Specifications

Maxiva UAX
October 17, 2013
5‐27
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
STEP 16 LOWPOWERCALIBRATION(10%)‐UsingtheUParrows(GUI)orPowerRaise
(frontpanelbuttons)ontheLPU,increasethetransmitterpoweruntilthe
desiredlevelisindicatedonthepowermeter.RefertoAdjustOutputPower
subwindowinFigure5‐13onpage5‐23.
a.
Thesmalluparrowboxisforfineincrementsandthelargeboxisforlargersteps.
Itmayalsobenecessarytoutilizethedownarrowboxes.Severaladjustmentswill
benecessary.
b. Maintainthedesiredlevelforseveralminutestoallowforthermalsettlingofthe
poweramplifierstages.
c. PresstheSavebuttontostorethecali brationsettingtomemory.
STEP 17
HIGHPOWERCALIBRATION(100%)‐UsingtheUParrows(GUI)orPower
Raise(frontpanel)raisethepowerofthetransmitteruntilthedesiredlevel
isindicatedonthepowermeter.
a.
Thesmalluparrowboxisforfineincrementsandthelargeboxisforlargersteps.
Itmayalsobenecessarytoutilizethedownarrowboxes.Severaladjustmentswill
benecessary.
b. Maintainthedesiredlevelforseveralminutestoallowforthermalsettlingofthe
PA’s.Verifysyncisatproperlevel.
c. PresstheSavebuttontostorethecali brationsettingtomemory.
STEP 18
Press“CalibrationComplete”tofinishandexitthecalibrationprocedure.If
youdonotperformthisstep,thecalibrationwillnotbeaccepted.
STEP 19 Proce dur ecomplete.
5.6.2.3 CalibrationErrors
If,uponcompletionofthecalibrationsequence,them essage’CalibrationError’isdisplayed,repeatthe procedure
andnotethedisplayeddetectorADCvalue.Ifyouareabletoobtainthespecifiedpowerlevelsasindicatedonyour
meter,buttheADCisindicatingnear‐zerovalues,oriftheADCvalueatthehi
ghpointequals(orislessthan)the
valueatthelowpoint,thesystemwilldiscardthecalibration.Themostlikelycauseofthisisamissingorincorrectly
connectedforwardsampletotheLPU.Pleaseensurethesampleisproperlyconnected:thetwosamplecablesare
labeledFWDandRFLDontheirhea
tshrinktubing.
Ifan
yPAsarefaultedduringthecalibration,thesystemwillconsideritinvalidanddiscardit.ReplaceanyfaultyPAs
andrepeatthecalibration.
5.6.3 AnalogReflectedCalibration
Systemreflectedpoweriscalibratedoverarangecorrespondingto30dBto10dBreturnloss(1.05:1to2:1VSWR)
relativetofullsystemforwardoutput.Thesystempre‐filterdirectionalcouplerreflectedportsampleroutesthrough
anat tenuatorpad,cables,andasplitter(inthecaseofadualLPUsystem)totheref
lectedinput(s)oftheLPU(s).The
attenuatorpadvalueisselectedpersystemsuchthatafterfactoringincouplingvalue,pad,cableandsplitterlosses,
thesampleintotheLPU(s)willbeapproximately0dBmwitha10dBreturnloss,and‐20dBmwitha30dBreturnloss,
relativetofullsy
stemoutputpower.
Recallfr
omtheforwardpowercalprocedurethattheLPUFWDsampleinputisalsoapproximately0dBmatfull
systemoutputpower.ThiswasbydesigntoallowtheFWDsampletobeusedasaconvenientsignalsourcefor
reflectedcalibration.
Inge
neral,thecalibrationisperformedbyconnectingapowermetertotheforwardcouplerusedinthesystem
forwardcali brationandthenraisingthesystemoutputtofullpower(thevaluewillbeindicatedonthecalibration
screen,itisthesameasthehighcalibrationpointintheforwardc
alibrationasindicatedonthemeter.Theuserwill
thenremovetheRFLDsampleinputcablefromtheactiveLPUandconnecttheFWDsampleinitsplace,througha
20dBpadforthelowpoint,anddirectlyforthehighpoint,providingtheapproximately‐20dBmand0dBmlevels,
respectively.