) areautomatically
selected forsweeptimesof05s/div.
to01ms/div.,andhorizontal sync
pulses (TVH-line)areautomatically
selected forsweeptimesof50jus/div.
to0.5/Lts/div.
18. SLOPE
Sunc polarityselectorswitch.Atthe" + "
position,sweepiseffectedwithpositiveslope,
and atthe" —"position,itiseffectedwith
negativeslope.
19. TRIG. LEVEL
Sync leveladjustmentdeterminespointson
waveformslopewheresweepstarts;(—)
equals mostnegative point oftriggeringand
( + ) equalsmostpositive point oftriggering.
PULL AUTO:
Push-pull switch selects automatictriggering
when pulledout (PULL AUTO). When
automatictriggering,a sweepisgenerated
without aninputsignal.
20. POSITION
Horizontalpositionadjustertoshiftwaveform
toanydesiredhorizontalposition.A right turn
oftheadjusterwillshiftthewaveformto right,
and vice versa.
PULL X5MAG:
Sweep magnifierswitch.Bypullingtheknob
towardyou,waveformismagnifiedto5 times
inleftand right directions.Brightnessis
slightly decreased.
21. SWEEP TIME/DIV
Horizontalcoarsesweeptimeselector.
Selects calibratedsweeptimesof0.5/us/div.
to0.5s/div.,in19stepswhen VARIABLE
control(22)issettotheCALposition(fully
clockwise). IntheX-Yposition,thisswitch
disables theinternalsweepgeneratorand
permitstheCH2inputtoprovidehorizontal
sweep.
22. VARIABLE
Fine sweeptimeadjustment.Intheextreme
clockwise (CAL)position,thesweeptimeis
calibrated.
23. CAL1 Vp-p
Provides calibrated1 kHz,1 voltpeak-to-peak
square wavecalibrationsignal. This isusedfor
calibrationoftheverticalamplifierattenuators
and tocheckthefrequencycompensationad-
justmentoftheprobesusedwiththeos-
cilloscope.
24. HANDLE
Use thishandletomounttheoscilloscopeina
slant position.
25. AC VOLTAGE SELECTOR
The CS-1352 maybeoperatedfrom100V,
120V, 220V,240V, putting theAC VOLTAGE
SELECTOR intheplaceofanother.
26. FUSE HOLDER
For 220~ 240Voperationa 0.5amperefuse
shouldbe used.
For 100~ 120Voperationa 1 amperefuse
shouldbe used.
27. POWER CONNECTOR
For connectionofthesuppliedACpowercord.
28. INTMOD
Intensity(brightness)modulationterminal.
Intensityismodulatedatvoltagesof+ 5V.
29. EXT TRIG
External sync inputterminal.Forexternal syn-
chronization,setthe SOURCE switch(16)to
EXT toapplyexternal sync voltage.
30. ASTIG
Astigmatismadjustmentprovidesoptimum
brightnessandspotroundnesswhenusedwith
the Focus knob.Very little readjustmentof
thiscontrolisrequiredafterinitialadjustment.
31. EXTDC
6

External DCpowerjacktosupply11~ 1 5.5V
DC power.
32. VOLTAGE NAMEPLATE
Be suretousevoltageandfusespecified.
33. CORD REEL
Used towindpowercordwhentheos-
cilloscopeistobecarriedorstored.Italso
serves asa standwhentheoscilloscopeis
used in upright position.
OPERATION
PRELIMAINARY OPERATION
Whenoperatingthisoscilloscope,refertopanelcontrolsandtheirfunctions.Whenstartingthisoscilloscope
set initially,settheoperatingcontrolsasfollowsandthesetmaybeturnedonsafely.
Fig. 3
OPERATING PROCEDURES
1. Selectthe position ofthepowervoltage selec-
tor plug asindicatedbythearrowmarks.Then
insertthesuppliedpowercordtothepower
connector.
2. Turn POWER/INTEN (14)clockwise.The
poweristurnedtoONand POWER lamp(12)
lights.
3. Horizontal axis will bedisplayed.Whenfly-
back linedoesnotappearatthecenterofthe
screen, adjust^ POSITION (1)and
^•POSITION PULL X5MAG(20).
Adjustbrightnessby POWER/INTEN (14).If<-
tracelineisunclear,adjust FOCUS (15).
4. Theoscilloscopeisnowreadyformeasure-
ment.Formeasurement,proceedasfollows:
Applysignalvoltagetothe input terminals(2)
and(10).Then turn the VOLT/DIV (5),
clockwise until thewaveformiscorrectlydis-
playedonthe screen. BysettingtheMODE
switch(6)toCH1andthe SOURCE switch
(16) toINT,theCH1 input signalto INPUT ter-
minal(2) will appear.WhentheMODEswitch
(6) issettoCH2,thenthe input signalto
INPUT terminal(10) will appearonthescope.
WhentheMODEswitch(6)issetto DUAL,
twowaveforms(CH1andCH2) will appearon
thescope,atthistime,theCH1signaltothe
INPUT terminal(2)isfedtothesyncrocircuit
wheretheCH 1 signalissynchronized.When
theMODEswitch(6)issettoADD,theCH1
signalisalgebraicallyaddedtotheCH2signal
(CH 1 + CH2).By pulling CH2 POLARITY
(11), theCH2signalinreverse polarity isadd-
edtotheCH1signalandthealgebraic
7

differencebetweenCH1andCH2isdisplayed
(CH1 - CH2).
