Crown FMX30 User manual

©2003 CrownBroadcast, adivision ofInternationalRadioand Electronics,Inc.
25166 LeerDrive,Elkhart, Indiana,46514-5425 U.S.A.
[phone]

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
ii
Revision PrintDate
Rev.1.0January2003
©2002,InternationalRadioand Electronics,Inc.
Portionsofthisdocumentwereoriginallycopyrighted byMichaelP.Axman in1991.
All rightsreserved.Nopartofthispublication maybe reproduced,transmitted,
transcribed,stored inaretrievalsystem,ortranslated intoanylanguage inanyform
byanymeanswithoutthe written permission ofInternationalRadioand
Electronics,Inc.
Printed inU.S.A.
Sonyand RCAaretrademarks oftheirrespectivecompanies.
IRECattemptstoprovide information thatisaccurate,complete,and useful.Should
you find inadequaciesinthe text, pleasesend yourcommentstothe following
address:

Rev.1.0
iii
TableofContents
TableofContentsiii
Section 1—Getting Acquainted
1.1YourTransmitter.........................................................................................1-2
1.2Applicationsand Options.............................................................................1-3
1.2.1Stand-Alone.............................................................................................1-4
1.2.2Backup ....................................................................................................1-4
1.2.3Booster....................................................................................................1-4
1.2.4Exciter.....................................................................................................1-4
1.2.5Translator................................................................................................1-5
1.2.6Satellator.................................................................................................1-6
1.2.7Nearcasting.............................................................................................1-6
1.3Transmitter/ExciterSpecifications...............................................................1-7
1.4ReceiverSpecifications................................................................................1-9
1.5SafetyConsiderations................................................................................1-10
1.5.1Dangers.................................................................................................1-10
1.5.2Warnings...............................................................................................1-10
1.5.3Cautions................................................................................................1-10
Section 2—Installation
2.1Operating Location......................................................................................2-2
2.2PowerConnections......................................................................................2-2
2.2.1ACLine Voltage Setting...........................................................................2-2
2.2.2Fuses.......................................................................................................2-4
2.3Frequency (Channel)Selection....................................................................2-5
2.3.1Modulation Compensator........................................................................2-5
2.3.2RFTuning Adjustments...........................................................................2-5
2.4ReceiverFrequency Selection......................................................................2-6
2.5RFConnections...........................................................................................2-8
2.6AudioInputConnections.............................................................................2-9
2.7SCAInputConnections..............................................................................2-11
2.8CompositeInputConnection .....................................................................2-11
2.9AudioMonitorConnections.......................................................................2-12
2.10 Pre-emphasisSelection.............................................................................2-12
2.11 ProcessorBypass Option ..........................................................................2-12
2.12 ProgramInputFaultTime-out ...................................................................2-13
2.13 RemoteI/OConnector...............................................................................2-14
Section 3—Operation
3.1InitialPower-up Procedures........................................................................3-2
3.2Controlsand Display....................................................................................3-2
3.2.1FrontPanel..............................................................................................3-2
3.2.2DC Breaker..............................................................................................3-4
3.3Operating the FMX.......................................................................................3-4

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3.3.1Passwords...............................................................................................3-4
3.3.2MainFunction List...................................................................................3-4
3.3.3ReadingsFunction List............................................................................3-5
3.3.4SettingsFunction List..............................................................................3-6
3.3.5FactorySetting Functions........................................................................3-7
3.3.6AudioMonitor.........................................................................................3-7
3.3.7FaultLog .................................................................................................3-7
3.4Power-up procedure....................................................................................3-8
3.4.1ApplyPower............................................................................................3-8
3.4.2EnterInitialSettings................................................................................3-8
3.4.3Transmit..................................................................................................3-8
Section 4—PrinciplesofOperation
4.1Block Diagram.............................................................................................4-2
4.2AudioProcessorCircuitBoard.....................................................................4-3
4.2.1Balanced Input ........................................................................................4-3
4.2.2AudioProcessor......................................................................................4-3
4.3Stereo GeneratorCircuitBoard....................................................................4-4
4.3.1 Low-pass filter........................................................................................4-4
4.3.2Stereo Generator.....................................................................................4-5
4.3.3SCAInput................................................................................................4-5
4.3.4Processed Audio.....................................................................................4-5
4.4RFExciterCircuitBoard...............................................................................4-6
4.5DigitalManagementSystem........................................................................4-7
4.5.1Metering Boards......................................................................................4-7
4.5.2FrontPanel..............................................................................................4-7
4.6Motherboard................................................................................................4-8
4.7Voltage RegulatorCircuitBoard...................................................................4-8
4.8PowerRegulatorCircuitBoard....................................................................4-9
4.9RFDriver/Amplifier(FM30)..........................................................................4-9
4.10 RFDriver(FM100/FM250)...........................................................................4-9
4.11 RFAmplifier(FM100/FM250)......................................................................4-9
4.12 Chassis......................................................................................................4-10
4.13 RFOutputFilter&Reflectometer...............................................................4-11
4.14 ReceiverCircuitBoardOption....................................................................4-11
Section 5—Serviceand Support
5.1Service.........................................................................................................4-2
5.2 24–HourSupport.........................................................................................4-2
5.3SpareParts..................................................................................................4-2

