Specifications

Section-3 Operation
October 17, 2013
3‐68
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WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
Caution
CHANGING THE SOUND CARRIER AND CARRIER LEVEL SETTINGS ON THE
MONO CARRIER SETUP SCREEN WILL CAUSE THE TRANSMITTER TO
MUTE TEMPORARILY.
Figure 3-64 LPU Analog Setup Screen 3 Mono
Table3‐61XmtrHome>ExciterHome>Setup>AnalogModulator(screen3Mono)
Field Explanation
MonoCarr
ierSetupSubWindow (Screen3)
SoundCarri
er1
ChoicesareOfforOn.
Offisus
edtoturnthesoundcarrierofffortestpurposes.
Carrier1Level
Valueent
eredin‐dB.
RepresentstheamplitudeadjustmentofthesoundcarrierlevelindBrelativetopeaksyncofthe
visioncarrierrange.
Procedure:
Step1:Di
splaythechannelspectrumonaspectrumanalyzer.
Step2:Setvisu
alcarrierpeakofsyncreferencelevelto0dBm.
Step3:Adj
usttheCarrier1Level(soundcarrierlevel)toachievethedesiredpeakvisualto
soundcarrierratio.
DeviationLimiter
Threshold
Choicesar
eOff,60kHz,90kHz,or120kHz.
Thisfun
ctionwilllimitthesoundcarrierfrequencydeviationtothevalueselectedandprevent
soundcarrieroverdeviation.
AFGainSubWindow(Screen3)
AFSN
D1
Valueent
eredindB.
Thevalueenteredinthiswindow(rangeof‐9.9to+6dB)isintendedtochangetheAFSound1
inputgainsothattheadjustedsignallevelwillbe0dBm.
Iftheactualinputlevelisotherthan0dBm,theAFSND1(Sound1gain)mustbeadjustedto
changetheinputlevelto0dB.Whentheinputlevelhasbeencorrectlyset,thedeviationwillbe
+/‐50kHzforPALand+/‐25kHzforBTSC.
Forexa
mple,iftheactualinputlevelis‐6dBm,setAFSND1(gain)to+6dB,toproducecorrect
audiodeviation.
DetectorDec
ay
Choicesar
eFastorSlow.
ThisdefinesthespeedatwhichtheDeviationSoundCarrier1indicationreturnstozero.
Preemphasis
Choicesar
eOff,50us,or75us.
Thisch
oicesetsthepreemphasisofthemodulationofthemonauralsoundcarrier.