Rigol DS6104 - Page 4

RIGOL TECHNOLOGIES USA INC
877-4-RIGOL-1 How-To Guide
info@rigol.com
www.rigolna.com
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TheFFTcanbedisplayedfullscreenwiththechannelaswellbyadjusting
theWINDOWsetting.How ever,youliketoviewittakenoticeofthe
separateVERT/divandHORIZ/divsettingsshowninpurple.Youcanadjust
thesebypushingtheMATHbuttonandthenusingthehorizontaland
verticalscaleknobs.IftheFFTisn’tshownonthescreen,movetheVERTICAL
positionknobuntilyouseethezeropointandthenthesignal.
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 TherearetwooptionsforverticalunitsontheFFT:mVrmsand
dBVrms.Whenlookingtoviewsmallsignalsalongwithmuchlargersignals
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dBVrmsisbeneficialbecauseitprovidesalogscale.Forthosenotusedto
logarithmicscalinglookatthescreenshotabove.Inthesplitscreenmode
shownthereare8verticaldivisions dedicatedtotheFFT.Herearethevalues
atthetopofeachdivisiongiventhe200mVrms/div
settingandtheposition
ofthezeromarkerontheleftatthetopofthebottomdivision:

DivisionsdownfromtopofFFT
screen
Valueattopofthatdivision
0(topofpurpledisplay) 1.4Vrms
1 1.2Vrms
2 1Vrms
3 800mVrms
4 600mVrms
5 400mVrms
6 200mVrms
7 0mVrms
8(verybottomofthescreen) ‐200(negativenumbersarenotused
byamVrmsscale)
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So,inthismodetheFFThasabout1.4Vrmsoftotalrangecapability.Youcan
changethesensitivity,butifyouwantedtoseea10Vrmsfundamentalanda
10mVrmsharmonicatthesametimeitisn’tpossibleonalinearscale.