Specifications

Maxiva UAX
October 17, 2013
4‐15
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
4.4.2 MultiplexedDevices
TheAmpControlgathersdatafromthedifferentdeviceswithinthetransmitter.Thedevicesthatarereadarethe
PowerAmplifiers,FanInterfaces,andCoupler/Detectors.Thedataisgatheredovertheanaloganddigitalbusses
whichconsistoffourlineseach.Thebussesaremultiplexedusingeightchipselectinputs.Athir
dbus,LEDbus,is
utilizedwithinthePABinconjunctionwiththeeighthchipselecttocontroltheLEDsonthefrontofthePAB’s.The
followingchartshowsinformationreportedonthebusses.
4.5 PowerAmplifierBlock(PAB)
Dependingonthetransmittedpowerlevel,theUAXtransmittermaybeequippedwithoneormoreexternalpower
amplifierblocks(PAB).SeeTable1‐3onpa
ge1‐9foralistingonthenumberofPAblocksasafunctionoftransmitter
model.Asofth
isprinting,externalPABsareavailablein2‐PA,&4‐PAversions.
4.5.1 PowerAmplifierModule
Thepoweramplifier(PA)modulefeaturestwobroadband(470‐860MHz)push‐pullMOSFETRFpoweramplifier
attachedtoaheatsink.ThemoduleoperatesinclassABmodewitha50Vdrainvoltagetodevelopapproximately
17‐19dBgainat180Waveragepowerout,depen dingonmodulationformat.Themodulesar
ehot‐pluggableand
requirenouseradjustments.
Thetw
oFETsareattachedtocopperheatspreadersandaffixedtoacircuitboardtoformanamplifierpallet.Inthe
caseofaFETfailureinthefield,theentirepalletcanbeeasilyreplacedwithapre‐tunedpalletfromasparesdep ot
orHarrisServiceCenter.Thisel
iminatestheneedforFETtuning&optimizationinthefieldafteraFETreplacement.
EachPAmodul
eplugsintoaPAbackplanecard.ThePAbackplaneprovideson/offfunctionalityandalarmschecking
fortemperatureandcurrentoverloads
PAmodul
eshavetwoconfigurations:
• UAX‐10WPAmodule:TheoutputofoneFETser vesastheinputforthesecondFET.This
typeofmoduleisonlyusedina10Wtransmittersystem.
• UAX‐standardPAmodule.ThetwoFETsoperateinparallel.Thisstandardmoduleisusedin
allmodelUAXtransmittersandLPUsex ceptforthe10Wmodel.
Thetw
otypesofPAmodulesdescribedabovedifferphysicallyandarenotinterchangeable.
4.5.2 PowerSupplyModule
Thepowersupply(PS)module isa1200W48Vpowersupplywitha.98powerfactorandmainsinputrangeof90‐
264V.Ithasanadjustableoutputrangeof43‐53V,andistypicallyadjustedto48VintheUAXtransmitter.