Specifications

Maxiva ULX Series
November 11, 2013
4‐21
888‐2628‐300 WARNING:Disconnectprimarypowerpriortoservicing.
Copyright©2013,HarrisBroadcast
TheCD2007outputamplifierboardandthephaseandgainboardreceivetheirpowerfromthepowersupplyboard
mountedonthetray.Thispowersupplyproduces28Vdcat4.5ampsmaximum.
Thephaseandgainboardprovidesacontinuouslyvariablephasechan geof180degrees,whichisusedtocombine
multiplePAcabinets.Italsohasanattenuator,drivenbythetransmitter’sALC(automaticlevelcontrol)circuit,
whichhasa0to15dBvariablerange.Thephaseandgainboardis
usedbythetransmittertocontrolcabinetpower
(bydrivingthePAmoduleswithmoreorlessinputpower)andcabinetphasing.
Figure4‐12givesablockdiagramof
thephaseandgainboard.
Figure 4-12 Phase and Gain Board Block Diagram
TheCD2007outputamplifierhasapeakratingof35wattsandisgenerallyoperatedovera0.3to4.0wattaverage
rangefordigital,toallowadequatepeaktoaveragepowerheadroom.IntheanalogTVmodeitsoutputisupto6
wattspeakofsyncwith10%aural.
At28Vdcsupplyvoltagethisamplifierrequiresapproximately5.2ampsto
produce35wattsoutput.Ithasanefficiencyof24%at35wattsoutput.
Thetypicalgainofthepredrivertrayis32dB,andthegainofthepredriverassembly(whichincludesthe2‐way
splitter)is28dB.
4.6.3 IPA(driver)andPAModule
ThepurposeofMaxivaULXPAandIPA(driver)moduleistoamplifymodulatedRFsignalprovidingapproximately19
dBgainoverTVfrequencybandsIV/V.Themoduleincludesitsownpowersupplysectionthatgeneratesdrainbias
forRFpowergeneratingsectionofthemodule.ThePAmoduleisdesigned
tobeusedwithinterrestrialtelevision
standardsG,H,I,K,KI,L,M,NwithcolorsystemsPAL,SECAMorNTSC.ThePAmodulecanoperateincommon
amplificationmodewithsingleordualauralsub‐carrierpresentalongwiththevisualamplitudemodulatedcarrier.
ThePAandIPA
(driver)modulescanbealsousedtoamplifydigitallymodulatedRFsignals,suchasCOFDMand8‐
VSB.Themodulationbandwidthisnottoexceed8MHz.