5. Whenthesignalvoltageismorethan2mVand
waveformfailstoappearonthe screen, theos-
cilloscope maybecheckedbyfeedinginput
fromCAL1 Vp-p(23). Since calibration
voltageis1 Vp-p,thewaveformbecomes5 div
highatthe0.2/divposition.
6. Bypushing TRIG LEVEL (19).thefree-running
autofunctionis released. Thewaveformdis-
appears whentheknobisturnedclockwise,
and appearsagainwhenitisreturnedtoitsap-
proximatemiddlepositionofit. Sync phaseis
also adjustableinthis case. Thewaveformwill
again disappearwhentheknobisturned
counterclockwise fromthemidposition.
7. WhenDCcomponentismeasured,set
AC-GND-DC (3)or(9)toDCposition.If,in
this case, theDCcomponentcontainsplus
"+ " potential,thewaveformmovesupward
and ifitcontainsminus" —"potential,the
waveformmovesdownward.
The reference point of"0"potentialcanbe
checked atGNDposition.
POWER SUPPLY
The oscilloscopeisdesignedtooperateonAC,in-
ternalbatteryorexternalDC.
AC operation
For ACoperation,firstsetthepowervoltage selec-
torswitchtothevoltageofyourlocalACcurrent.
Then, connecttheACcord.Theconnectionofthe
AC cordautomaticallydisconnectstheinternal
battery.
Operationoninternalbattery(option)
Install thebatterypackintheoscilloscopeaccoring
tothefollowingsequence(refertothediagramon
therearofthe case):
*OpenthepackageofthebatterypackBP-7(op-
tion)andchecktomakesurethatitcontainstwo
6V leadbatteriesandconnecting leads.
* Place theoscilloscopewiththeupsidedown,
removethe4 screws on both sides usinga
screwdriver. Holdthecordreelandpullitout.
The battery case coverwillberemoved.
* Release theleadfromthecordclamperandthen
removethescrew(4x 40mm)asshowninthe
diagram.
*Connectthe2 batteriesin series usingthecon-
necting leads, thenconnecttheleads(redand
black) oftheoscilloscopetothebatteries.Make
sure thattheredleadisconnectedto"+"and
theblackleadto" —"side.
*Afterthebatterieshavebeenconnected,insert
thebattery case fromtherearandreplacethe
battery case cover.Thebatteryleadsshouldbe
arranged ontopofthebatteriessothattheyare
notcaughtbetweenthebatteriesandthebattery
case.
*Tightenthe4 screws fromeachsideofthe case
and thescrew(4x 40mm)fromtherearofthe
case.
Now,theoscilloscopeisreadyforoperation. Refer
totheinstructionsinthepreviousparagraph "Con-
trolson Panels". Withtheinternalbattery,theos-
cilloscope canbeoperatedformorethan2 hours,
althoughthisdependsontheconditionofthe
battery.
When thebatteryvoltagefallsdownto10Vduring
operation,theprotectioncircuitisactivatedtoshut
offthebatterycircuit.Inthis case, thepowerlamp
goes offindicatingthatthebatteryisprotected
against over-discharge.Whenthishappens,the
batteryshouldberechargedfullyandimmediately,
(refer toitem"BatteryCharging")
The powerlampwillstartblinkingtoindicate
batteryvoltagedrop10minutesbeforetheprotec-
tion circuitoperates.
OperationonexternalDC(11~ 15.5V)
Connect a DCpowercordfromDC12Vreceptacle
(31) toa nominal12voltDCpowersource(11to
15.5 VDC),suchasa vehiclecigarettelighter.
Observe properpolarity;theoscilloscopeis
protectedagainstreversepolaritydamage,butwill
notoperateifpolarityis reversed.
Turn on POWER/INTEN control(14).
POWER indicator(12)shouldglow,andthescope
is readyforuse.
If CHARGE indicator(13)glows,thebatteriesare
chargingtheindicatorgoesoffwhenthebatteries
are fullycharged.
BATTERY CHARGING
To chargetheinternalbattery,connecttheACline
cordtoACoutlet.Thebatteryischarged
regardless ofthepositionofthepowerswitch.
When batterychargeisstarted,the CHARGE lamp
will light. Withthepowerswitchsetto OFF, the
batteryisfullychargedinabout16hours.Withthe
switch settoON,thebatteryischargedinabout
28 hours;theoscilloscopecanbeusedwhilethe
batteryisbeingcharged.Theexternalpowercon-
8

nectorplugmustbedisconnectedwhilethebattery
is beingcharged.
Whenthebatteryisalmostfullycharged,the
CHARGE lampbecomesdimandfinallygoesoff.
Continuechargingforabout2 hours,thenthe
batterywillhavebeenfullycharged.
MOUNTINGOFHOOD
The suppliedhoodcanbemountedontheos-
cilloscopeasshowninFig.4.
