Specifications

Section-5 Maintenance
October 17, 2013
5‐8
Copyright©2013,HarrisBroadcast
WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
Note
RTAC precorrection is automatically disabled and power control is automatically switched to manual
mode during calibration.
5.4.2 ForwardCalibrationProcedure
STEP 1 ZeroandcalibrateRMSpowermeterfollowingthemanufacturer’s
proceduresforspecificmodel.
STEP 2 Locatesystemforwardcalibrationsampleport,whichshouldhavebeen
measuredandlabeledatthefactorywiththecouplingfactorforyour
frequencyofoperation.Thiswilleitherbeaforwardportonthepre‐filter
directionalcoupler,leftavailableforthispurposeinastand‐alone(i.e.non‐
racked)configuration,orth
efrontpanelPRE‐FILTERFWD (forward)power
sampleinarackedconfiguration.Ifthecouplingfactorisinquestion,orif
thefrequencyhaschanged,theapplicableforwardcouple rportshouldbe
sweptwithanetworkanalyzertodeterminethecorrectcouplingfactorat
thefrequencyofinterest.Remembertoincludeth
elossintheroutingcables
inthenetworkanalyzermeasurementwhencharacterizingthebulkhead
measurementpoint.
STEP 3 Oncethecouplingvalueisdetermined,enterthisvalueasanoffsetinthe
powermeter,setthemeter’sdisplaytoreadindBm(3digitsissufficient,i.e.
xx.xdBm),andconnectthemeter’ssensortothisport.
Note
Please ensure that the sample level present at this point (max system output, in dBm, minus the coupling
factor) does not exceed the maximum input range of power sensor being used.
STEP 4 IfdualLPUsareinusesettheTCUDriverControltoManual.SelecttheLPU
tobecalibratedastheactiveLPU.
STEP 5 PressandholdtheLowerbuttonfor30secondstoreducetransmitterRF
outputatturn‐on.UsetheTCULowerbuttonfordualsystems.UsetheLPU
LowerbuttonifasingleLPUispresent.
STEP 6 PressTCUOnbuttonifpresent.PressselectedLPUOnbuttonifnoTCUis
presetn.
STEP 7 EntertheForwardcalibrationmenu,eitherfromthefrontpanel(Setup>
XMTRPOWERSETTINGS>POWERCAL>FORWARD)orfromtheWebGUI.
See’SystemCalibration’(leftside)inFigure5‐3onpage5‐6.