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

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
iv
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
I
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

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
I
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

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
I
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.

Rev.1.0
Getting Acquainted 1—7
=
Frequency Range 87.9-107.9MHz
RFPowerOutput
FMX30
FMX100
FMX250
(VSWR1.5:1orbetter)
3-30 watts,adjustable
10-100 watts,adjustable
20-250 watts,adjustable
RFOutputImpedance 50Ω
Frequency StabilityMeetsFCC specificationsfrom0-50
degreesC
AudioInputImpedance 50 kΩbridging,balanced,or600 Ω
AudioInputLevelSelectablefor-10 dBmto+10 dBmfor
75 kHzdeviation at400 Hz
Pre-emphasisSelectablefor25,50,or75 µsec;orFlat
AudioResponseConformsto75 µsecpre-emphasiscurve
asfollows
Completetransmitter±0.30 dB(50 Hz-10 kHz)
±1.0dB(10 kHz-15 kHz)
Exciteronly±0.25 dB(50 Hz-15 kHz
Distortion (THD +Noise)
CompletetransmitterLess than 0.7%(at15 kHz)
ExciteronlyLess than 0.3%(50 Hz-15 kHz)
Stereo Separation
CompletetransmitterBetterthan -40 dB(50 Hz-15 kHz)
ExciteronlyBetterthan -40 dB(50 Hz-15 kHz)
CrosstalkMainintosub,betterthan -40 dB
Sub intomain,betterthan -40 dB
Stereo Pilot19 kHz±2Hz,9%modulation
SubcarrierSuppression 50 dBbelow±75 kHzdeviation
FMS/NRatio(FMnoise)
CompletetransmitterBetterthan -60 dB
ExciteronlyBetterthan -70 dB

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
I
1—8
AMS/NRatioAsynchronousand synchronousnoise
betterthan FCC requirements
RFBandwidth±120 kHz,betterthan -35 dB
±240 kHz,betterthan -45 dB
RFSpuriousProductsBetterthan -70 dB
Operating EnvironmentTemperature(0oC-50oC)
Humidity(0-80%at20oC)
MaximumAltitude (3,000 meters;9843
feet)
ACPower
FMX30
FMX100
FMX250
DC Power
FMX30
FMX100
FMX250
100,120,220,or240 volts(+10%/15%);
50/60 Hz
115 VA
297 VA
550 VA
24-36 volts(36 voltsat3ampsrequired
forfull outputpower)
36-62 volts(48 voltsat5ampsrequired
forfull outputpower)
36-62 volts(72 voltsat8ampsrequired
forfull outputpower)
Note:Note:Wesetvoltage and ampererequirementstoassistyou in
designing yoursystem.Depending on youroperating frequency,
actualrequirementsformaximumvoltage and currentreadingsare
10-15%lowerthan stated.
RegulatoryType notified forFCC parts73 and 74
MeetsFCC,DOC,and CCIR
requirements
Dimensions13.5x41.9x44.5cm
(5.25 x16.5x17.5inches)
WeightFMX30
FMX100
FMX250
10.5kg(23 lbs)
13.6kg(30 lbs)shipping weight
11.4kg(25 lbs)
14.5kg(32 lbs)shipping weight
16.8kg(37 lbs)20.0kg(44 lbs)shipping
weight

Rev.1.0
Getting Acquainted 1—9
MonauralSensitivity
(demodulated,de-emphasized)3.5µVforsignal-to-noise>50 dB
12.6µVforsignal-to-noise>60 dB
Stereo Sensitivity
(19–kHzpilotfrequency added)2.8µVforsignal-to-noise>40 dB
8µVforsignal-to-noise>50 dB
31µVforsignal-to-noise>60 dB
ConnectorStandardtype N,50 Ω
Shipping Weight1lb

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
I
1—10
CrownBroadcastassumesthe responsibilityforproviding you asafeproductand
safetyguidelinesduring itsuse.“Safety”meansprotection toall individualswho
install,operate,and servicethe transmitteraswell asprotection ofthe transmitter
itself. Topromotesafety,weusestandardhazardalertlabeling on the productand
inthismanual.Followthe associated guidelinestoavoidpotentialhazard.
1.5.1Dangers
DANGERrepresentsthe mostseverehazardalert. Extremebodilyharmordeath
will occurifDANGERguidelinesarenotfollowed.
1.5.2Warnings
WARNINGrepresentshazardswhichcouldresultinsevereinjuryordeath.
1.5.3Cautions
CAUTIONindicatespotentialpersonalinjury,orequipmentorpropertydamage if
the associated guidelinesarenotfollowed.Particularcautionsinthistextalso
indicateunauthorized radio-frequency operation.
Illustration 1–4 HazardWarning
DANGER
Severshock hazard!
Turnpoweroff and wait
approximtely1minutefor
capcitorstodischarge
beforehandling them.
Severityof
hazard
Explanation of
hazard
Pictorialor
written
description
ofhazard

Installation 2—1
Thissection providesimportantguidelinesforinstalling your
transmitter.Reviewthisinformation carefullyforproper
installation.