APPLICATIONS
DUAL-TRACE APPLICATIONS
Introduction:
The mostobviousandyetthemostusefulfeature
ofthedual-traceoscilloscopeisthatithasthe
capabilityforsimultaneouslyviewingtwo
waveforms thatarefrequency-orphase-related,or
thathavea commonsynchronizingvoltage,suchas
in digital circuitry.Simultaneousviewingof input
andits output isaninbaluableaidtothecircuit
designerortherepairman. Several possible
applicationsofthedual-traceoscilloscopewillbe
reviewed indetailtofamiliarizetheuserfurtherin
thebasicoperationofthisoscilloscope.
Frequency DividerWaveformsViewing:
Fig. 5 illustratesthewaveforminvolvedina basic
divide-by-twocircuit.Fig.A indicatesthe
reference orclockpulsetrain.Fig.B andFig.C in-
dicatethepossibleoutputsofthedivide-by-twocir-
cuitry.Fig.5 alsoindicatesthesettingsofspecific
oscilloscopecontrolsforviewingthesewaveforms.
In addition tothesebasiccontrolsettings,the
TRIGGERING LEVEL control,aswellasthe
Channel 1 andChannel2 verticalpositioncontrols
shouldbesetasrequiredtoproducesuitabledis-
plays. InthedrawingofFig.5 thewaveform
levels of2 divareindicated.Ifexactvoltage
measurements ofChannel1 andChannel2 are
desired, theChannel1 andChannel2 VARIABLE
controlsmustbeplacedintheCALposition.The
Channel 2 waveformmaybeeitherthatindicated
inFig.5BorFig.5C.InFig.5C,thedivide-by-
two output waveformisshownforthe case where
the output circuitryrespondstonegative-going
Fig. 5 Waveformsindivide-by-twocircuit.
9
HOOD
BEZEL
INSERT CLAWS INTO
4 HOLES
Fig. 4 MountingofHood
CH 1
A. REFERENCE FREQUENCY PULSE
TRAIN(1000 PULSES PERSECOND)
LEADING EDGES MAYNOTBE
VISIBLE AT FAST SWEEP RATES
CH 2
B. DIVIDE-BY-TWOOUTPUTSYNCHRONIZEDTO
LEADING EDGE OF REFERENCE PULSE
CH 2
C. DIVIDE-BY-TWOOUTPUTSYNCHRONIZEDTO
TRAILING EDGE OF REFERENCE PULSE

waveform.Inthis case, the output waveformis
shifted with respecttotheleadingedgeofthe
reference frequencypulsebya timeintervalcor-
respondingtothepulsewidth.
Divide-by-8CircuitWaveforms:
Fig. 6 indicateswaveformrelationshipsfora basic
divide-by-eightcircuit.Theoscilloscopesettings
are identicaltothoseusedinFig.5.The
reference frequencyofFig.6Aissuppliedtothe
Channel 1 input. Fig.6Bindicatestheidealtime
relationshipbetweenthe input pulsesandthe out-
putpulse.
Inanapplicationwherethelogiccircuitryis
operatingatornearitsmaximumdesignfrequency,
theaccumulatedrisetimeeffectsofthecon-
secutive stagesproducea built-in timepropagation
delay whichcanbesignificantina criticalcircuit
andmustbecompensatedfor.Fig.6Cindicates
thepossibletimedelaywhichmaybeintroduced
into a frequencydividercircuit.Byuseofthedual-
trace oscilloscope,the input and output waveforms
can besuperimposed(ADDorSUB)todetermine
theexactamountofpropagationdelaythatoccurs.
A. REFERENCE FREQUENCY PULSE TRAIN
(1000 PULSES PER SECOND)
B. IDEAL DIVIDEBYEIGHTOUTPUT
PropagationDelayTimeMeasurement:
Anexampleofpropagationdealyina divide-by-
eightcircuitwasgiveninthepreviousparagraph.
Significantpropagationdelaymayoccurinanycir-
cuit. This oscilloscopehasfeatureswhichsimplify
measurementofpropagationdelay.Fig.7 shows
theresultantwaveformswhenthedual-trace
presentationiscombined into a single-trace
presentationbyselectingtheADDorSUB(CH2
POLARITY PULL INV)positionoftheMODE
switch. IntheADDpositionthetwoinputsare
algebraicallyaddedina single-tracedisplay.
Similarly, intheINV.(pull)positionthetwoinputs
are algebraicallysubtracted.Eitherposition
providesa precisedisplayofthepropagationtime
(Tp). Usingtheproceduregivenforcalibratedtime
measurement (CAL), Tpcanbemeasured.A more
10
precise measurementcanbemeasured.A more
precise measurementcanbeobtainediftheTp por-
tion ofthewaveformisexpandedhorizontally. This
may bedoneby pulling theX5MAGcontrol.It
also maybepossibletoviewthedesired portion of
thewaveformata fastersweep speed.