Rev.1.0
Getting Acquainted 1—1
I
INFORMATION
Thissection providesageneraldescription ofthe FMX30,
FMX100,and FMX250 transmittersand introducesyou tosafety
conventionsused withinthisdocument.Reviewthismaterial
beforeinstalling oroperating the transmitter.

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
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1—2
The FMX30,FMX100,and FMX250 aremembersofafamilyofFMstereo broadcast
transmitters.Crowntransmittersareknownfortheirintegration,ease-of-use,and
reliability.
The integration ismostapparentinthe standardtransmitterconfiguration which
incorporatesaudioprocessing,stereo generation,and RFamplification without
compromised signalquality.AsingleCrowntransmittercan replaceseveralpieces
ofequipmentinatraditionalsystem.
Ease-of-useisapparentinthe user-friendlyfrontpanelinterfaceand inthe
installation procedure.Simplyselectyouroperating frequency add an audiosource,
attachan antenna,and connectACorDC powerand you'rereadytobroadcast. Of
course,the FMseriesoftransmittersalsofeaturemoresophisticated inputsand
monitoring connectionsifneeded.
ReliabilityisaCrowntradition.The firstCrowntransmittersweredesigned for
rigorsofworldwide and potentiallyportableuse.The modulardesign,quality
components,engineering approach,and high production standardsensurestable
performance.Formoredirectmonitoring,the frontpanelincludesasinglecontrol
knob,afourline displayand bargraph indicators.Automaticcontrolcircuitry
providesprotection forhigh VSWRaswell ashigh current, voltage,and
temperatureconditions.
Thismanualdescribesthe FMX30,FMX100,and FMX250
Becauseall three transmitterssharecommon design factors.Specificproduct
differencesarenoted throughoutthe manual.Inphysicalappearance,the
FMX30 differsfromthe FMX100 and FMX250 inthatitlacks the poweramplifier
and cooling fan assemblyon the back panel.
Illustration 1–1 FMX250 FMBroadcastTransmitter

Rev.1.0
Getting Acquainted 1—3
Crowntransmittersaredesigned forversatilityinapplications.Theyhavebeen used
asstand-alone and backup transmittersand inbooster,translator,satellator,and
nearcastapplications.The following discussion describestheseapplicationsfurther.
Modelnumbersdescribe the configuration ofthe product(whichhastodo withits
intended purpose)and the RFoutputpowerwhichyou can expect.
The numberportion ofeachnamerepresentsthe maximumRFoutputpower.The
FMX250,forexample,can generateup to250 wattsofRFoutputpower.
Suffixlettersdescribe the configuration.The FMX250T,forexample,isthe standard
ortransmitterconfiguration.Exceptwherespecified,thisdocumentdescribesthe
transmitterconfiguration.Inthisconfiguration,the productincludesthe following
components(functions):
•audioprocessor
•stereo generator
•RFexciter
•metering
•low-pass filter
Illustration 1–2 Standard(Transmitter) Configuration
Stereo
Generator
Audio
Processor
Low-Pass
Filtering
Metering
RFExciter