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
2—2
You can install the FMtransmitterinastandardcomponentrack oron asuitable
surfacesuchasabenchordesk.Inanycase,the area shouldbe asclean and well-
ventilated aspossible.Always allowforatleast2cmofclearanceunderthe unitfor
ventilation.If you setthe transmitteron aflatsurface,install spacerson the bottom
coverplate.If you install the transmitterinarack,provide adequateclearanceabove
and below.Donotlocatethe transmitterdirectlyaboveahotpieceofequipment.
The FMX30,FMX100,and FMX250 operateon 100,120,220,or240 voltsAC(50 or
60 Hz;singlephase).Eachtransmittercan operateon DC poweraswell (28 volts
forthe FMX30,36 voltsforthe FMX100,and 62 voltsforthe FMX250).The
transmittercan operateon lowerDC voltage,butwithreduced RFoutputpower
(see section 1.2).Inaddition,the transmitterisolatesthe ACand DC sources;both
can be connected atthe sametimetoprovide batterybackup inthe eventofan AC
powerfailure.
2.2.1ACLine Voltage Setting
Tochange the voltage setting,followthesesteps:
1.Disconnectthe powercordifitisattached.
2.Open the coverofthe powerconnectorassemblyusing asmall,flatblade
screwdriver.See Illustration 2–1,Removing the PowerConnectorCover.
3. Insertthe screwdriverintothe voltage selection slotand removethe drum
fromthe assembly.
4.Rotatethe drumtoselectthe desired voltage.See Section 2.2,PowerConnec-
tions.
5.Replacethe drumand coverand check tosee thatthe correctvoltage appears
inthe connectorwindow.
6.Connectthe ACpowercord.
CAUTION
Possibleequipmentdamage!
Beforeoperating the transmitterforthe first
time,check forthe properACline voltage set-
ting and frequency described inSection 2.2,
PowerConnectionsand Section 2.3,Frequency
(Channel)Selection.

Rev.1.0
Installation 2—3
Illustration 2–1 Removing the PowerConnectorCover
Illustration 2–2 Selecting an ACLine Voltage
120Vac
120Vac
220Vac
240Vac

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
2—4
2.2.2Fuses
The fuseholdersarelocated inthe powerconnectorassemblyjustbelowthe voltage
selector.:
For100 to120 VACoperation,usethe fuseinstalled atthe factory.For220 to240
VACoperation,usethe slow-blowfuselocated inahardwarekitwithinthe
transmitterpackaging.Consultthe following table:
Illustration 2–3 FuseHolder
TransmitterInputPowerFuse
FMX30 100-120 V3A
220-240 V1.5A
FMX100 100-120 V6.3
220-240 V4A
FMX250 100-120 V12.5A
220-240 V6.3A
Table2-1FuseChart

Rev.1.0
Installation 2—5
The transmitting frequency forCrownFMXseriestransmittersissetfromafront
panelcontrol.However,you mustsetthe modulation compensatorforthe operating
frequency.
2.3.1Modulation Compensator
The Modulation trim-potentiometer,(see Section 2–4,Modulation Compensator
Settings),compensatesforslightvariationsindeviation sensitivitywithfrequency.
Setthe trim-potdialaccording tothe following graph:
Thesecompensatorsettingsareapproximate.Eachmarkon the potentiometer
representsabout1.8%modulation compensation.Formoreexactsettings,see
Section 5.2.2,CompositeOutput.
Replacethe top coverbeforeoperating the transmitter.
2.3.2RFTuning Adjustments
All the RFstagesarebroadband tocoverthe 88 to108 MHzbroadcastband.The RF
amplifierstagesrequireno tuning.
Note: If you requested it, the FSK chipon the RFExciterBoardhasbeen
pre-programmed foryouroperating frequency.Thischipis
replaceable.Shouldyou need tochange the location ofyour
translator,contactCrownBroadcastforareplacementchipwithyour
newFSK ID.TodisableautoID,removethe jumperfromthe autoID
location on headerHD2on the RFExciterBoard.
Illustration 2–4 Modulation CompensatorSettings
Modulation Compensation Pot Setting
0
10
20
30
40
50
60
70
80
90
75 80 85 90 95 100 105 110
Frequency (MHz)

Rev.1.0
FMX30/FMX100/FMX250 User’sManual
2—6
If you haveatransmitterequipped withthe receiveroption,you will need tosetthe
receiving orincoming frequency.
1.Withthe top coverremoved,locatethe receivermoduleand the twoswitches
(labeled SW1and SW2).
2.UseTable2-2,ReceiverFrequency Selection,tosetthe switchesforthe desired
incoming frequency.
Aftersetting the frequency,returntoSection 2.3.1,Modulation Compensator,toset
the modulation compensator.
Note: If you requested it, the FSK chipon the RFExciterBoardhasbeen
pre-programmed foryouroperating frequency.Thischipis
replaceable.Shouldyou need tochange the location ofyour
translator,contactCrownBroadcastforareplacementchipwithyour
newFSK ID.
Replacethe top coverbeforeoperating the transmitter.
Illustration 2–5 ReceiverModuleSwitches
Receiver
ModuleFrequency Selection Switches