EXPAND THISPORTION
FOR TIMEMORE PRECISE
MEASUREMENT
DigitalCircuitTimeDelayMeasurement:
Since a dual-traceoscilloscopehasthecapabilityof
comparingthe timing ofonewaveform with
another,itisnecessityindesigning,manufacturing
andservicing digital equipment.In digital equip-
ment,itiscommonfora largernumberofcircuits
tobesynchronized,ortohavea specifictime-
relationshiptoendother.Manyofthecircuitsare
frequencydividersaspreviouslydescribed,but
waveforms are often time-relatedinmanyother
combinations.Inthedynamicstate,someofthe
waveforms changedependinguponthe input or
moreofoperation.Fig.8 showsa typical digital
cuicuitandidentifies several ofthepointsatwhich
waveformmeasurementsareappropriate.Theac-
companyingFig.9 showsthenormalwaveformsto
beexpectedateachofthesepointsandtheirtim-
ingrelationship.Theindividualwaveformshave
limited valueunlesstheir timing relationshiptoone
ormoreoftheotherwaveformsisknowntobecor-
rect.Thedual-traceoscilloscopeallowsthiscom-
parisontobemade.Intypicalfashion,waveform
No.3 wouldbedisplayedonChannel1 and
C. PROPAGATION DELAY INDIVIDEBY
EIGHT CIRCUIT
Fig. 6 Waveformsindivide-by-eightcircuit
Fig. 7 UsingADDorSUBmodesfor
propagationtimemeasurement
CH1
CH2
ADD
SUB

Fig. 8 Typical digital circuitusingseveral time-related waveforms
11

waveformsNo.4 through No.8 andNo.10,would
bedisplayedonChannel2 althoughother timing
comparisonsmaybedesired.
WaveformsNo.11 through No.13wouldprobably
bedisplayedonChannel2 inrelationshipto
waveformNo.8 orNo.4 onChannel1.Inthe
familyoftime-relatedwaveformsshowsinFig.9,
waveformNo.8 orNo.10isanexcellentsync
source forviewingallofthewaveforms;thereis
butone triggering pulseperframe.Forcon-
venience, externalsyncusingwaveformNo.8 or
No.10asthesyncsourcemaybedesiable.
With No.8 orNo.10usedasexternalsyncsource.
any ofthewaveformsmaybedisplayed without
readjustmentofthe TRIGLEVEL control.
WaveformsNo.4 through No.7 shouldnotbeused
as thesyncsourcebecausetheydonotcontaina
triggering pulseatthestartoftheframe.Itwould
notbenecessarytoviewtheentirewaveformsas
showninFig.9 inall cases. Infact,therearemany
timeswhena closerexaminationofa portion ofthe
waveformswouldbeappropriate.Insuch cases, it
is recommended that thesyncremainunchanged
whilethesweepspeedorX5MAG control isused
toexpanedthewaveformdisplay.
1START
3 CLOCK
4DATA SELECT "A"
5DATA SELECT "B"-
6DATA SELECT "C"•
7DATA SELECT "D"
8DATE ENABLE•
9 RUN
12
LINE DRIVER
O.UTPUT'
13
ANYINDIVIDUAL ADDRESS ORFUNCTION
DATABITMAYBEPOSITIVEORNEGATIVE
DEPENDING UPONTHECODEDINPUT
Fig. 9 Familyoftime-relatedwaveforms from typicaldigitalcircuitinFig.8
12
2COUNTER
ENABLE
10ENDFRAME
RESET I
11MULTIPLEXER
OUTPUT

DistortionMeasurement:
An amplifierstage,oranentireamplifier unit, may
betestedfor distortion with thisoscilloscope. This
measurement isespeciallyvariablewhentheslope
ofa waveformmustbefaithfullyreproducedbyan
amplifier.Fig.10showsthetestingofsucha cir-
cuitusinga triangular wave, suchasistypicallyen-
counteredintherecoveredaudio output ofa
limiting circuitwhichprecedesthemodulatorofa
transmitter.Themeasurementmaybemadeusing
any typeofsignal;merelyusethetypeofsignalfor
testingthatisnormallyappliedtotheamplifierdur-
ingnormaloperation.Theprocedurefor distortion
testingisasfollows:
SUB=DISTORTION
ADJUST POSITION CONTROLS TO
SUPERIMPOSE WAVEFORMS DIRECTLY
OVER EACH OTHER
ADJUST TOBOTH
WAVEFORMS ARE
SAME AMPLITUDE
1. Applythetypeofsignalnormallyencountered
intheamplifierundertest.
2. ConnectChannel1 probetothe input ofthe
amplifierandChannel2 probetothe output of
theamplifier.Itispreferableifthetwosignals
are notinvertedinrelationshiptoeachother
butinvertedsignalscanbe used.
3. SetChannel1 andChannel2 DC-GND-AC
switches toAC.
4. SettheMODEswitchto DUAL.
5. Set SYNC SLOPE switchtoINTandadjust
controlsasdescribedinwaveformveiwing
procedureforsynchronizingwaveforms.
6. AdjustCH1andCH2 POSITION controlsto
superimpose thewaveformsdirectlyovereach
other.
7. AdjustCH1andCH2verticalsensitivitycon-
trols (VOLTS/DIV and VARIABLE) sothatthe
waveforms areaslargeaspossible without ex-
ceeding thelimitsofthe scale, andsothat
both waveformsareexactlythesame hight.
