Specifications

Section-5 Maintenance
October 17, 2013
5‐30
Copyright©2013,HarrisBroadcast
WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
Figure 5-18 FWD cable direct to REF port
STEP 15
Thesystemwillnowpromptyoutoreconnectthecablesintheiroriginal
configuration(FWDtoFWD,RFLDtoREV)bef oreproceeding.Ifyouforgetto
performthisstep,thesystemwillmostlikelyimmediatelygointoVSWR
foldbackwhenyouattempttoreturntonormaloperation.
STEP 16 Proce dur ecomplete.
5.6.3.2 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forwardoutputpowerlevelas
indicatedonyourmeter,buttheADCisindicatingnear‐zerovalues,oriftheAD
Cvalueatthehighpointequals(oris
lessthan)thevalueatthelowpoint,thesystemwilldiscardthecalibration.Inthiscase,afterraisingthesystem
outputtothelevelindicated,checktheactualpowerpresentattheFWDsamplecable(rememberturnoffthe
powermeter ’soff
set.)Youshouldhaveapproximately0dBmatthispoint(thecableendthatconnectstotheLPU
input)atfullsystemforwardpower.Ifyoudonot,pleaseverifythecabling,workingstepbystepfromtheLPUend
backtowardsthecoupler.
Ifan
yPAsarefaultedduringthecalibration,thesystemwillconsideritinvalidanddiscardit.ReplaceanyfaultyPAs,
andperformthecalibrationagain.
5.6.4 CalibrateUDCOut
UDCreferstotheoutputoftheupdownconverterboard(modulatorsectionoftheLPU)ontherearoftheLPU.This
isafemaleSMAconnector.
STEP 1
ZeroandcalibrateRMSpowermeter,followingtheapplicable
manufacturer’sproceduresforspecificmodel.
Note
The power meter reads average power. Conversion to peak visual power is required. See Section 5.6.1 on
page 5-21 for methodology.
STEP 2
LocatetheUDCSMAconnectorontherearoftheLPUtobecalibrated(lower
left),removetheRFcable,andconnectthepowermeterprobe.
STEP 3 Connectthevideosourcetothevideoinputofthetransmitter.Setvideo
sourcetoblackpicturewithzerosetup.