29
5.2.4Frequencymeasurement
620R/640R/650R
corner.
hasbuiltinfrequencyaccount,itcanreadfrequencydirectly.Thevalueoffrequencydisplayedinthe
bottom-right
1.Incaseofconfusedresults,setTRIGALT(27)atoutposition.
2.SingleChannel:
SettheVertMODE(14)toCH1orCH2,thensetTriggersource(23)totherelatedposition.TuningTriggerLevelknobuntil
onestableandsynchronizedwaveformdisplayedonthescreen,thenthefrequencyvalueofflorf2thatappearedonthe
bottomofrightcorner.
3.Doublechannel:
SettheVertMODE(14)toDUAL,thensetTriggerSource(23)torelatedposition,TuningTriggerLevelknobuntilreceive
onestableandsynchronizedwaveform,thenthevalueofflorf2appearedonthebottomofrightcorneristhemeasured
frequency.
4.Line
SetTriggerSource(23)toLINE,thefrequencywillrepresentasfL.
5.ExternalSynchronizesignal:
SetTriggerSource(23)toEXT,thefrequencywillrepresentasfE.
6.Frequencymeasurementrange:
2OHz~20MHz(5620NF/620BF/620R)
NOTE:Asthemagneticfieldeffecting,CRTreadoutcharactersmaymoveoutofscreen,inthisstationthereadoutposition
adjustmentisrequired.
47V.VARVerticaladjusting;
46H.VARHorizontaladjusting
Adjustabovetwopotentiometersmovethereadoutcharacterstothescreencenter.Thesetwopotentiometerlocatedonthe
CRTreadoutboard.
āā
frequency,
2OHz~40MHz(640BF/650BF/640R/650R)
30
6.MAINTENANCE
Thefollowinginstructionsareforusebyqualifiedpersonnelonly.Toavoidelectricalshock,donotperformanyservicing
otherthanintheoperatinginstructionsunlessyouarequalifiedtodoso.
6.1FuseReplacement
Ifthefuseblows,thepowerlampindicatorswillnotlightandtheoscilloscopewillnotoperate.Thefuseshouldnotnormally
openunlessaproblemhasdevelopedintheunit.Trytodetermineandcorrectthecauseoftheblownfuse.Therep1aceonlywithafuseofthe
correctratingandtype(seepage6)
Thefuseislocatedontherearpanel(seefig.4-3).
6.2Cleaning
Tocleantheoscilloscope,useasoftclothdampenedinasolutionofmilddetergentandwater.Donotspraycleanerdirectlyon
totheoscilloscopebecauseitmayleakintothecabinetandcausedamage.
Donotusechemicalscontainingbenzine,benzene,toluene,xylene,acetone,orsimilarsolvents.
Donotuseabrasivecleanersonanyportionoftheoscilloscope.
WARNING
WARNING
.Forcontinuedfireprotection.Replacefuseonlywith250Vfuseof
thespecifiedtypeandrating,anddisconnectpowercordbeforereplacingfuse.
!