8. Now,settheModeswitchtoADDandCH2
Polarity ofINV(ifonewaveformisinvertedin
relationshiptotheother,usetheNOR
position).
Adjustthefineverticalsensitivitycontrol(CH2
VARIABLE) slightlyfortheminimumremain-
ingwaveform.Anywaveformthatremains
equals distortion;ifthetwowaveformsareex-
actly thesameamplitudeandsamewaveform
and thereisnodistortion,thewaveformswill
cancel andtherewillbeonlya straight
horizontallineremainonthe screen.
Gated Rising Circuit(burstcircuit)
Fig. 11showsa burstcircuit.The basic settingsof
controlknobsarethesameasthoseinFig.5.The
waveformA isthereferencewaveformandis
appliedtoCH1 input. Allotherwaveformsare
sampled atCH2andcomparedtothereference
waveforms aresampledatCH2andcomparedto
thereferencewaveformof CH1. Theburstsignal
13
AMP
No.1 AMP
No.2
Fig. 10Distortionmeasurement
Fig. 11Gatedringingcircuitandwaveforms

can beexaminedmorecloselyeitherbyincreasing
thesweep time orby pulling the POSITION
control to obtain 5 timesmagnification.
Delay Line Test:
The dual-tracefeatureoftheoscilloscopealsocan
beusedtodeterminethedelaytimesoftransmis-
siontypedelaylinesaswellasultrasonictype
delaylines.The output ofdelaylinescanbe
observedonCH2whilebeingsynchronized with
the input pulseof CH1. A repetitivetypepulse will
makeitpossibletosynchronizethedisplays.The
intervalbetweenrepetitivepulsesshouldbelarge
comparedtothedelay time tobeinvestigated.In
addition,todeterminingdelaytime,thepulsedis-
tortion inherentinthedelaylinecanbedetermined
byexaminationofthedelaypulseobservedonCH2
waveformdisplay.
Fig. 12demonstratesthetypicaloscilloscopeset-
tingsaswellasthebasictestcircuit.Typical input
and output waveformsareshownontheos-
cilloscopedisplay.A commonapplicationofdelay
linechecksis found incolorTVreceivers.Fig.13
shows theoscilloscopesettingsandtypicalcircuit
connectionstocheckthe"Y"delaylineemployed
inthevideoamplifiersection.The input waveform
and output waveformarecomparedfordelaytime,
usingthehorizontalsyncpulseofthecomposite
videosignalforreference.Theindicateddelayis
approximatelyonemicrosecond.In addition to
determiningthedelaycharacteristicsoftheline,
the output waveformreveralsany distortion that
maybeintroduced from animpedancemismatchor
a greatlyattenuated output resulting from anopen
line.
CH -1
(INPUT PULSE)
CH 2
(OUTPUT PULSE)
PULSE GENERATOR
5000PPS
tjj. sec.
PULSE WIDTH INPUT
ULTRA SONIC DELAY
LINE (5Msec)
OUTPUT
Fig. 12Delaylinemeasurements
VIDEO
AMPLIFIER
•NOTE: SETTINGOF VERTICAL"
tATTENUATORS SHOULDBE
THE SAME,BUTMAYVARY
WIDELY, DEPENDINGONCIRCUIT
TYPE.
TO VIDEOOUTPUT
AMPLIFIER
NOTE: NO ELECTRICAL CONNECTION:
PLACE CLIP ONINSULATIONOF PLATE
CAP LEAD ORIN CLOSE PROXIMITYOF
HORIZONTAL AMPLIFIER TUBE.
14
Fig. 13Checking"Y"delaylineincolortelevisionreceivers
USE 1/10 PROBE
FOR BOTH CHANNELS
TO HORIZONTAL
AMPLIFIER
CH 1 (INPUT)
CH 2 (OUTPUT)
1jLtS DELAY
EXT TRG
ON SIDE
PANEL

Stereo AmplifierServicing:
Anotherconvenientusefordual-traceoscilloscope
is in troubleshooting stereoamplifiers.Ifidentical
amplifiersareusedandthe output ofoneisweak,
distorted orotherwiseabnormal,thedual-traceos-
cilloscopecanbeefficientlyusedtolocalizethe
defectivestate. With anidenticalsignalappliedto
theinputsof both amplifiers,a side-by-sidecom-
parisonof both unitscanbemadebyprogressively
samplingidenticalsignalpointsin both amplifiers.
Whenthedefectiveormalfunctioningstagehas
beenlocatedtheeffectsofwhatever
troubleshooting andrepairmethodsareemployed
can beobservedandanalyzedimmediately.
improvingtheRatioofDesiredtoUndesired
Signals:
Insomeapplications,thedesiredsignalmaybe
riding ona largeundesiredsignalcomponentsuch
as 60Hz.Itispossibletominimizeorforpractical
purposeeliminatetheundesiredcomponent.Fig.