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1—4
1.2.1Stand-Alone
Inthe standardconfiguration,the FMX30,FMX100,and FMX250 areidealstand-
alone transmitters.When you add an audiosource(monaural,L/Rstereo,or
compositesignal),an antenna,and ACorDC power,the transmitterbecomesa
completeFMstereo broadcaststation,capableofserving acommunity.
Asstand-alone transmitters,Crownunitsoften replacemultiplepiecesof
equipmentinatraditionalsetup (exciter,audioprocessor,RFamplifier).
1.2.2Backup
Inthe standardconfiguration,Crowntransmittersarealsoused inbackup
applications.Shouldyourprimarytransmitterbecomedisabled,you can continue
tobroadcastwhilerepairstakeplace.Inaddition,the FMtransmitterscan replace
disabled portionsofyourexisting systemincluding the exciter,audioprocessor,or
amplifier.Transferswitcheson eachside ofthe existing and backup transmitters
makethe change-overpossiblewithminimaldowntime.
The DC operation option ofthe FMX30,FMX100,and FMX250 makethemattractive
backup unitsforthosetimeswhen ACpowerislost.
1.2.3Booster
Alsointhe standardconfiguration,Crowntransmittershavebeen used asbooster
transmitters.Boosterapplicationstypicallyinvolvecertaingeographicfactorswhich
preventyoursystemfrombroadcasting tothe full coverage area allowable.For
example,amountainrange mightblock yoursignaltoaportion ofyourcoverage
area.CarefulplacementofaCrowntransmitter,operating on the samefrequency as
yourprimarytransmitter,can helpyou reachfull coverage.Anexternalreceiverand
specialantenna arerequired touseCrownFMtransmittersasboosters.
1.2.4Exciter
Inaddition tothe standardconfiguration,CrownFMtransmittersareavailablein
optionalconfigurationstomeetavarietyofneeds.
An“E”suffix,asinthe FMX30E,forexample,representsan exciter-only
configuration.Inthisconfiguration,the audioprocessorand stereo generator
boardsarereplaced withcircuitrytobypass theirfunction.The exciter
configurationsarethe leastexpensivewaytogetCrown-qualitycomponentsinto
yourtransmission system.
You mightconsiderthe Crownexciterwhen otherportionsofyoursystemare
performing satisfactorilyand you wanttomaximizeyourinvestmentinpresent
equipment.

Rev.1.0
Getting Acquainted 1—5
1.2.5Translator
The FMX30Rreceiveroption replacesthe audioprocessorand stereo generator
boardswithareceivermodule.Thisadded featuremakesCrowntransmittersideal
fortranslatorserviceinterrestrial-fed networks.Thesenetworks representa
popularand effectivewaytoincreaseyourbroadcasting coverage.Translators,
acting asrepeateremitters,arenecessarylinks inthischainofevents.
Traditionally,networkengineershaverelied on multiplestepsand multiplepiecesof
equipmenttoaccomplishthe task.Othershaveintegrated the translatorfunction
(receiverand exciter) tofeed an amplifier.Crown,on the otherhand,startswithan
integrated transmitterand addsasolid-stateReceiverModuletoformthe ideal
translator.
Thisoption enablesRFinand RFouton anyofCrown’sFMseriesoftransmitters.
Inaddition,the modulesuppliesacompositeoutputtothe RFexciterportion ofthe
transmitter.Fromhere,the signalisbroughttofull powerbythe built-inpower
amplifierforretransmission.The ReceiverModulehasbeen specificallydesigned to
handleSCAchanneloutputup to100 kHzforaudioand high-speed data.
FSK IDprogramming isbuilt-intoensurecompliancewithFCC regulations
regarding the on-airidentification oftranslators.Simplyspecifythe call sign ofthe
repeaterstation when ordering.Shouldyou need tochange the location ofthe
translator,replacementFSK chipsareavailable.The ReceiverModuleoption should
be ordered atthe timeofinitialtransmitterpurchase.However,an option kitis
availableforfieldconverting existing Crownunits.
Inthe translatorconfiguration therearedifferencesinthe function ofthe front
panel,See Section 3.7,DigitalMultimeterforadescription.
Illustration 1–3 Crown’sIntegrated Translator
RFExciter
Receiver
Module
(Option)
RFIn Low-Pass
FilterRFOut
Metering

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1—6
1.2.6Satellator
Crowntransmittersinclude automaticcall sign oroperating frequency
transmission inaMorsecode style.Thisfeatureisintended foruseinsatellite-fed
networks.Transmittersequipped inthisfashion areoften knownas“satellators.”
Connectthe transmittertoyoursatellitereceiverand the built-inFSK IDerdoesthe
rest—shifting the frequency tocomplywithFCC requirementsand inamanner
thatisunnoticeabletothe listener.
1.2.7Nearcasting
SomeCrownunitsfunction as“nearcast”transmitters.Theirlow-poweroutputis
notdesigned forbroadcasting asignalbutfortransmitting ittolocalreceivers,
sometimeswithinthe sameroom.Crowntransmittershavebeen used inthisway
forlanguage translation,forrebroadcasting the audioofsporting eventswithina
stadium,and forspecialized localradio.Crownmakesadedicated nearcast
transmitter.However,the FMX30 isalsoappropriateforthisapplication.