Specifications

Section-5 Maintenance
October 17, 2013
5‐6
Copyright©2013,HarrisBroadcast
WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
SeeSection2.13onpage2‐21andfollowingsectionsforLPUandTCUwebbrowserconnectionandlogin
information.Harrisr
ecommendsuseoftheChromeorFirefoxwebbrowser.
Calibrateusi
ngthelocalTCUGUIorwebbrowserbynavigatingtotheLPUUAXHome>Config>System
Configuration>Cal’SystemCalibration’screenandpressthepulldownmenuarrowtoshowthecalibrationoptions
(seeFigure5‐3onle
ftbelow).
Forwardc
alibrationmustbeperformedfirstandisfollowedbyreflectedcalibration.Afterselectingthecalibration
type,presstheStartCalsoftkeytobeginthecalibrationprocess(seeFigure5‐3onrigh
tbelow).
Figure 5-3 on
left - System Calibration options on right - System Calibration started
Powerc
alibrationsinclude:
• Forward‐Powerattheoutputofthetransmitteramplifyingstages,beforethebandpassfilter(BPF).
• Reflected‐Poweratthe outputofthetransmitteramplifyingstagesandbeforethebandpassfilter(BPF).
• UDCOut‐PoweratoutputofLPUmodulatorstage(SMAconnectoronupperrearofLPU)
• LPUForward‐Powerattheoutput(typeN)oftheLPUamplifiersection
• PAB#Forward‐Powerattheoutputofindividualpoweramplifierblocks
• PAB#Reflected‐Powerattheoutputofindividualpoweramplifierblocks
Note
Re-calibration is not typically required in the field once the transmitter is in service. Re-calibration would
be indicated only for verification, frequency change, or after major service work involving replacement of
one or more power metering components has been performed.
EquipmentUsed:
• AnHPEPM‐seriesPowerMeterand8482HPowerSensor,orAgilentE4418BandType“N”toSMAadapter(or
equivalent).MetershouldbecapableofdisplayingmeasuredvaluesinWattsorindBm.
• Precisiondi rectional couplers(precisioninthesensethatthecouplingratioshavebeenmeasuredforthe
operatingfrequenciestoahighdegreeofprecision).
Caution
THE REFLECTED POWER FAULTS ARE DISABLED DURING THE POWER
CALIBRATION PROCEDURE. EXIT FROM THE CALIBRATION PROCEDURE
WHEN CALIBRATION IS COMPLETE TO AUTOMATICALLY REACTIVATE
REFLECTED POWER PROTECTIONS.
Note
Read and understand the applicable power calibration procedure before beginning. The procedures below
assume use of the LCD display and the buttons on the front of the LPU. The procedure can also be per
-
formed using the web browser screens. Screen captures, such as seen in Figure 5-3 on page 5-6, should be
assumed to be via web browser.