14showstheoscilloscope control settingsforsuch
an application.ThewaveformdisplayofChannel1
indicatesthedesiredsignalandthe dotted linein-
dicates theaverageamplitudevariationcorrespon-
ding toanundesired60Hzcomponent.The
Channel 2 displayindicatesa waveformofequal
amplitudeandidenticalphasetotheaverageofthe
Channel 1 waveform. With theMODEswitchset
toADD,andtheCH2signalinverted,andbyad-
justingtheCH2verticalattenuatorcontrol,the60
Hz componentoftheChannel1 signalcanbe
cancelled bytheChannel2 input andthedesired
waveformcanbeobserved.
ADJUST FORONE
COMPLETE CYCLE
AT 60Hz
"SLOPE +
Amplifier Phase ShiftMeasurements:
Phase measurementscanbemadebyseveral
methodsusingoscilloscope.Typicalapplications
are incircuitsdesignedtoprocedurea specific
shift,andmeasurementofphaseshift distortion in
audioamplifiersandnetworks.
Inallamplifiers,a phaseshiftisalwaysassociated
with a changeinamplituderesponse.Forexample,
atthe—3dBresponse point, a phaseshiftof45°
occurs. Fig.15illustratesa method ofdetermining
amplifierphaseshiftdirectly.Inthis case, the
measurementsarebeingmadeatapproximately
5000 Hz.The input signaltotheaudioamplifieris
used asa referenceandisappliedtotheChannel1
input jack.
The VARIABLE control isadjustedasrequiredto
providea completecycleofthe input waveform
displayedon8 divhorizontally.A waveformheight
of2 divis used. The8 divdisplayrepresents360°
atthedisplayedfrequencyandeachcentimeter
represents 45°ofthewaveform.
The signaldeveloped across the output oftheaudio
amplifierisappliedtotheCH2 input jack.
The verticalattenuatorcontrolsofChannel2 are
adjustedasrequiredtoproducea peak-to-peak
waveformof2 divasshowninFig.15B.The
Channel 2 POSITION control isthenadjustedso
that theChannel2 waveformisdisplayedonthe
same horizontal axis astheChannel1 waveformas
ADJUST AS REQUIRED FOR
COMPLETE CYCLE IN8div
OUTPUT
•LOAD
Fig. 14
Improvingdesired-to-undesiredsignalradio
Fig. 15Measureringamplifierphaseshift
15
SIGNAL
60 Hz
START WITH DUAL
CHANGE TOSUB
AF
SIGNAL
GENERATOR
INPUT
AUDIO
AMPLIFIER

showninFig.15B.Thedistancebetweencor-
respondingpointsonthehorizontal axis forthetwo
waveforms thenrepresentsthephaseshift
betweenthetwowaveforms.Inthis case, thezero
crossover pointsofthetwowaveformsarecom-
pared. Itisshownthata differenceof1 div exists.
This istheninterpretedasa phaseshiftof45°.
Television Servicing:
Manyofthevideoservicingprocedurescanbeper-
formedusingsingle-traceoperation. These are
outlinedlaterintheapplicationssectioncovering
single-traceoperation.Oneoftheseprocedures,
viewingthe VITS (verticalintervaltestsignal),can
beaccomplishedmuchmoreeffectivelyusinga
dual-traceoscilloscope.Asoutlinedinthesingle-
trace applicationssectionandasshowninFig.19
and26,theinformationontheField1 andField2
verticalblankingintervalpulseisdifferent. This is
shownindetailinFig.19.Also,becausetheos-
cilloscopesweepissynchronizedtothevertical
blankingintervalwaveform,theField1 andField2
waveforms aresuperimposed onto eachother.
Withdual-traceoperation,thesignalinformation
oneachblankingpulsecanbeviewedseparately
without overlapping.Fig.18indicatestheos-
cilloscopecontrolsettingforviewingthealternate
VITS.
Mostnetworktelevisionsignalscontain built-in
testsignals (VITS) thatcanbeveryvaluabletoolsin
troubleshootingandservicingvideoequipment.
The VITS canlocalize trouble totheantenna,tuner,
IF orvideosectionsandshowswhenrealignment
may berequired.The VITS signalisbeingusedin
some televisionreceiversforautomaticcolorcor-
rection.
The VITS signalistransmittedduringthevertical
blankinginterval.Onthetelevisionset,theycanbe
seen asa bright whitelineabovethetopofthepic-
ture,whentheverticallinearityorheightisad-
justedtoviewtheverticalblankinginterval.(OnTV
sets with internalretraceblankingcircuits,the
blankingcircuitmustbedisabledtoseethese
signals.)
The transmitted VITS isprecisionsequencesof
specific frequencies,amplitudesandwaveshapes
as showninFig.16.Thetelevisionnetworksuse
theprecisionsignalsforadjustmentandchecking
ofnetworktransmissionequipment,butthetechni-
cian canusethemtoevaluatetelevisionsetperfor-
mance. Thefirstframeof VITS atthe"B"section
(line18)inFig.16begins with a whitereference
16
Fig. 16VITSsignal.Fields1 and2
(MULTI-BURST)
VERTICAL BLANKINGINTERVAL(NO:1 ~ NO.21)
HORIZ. SYNC. PULSE
VERTICAL BLANKINGINTERVAL(NO.263~ NO.282)
(MULTI-BURST)
FIELD I
FIELD 2
FIELD I&2
LINE No.17 No.
18
No.279 No.280
No. 17
No.279 No.
