Specifications

Maxiva UAX
October 17, 2013
1‐7
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
TheLPUusesRTAC™(RealTimeAdaptiveCorrection)toperformpre‐correctionsfornon‐lineardistortionsoccurring
inthetransmitterRFpoweramplifiersandforlineardistortionsoccurringinthehighpowermaskfilter.Lowpower
RFsamplesfromvariousstagesofthetransmitterarerequiredbytheRTACcircuitstodet
erminetheproper
precorrectioncurvestoapply.
TheLP
UmodulatorsectionRFoutputcanbesettoanyUHFchannelandmaybeadjustedtoanylevelupto100mW
averagepowerwhenoperatedinthedigitalmodeandupto200mWpeakofsyncintheanalogmode.TheRFpower
leveladjustmentfortheentiretransmittersyste
misviaavariablegaincontrolcircuitlocatedintheupconverter
portionoftheLPUmodulatorsection.
1.5.1.3 LPUAmplifierSection
ThelowlevelRFsignalfromtheLPUmodulatorsectionispassedviaanexternalcoaxialjumperontherearpanelto
theLPUamplifiersectioninthelowerhalfoftheLPUchassis.
LPUa
mplifiersectionsareavailableintwoconfigurations.Oneconfigurationcontainsasinglepowersupply(PS)and
poweramplifier(PA)module.ThedualPALPU isusedtodrivepoweramplifierblocks(PABs)orasastandalone
transmitterwithoutputpowerofupto100W(digitalmodulation).
LPUPAmodule
shaveoneRFamplifierpalletthatoperateseitherinseries(10Wmoduleonly)orparalleltoprovide
enoughgaintoboosttheoutputsignaltoapproximately10W‐100Wdependingonconfiguration.
TheRFa
mplifierpalletsoperateon50VDCsuppliedbythePSmodules.
Therea
rpaneloftheLPU amplifiercanremovedtoallowamplifiersection50Vfanreplacementwithoutremoving
theLPUchassisfromtheequipmentrack.TheLPUtopcovermustberemovedtochangethetwo12Vfansmounted
inthefrontpartoftheunit.
1.5.2 PowerAmplifierBlock(PAB)
Figure 1-5 PAB (Power Amplifier Block)