Matrix 620B - 4.7 TIME;DIV Control; 4.8 Sweep Magnification; 4.9 X-Y Operation

(4)FunctionofTRIGALTswitch:
TheTRIGALTswitchisusedtoselectalternatetriggeringandalternatedisplaywhentheDUAL-traceVERTMODEis
Selected(theswitchhasoneffectintheCH1,CH2,orADDmodes).Inthealternatetriggeringmode(whendual-traceoperation
isselected),thetriggersourcealternatesbetweenchannellandchannel2witheachsweep.Thisisconvenientforchecking
amplitudes,waveshape,orwaveformperiodmeasurements,andevenpermitssimultaneousobservationoftwowaveformswhich
arenotrelatedinfrequencyorperiod.However,thissettingisnotsuitableforphaseortimingcomparisonmeasurements.Forsuch
measurements,bothtracesmustbetriggeredbythesamesyncsignal.
WhentheCHOPandtheTRIGALTswitchesarebothengagedduringdual-traceoperation,synchronizationofthedisplayisnot
possiblebecausethechoppingsignalbecomesthetrigger.UsetheALTmodebyitself,orselectCH1orCH2astriggersource.
SettheTIME/DIVcontroltodisplaythedesirednumberofcyclesofthewaveform.Iftherearetoomanycyclesdisplayedforgood
resolution,switchtoafastersweepspeed.Ifonlyalineisdisplayed,tryaslowersweepspeed.Whenthesweepspeedisfasterthan
thewaveformbeingobserved,onlypartofitwillbedisplayed,whichmayappearasastraightlineforasquarewaveorpulse
waveform.
Whenacertainpartofthedisplayedwaveformisneededtobeexpandedtimewise,afaster
sweepspeedmaybeused.However,iftherequiredportionisapartfromthestartingpoint
ofthesweep,therequiredportionmayrunofftheCRTscreen.Insuchacase,pushin
thex10MAGbutton.Whenthishasbeendone,thedisplayedwaveformwillbe
expanded10timestotherightandleftwiththecenterofscreenasthecenterof
expansion.Thesweeptimeduringthemagnificationoperationisasfollows:
(ValueindicatedbyTIME/DIVswitchk1/10
Thus,theunmagnifiedmaximumsweepspeed(lusec/DIV)canbeincreased
withthemagnificationasfollows:
lusec/DIVx1/10=100nsec/DIV
4.7TIME/DIVControl
4.8SweepMagniftcation
10xmagnification
Anypartcanbecoveredby
meansofPOSITIONcontrol
Figure4-8
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4.9X-YOperation
SettheTIME/divswitchtoX-Yposition.Thentheinstrumentworksasan
X-Yoscilloscope.Eachinputisappliedtotheinstrumentasfollows.
X-axissignal(horizontalaxissignal):CH1INPUT
Y-axissignal(verticalaxissignal):CH2INPUT.
Note:WhenhighfrequencysignalsaredisplayedintheX-Yoperation,pay
attentiontothefrequencybandwidthsandphasedifferencebetweenXandY-axis.
X-Yoperationpermitstheoscilloscopetoperformmanymeasurementsnotpossiblewithconventionalsweepoperation.The
CRTdisplaybecomesanelectronicgraphoftwoinstantaneousvoltages.Thedisplaymaybeadirectcomparisonofthetwo
voltagessuchasavectorscopedisplayofvideocolorbarpatterns.However,theX-Ymodecanbeusedtographalmostany
dynamiccharacteristicifatransducerisuesdtochangethecharacteristic(frequency,temperature,velocity,etc.)intoavoltage.
Onecommonapplicationisfrequencyresponsemeasurements,wheretheY-axiscorrespondstosignalamplitudeandtheX-axis
correspondstofrequency.
1.SettheTIME/divcontroltotheX-Yposition(fullycounterclockwise).Inthismode,channel1becomestheX-axis
inputandchannel2becomestheY-axisinput.
2.TheXandYpositionsarenowadjustedusingthehorizontalPOSITIONandC2POSITIONcontrolsH
respectively.
3.Adjusttheamountofvertical(Y-axis)deflectionwiththeCH2VOLTS/DIVandVARcontrols.
4.Ajusttheamountofhorizontal(X-axis)deflectionwiththeCHlVOLTS/DIVandVARcontrols.d
Yaxis(CH2)
Xaxis
(CH1)
Figure4-9