18
No.280

signal, followedbysinewavefrequenciesof0.5
MHz, 1.0MHz,2.0MHz,3.0MHz,4.0MHzand
3.58MHz. This sequenceoffrequenciesiscalled
the"multi-burst".
This multi-burst portion ofthe VITS isthe portion
thatcanbemostvaluabletothetechnician.The
second frameofthe VITS (lines18and280),which
contains thesine-squaredpulse,windowpulseand
the staircase of3.58MHzburstsatprogressively
lightershading,arevaluabletothenetwork,but
have less valuetothetechnician.As seen onthe
television screen, field1 isinterlacedwithfield2 so
thatline17isfollowedbyline279andline18is
followedbyline280.The VITS appearsattheend
oftheverticalblankingintervalandjustbeforethe
firstlineofvideo.
Nowtoanalyzethewaveform.Allfrequenciesof
themulti-burstaretransmittedatthesame level,
butshouldnotbeequallycoupledthroughthe
receiver duetoitsresponsecurve.Fig.28shows
thedesiredresponsefora goodcolortelevision
receiver, identifyingeachfrequencyofthemulti-
burstandshowingthesllowableamountof
attenuationfor each. Rememberthat— 6 dB
equals halfthereferencevoltage(the2.0MHz
modulationshouldbeusedforreference).
To localizetrouble,startbyobservingthe VITS at
thevideodetector. This willlocalizetroubletoa
point eitherbeforeorafterthedetector.Ifthe
multi-burstisnormalatthedetector,checkthe
VITS onotherchannels.Ifsomechannelslook
okay butothersdonot,youprobablyhavetuneror
antenna-system troubles.Don'toverlookthe
IF
AMP
VIDEO
DETECTOR
TELEVISION SET
VIDEO
AMP
SOUND
IF
COLOR
IF
Fig. 18Set-upforviewingfields1 and2 ofVITSinformation
17
RESPONSE-dB
FREQUENCY—MHz
Fig. 17
Color TVIFamplifierresponsecurve
chance oftheantennasystemcausing"holes"or
tilted responseonsomechannels.Ifthe VITS is
abnormalatthevideodetectoronall channels, the
troubleisprobablyintheIFamplifier stages.
As anotherexample,letus assume thatwehavea
set onthebenchwitha verypoorpicture.Ouros-
cilloscope showsthe VITS atthevideodetectorto
beaboutnormalexceptthattheburstat2.0MHz
is lowcomparedtotheburstsoneitherside. This
suggests anIFtrapisdetuned into thepassband,
choppingoutfrequenciesabout2 MHzbelowthe
picturecarrierfrequency.Switchtoanother
channels, carrying VITS. Ifthesame thing is seen.
VIDEO
VERTICAL SYNC
PULSE
VERTICAL BLANKING
VIDEO
AMP
PICTURE
TUBE

thenourreasoningis right, andtheIFamplifier
requiresrealignment.Ifthepoorresponseat2
MHz
thetuner input ismisadjusted,causinga bite on
onlyonechannel.Othertrapsatthe input ofthe
set couldsimilarlybemisadjustedorfaulty.
Ifthe VITS responseatthedetector output isnor-
malforallchannels,the tourble willbeinthevideo
amplifier.Lookforopenpeakingcoils,off-value
resistors, solderbridges across foil patterns,etc.
Withdual-traceoscilloscopeoperation,thesignal
informationoneachverticalblankingintervalcan
beviewedseparately without traceoverlapping,
althoughtheinformationalternates with each
field.Fig.18indicatestheoscilloscopecontrol
settingforviewingthealternateverticalblanking
intervals.
1. ThecolorTVreceiveronwhichtheverticalin-
tervalinformationistobeviewedmustbeset
toa stationtransmittinga colorbroadcast.
2. ThecontrolsettingsofFig.18arethesere-
quiredtoobtaina 2-Fieldverticaldisplayon
CH1.
3. WiththeoscilloscopeandtheTVreceiver
operating,connecttheCH1probe(setto
10:1) tovideodetectortest point.
4. Setthe SYNC and SLOPE switchesasfollows:
A. Ifthe sync andblankingpulsesofthe
observed videosignalarepositive,usethe
TV, + positions.
B. Ifthe sync andblankingpulsesare
negative,usetheTV,— positions.
5. Adjustthesweeptime VARIABLE controlso
that2 verticalfieldsaredisplayedontheos-
cilloscope screen.
6. ConnecttheCH2probe(setto10:1)tothe
videodetectortest point.
7. SettheMODEswitchtoDUALposition.
8. Place thesweeptime VARIABLE intheCAL
position.
9. Setthe SWEEP TIME/DIV controltothe0.1
ms position. This expandsthedisplayby
increasing thesweepspeed.The VITS in-
formationwillappeartowardthe right hand
portion oftheexpandedwaveformdisplays.
The waveforminformationoneachtracemay
appear asshowninFig.16. Because thereis
noprovisionforsynchronizingtheoscilloscope
displaytoeitherofthetwofieldswhich
comprisea completeverticalframe,ifcannot
bepredictedwhichfielddisplaywillappearon
theCH 1 orCH2display.
