Specifications

Section-5 Maintenance
October 17, 2013
5‐64
Copyright©2013,HarrisBroadcast
WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
STEP 7 Replacethefrontpanelandfingertightenthefasteners.Donotusea
screwdrivertotightenthethumbscrews.
STEP 8 Endofprocedure.
5.10.3 OperationWithInoperativeModules
ThePABPAmodulerejectloads,locatedinsidethePABmodulecombiner,aresizedwithenoughmargintoallow
operationunderanyimbalanceconditionthatmaybeencountered.AslongasonePABmoduleandonePSmodule
areinstalledandoperationalthepowerblockwillcontinuetoproduceRFpowerbu
tatreducedlevels(theoutput
leveldependsonhowmanyPABmodulesareremoved).
Removalofanac
tiveLPUPAmodulerequireswillcausethetransmittertostopproducingRFsincePABRFinputwill
belost.
5.10.4 PAModuleBias
Re‐biasofthePAmodulesisnotrequiredontheMaxivaUAXseriestransmitters.
5.10.5 PAModulePhasing
PhasingofthePAmodules(andthepalle tinsidethem)istightlyc on tr o lle datthefactory .NophasingofthePAmodules
isrequiredinthefield.PAmodulescanbeuse dinanylocationwi thout re‐phasing.
Note
Phasing between PABs is required to minimize PAB combiner reject power and it is accomplished via the
cables that go to the PAB combiners. The cables to the PAB combiners must be identical in length for
proper combining and maximum output power.
5.10.6 PSModuleRemovalandReplacement
STEP 1 LoosenthumbscrewonfrontofPSmoduleandcarefullypullthemoduleout
oftherack.
STEP 2 Inspecttheconnectorsontherearofthereplacementmoduletobesure
thereisnodamagetothePSconnectors.
STEP 3 InspectthePSconnectorsinsidetheracktoconfirmthereisnoblockageor
damageonrackconnectors.
STEP 4 SlidethePAmodulegentlyintotherack(handledown)untilcontactismade
withthematingconnectors.
STEP 5 Pushevenlyonthemodulehandle(usetheoutsideedgesofthehandleto
avoiddeformingthehandleinthecenter)withaslightsidetosidemotionto
helpalignthematingconnectors.
STEP 6 FingertightenthePSmodulethumbscrew.Donottightenthumbscrewwith
ascrewdriver.
STEP 7 Endofprocedure.
5.10.7 VerificationofFailedFET
EachPAmodulecontainsonePApalletboard.EachpalletcontainstwoFETs.InordertoidentifyafailedFETusethe
followingprocedure:
STEP 1
RemovethePAmodulefromthesystem.Allowittocoolifitishottothe
touch.
STEP 2 RemovethePAmodulecover.
STEP 3 Useavoltmeter(Fluke87forexample)tomeasuretheresistancebetween
theFETgatesandground.