10. Pullthe<> POSITION controloutwardtoob-
tainanadditionalX5magnification.Rotate
18
thecontrolina counterclockwisedirection
movingthetracestothe left untiltheexpand-
edinformationappearsasshowninFig.16.
Because ofthelow repetition rateandthehigh
sweep speedcombination,thebrightnesslevel
ofthesignaldisplayswillbereduced.
11. OncetheCH 1 andCH2displayshavebeen
identifiedasbeingeitherField1 orField2
VITS intormation,theprobecorrespondingto
thewaveformdisplaywhichistobeusedfor
signal-tracingandtroubleshootingcanbeused
andtheremainingprobeshouldbe left atthe
videodetectortest point toinsurethatthe
sync signalisnotinterrupted.Ifthe sync
signal isinterrupted,thewaveformdisplays
may bereversedbecause,aspreviouslyex-
plained,thereisnoprovisionintheos-
cilloscopetoidentifyeitherofthetwovertical
fieldswhichcomprisea completeframe.
SINGLE-CHANNEL APPLICATIONS
introduction:
In addition tothedual-traceapplicationspreviously
outlined,thereare,ofcourse,manyservicingand
laboratoryapplicationswhereonlysingle-traceor
single-channel operationoftheoscilloscopeisre-
quired.BysettingtheMODEswitchtoCH2and
usingtheCH2amplifier,manyflexibleoperations
willbeachieved;and,inaddition,byplacingthe
CH2 switchto PULL INVpositionwhatever
waveformisobtainedcanbeinvertedinpolarityif
desired bytheoperator.
Television Servicing:
A triggeredsweeposcilloscopeisadvantageousin
servicing andaligningtelevisionreceivers. This os-
cilloscopealsoincludesinaddition,severalfeatures
thatwereincorporatedtomaketelevisionservicing
easier andmorecomprehensive. These featurein-
clude:
*Withthe SYNC switchsettoTVposition,the
SWEEP TIME/DIV controlautomaticallyselects
theTVvertical sync atsweepspeedsappropriate
forviewingframesandhorizontal sync atsweep
speeds appropriateforviewinglines.
•Widebandwidthforhighresolutionvideoand
highspeedpulsepresentation.
Single-trace OperationandPeak-to-peak
VoltageReadings:
For generaltroubleshootingandisolationof
troublesinalmostanyelectronicequipment,the
oscilloscopeisanindispensableinstrument.It
providesa visualdisplayofabsenceorpresenceof

normalsignals. This method (signal-tracing)may
beusedtotracea signalbymeasuringseveral
pointsinthesignalpath.Asmeasurements
proceedalongthesignalpath,a point maybe
found wherethesignaldisappears.Whenthis
happens, thesourceof trouble hasbeenlocated.
However,theoscilloscopeshowsmuchmorethan
themerepresenceorabsenceofsignal.Itprovides
a peak-to-peakvoltagemeasurement.The
schematic diagramoraccompanyingservicedata
ontheequipmentbeingserviedusuallyincludes
waveformpictures.Therewaveformpicturesin-
cludetherequiredsweep time andthenormal
peak-to-peakvoltage.Comparethepeak-to-peak
voltagereadingsandwaveshapeontheos-
cilloscope with thoseshownonthewaveformpic-
tures. Anyabnormalreadingsshouldbe followed
byadditionalreadingsinthesuspectedcircuitsun-
tilthe trouble isisolatedtoassmallan area as
possible.
CompositeVideoWaveformAnalysis
Probablythemost important waveformintelevi-
sionandvideoservicingisthecompositewaveform
consistingofthevideosignal,theblankingpedestal
signals andthe sync pulses.Fig.19andFig.20
showtypicaloscilloscopetraceswhenobserving
compositevideosignalssynchronized with horizon-
tal sync pulsesandvertical sync pulses.Composite
videosignalscanbeobservedatvariousstagesof
thetelevisionreceivertodeterminewhethercir-
cuitsare performing normally.Knowledgeof
waveformmakeup,theappearanceofa normal
waveform,andthe cause ofvariousabnormal
waveformshelpthetechnicianlocateandcorrect
manyproblems.Thetechnicianshouldstudysuch
waveformsina televisionreceiverknowntobein
good operatingcondition, nothing thewaveformat
varous pointsinthevideoamplifier.Tosetupthe
oscilloscopeforviewingcompositevideo
waveforms,usethe following procedures:
BURST
VIDEO
\
IF AMP
VIDEO
DETECTOR
PICTURE]
TUBE;
TELEVISION SET SOUNDIF
COLOR IF
Fig. 19Set-upforviewinghorizontalfieldsofcompositevideosignal
VIDEO
IF AMP
VIDEO
DETECTOR
TELEVISION SET
VIDEO
AMP
SOUNDIF
VIDEO
AMP
COLOR IF
PICTURE i
TUBEJ
Fig. 20Set-upforviewingverticalfieldsofcompositevideosignal
19
HORIZONTAL
SYNC PULSE
HORIZONTALBLANKMNG
PULSE •=
VIDEO
AMP
VIDEO
AMP
VERTICAL SYNC
PULSE
VERTICAL BLANKING