Blonder tongue FOCN Series User manual

INSTRUCTION MANUAL
OneJakeBrownRoad
OldBridge,NJ08857-1000USA
(800)523-6049•(732)679-4000•FAX:(732)679-4353
www.blondertongue.com
©2010BlonderTongueLaboratories,Inc.Allrightsreserved.Specificationsaresubjecttochangewithoutnotice.Trademarksarethepropertyoftheirrespectiveowner.
FOCN Series
FiberOpticCompactNode
 Model StockNo.
FOCN-S4S-201 7420A-1
FOCN-S4S-204 7420A-4
FOCN-S4S-205 7420A-5
Status Date DocumentNo. IssueNo. Author
Active September28,2010 651215000C 3 KK
Obsolete May15,2009 651215000B 2 KK

2 FOCN
InstructionManual
Safety Precautions
Theopticalemissionsfromtheunitsarelaser-basedClassIIIb,andmaypresenteyehazardsifimproperlyused.NEVER USE
ANY KIND OF OPTICAL INSTRUMENT TO VIEW THE OPTICAL OUTPUT OF THE UNIT.
Asalways,becarefulwhenworkingwithopticalfibers.Fiberscancausepainfulinjuryiftheypenetratetheskin.
Laser Safety Procedures
ALWAYS readtheproductdatasheetandthelasersafetylabelbeforepoweringtheproduct.Notetheoperatingwavelength,
opticaloutputpower,andsafetyclassifications.
Ifsafetygogglesorothereyeprotectionareused,becertainthattheprotectioniseffectiveatthewavelength(s)emittedby
thedeviceundertestBEFORE applyingpower.
ALWAYSconnectafibertotheoutputofthedeviceBEFOREpowerisapplied.Powershouldneverbeappliedwithoutan
attachedfiberoutput.Ifthedevicehasaconnectoroutput,aconnectorshouldbeattachedthatis
connectedtoafiber.Thisensuresthatalllightisconfinedwithinthefiberwaveguide,virtuallyeliminatingallpotential
hazard.
NEVER look in the end of a fiber to see if light is coming out. NEVER! Mostfiberopticlaserwavelengths(1310 nmand1550
nm)aretotallyinvisibletotheunaidedeyeandwillcausepermanentdamage.Shorterwavelengthlasers(e.g.780nm)are
visibleandareverydamaging.Alwaysuseinstruments,suchasanopticalpowermeter,toverifylightoutput.
NEVER, NEVER, NEVERlookintotheendofafiberonapowerdevicewithANYsortofmagnifyingdevice.
Thisincludesmicroscopes,eyeloupes,andmagnifyingglasses.ThisWILLcausepermanent,irreversibleburnonyourretina.
Alwaysdoublecheckthatpowerisdisconnectedbeforeusingsuchdevices.Ifpossible,completelydisconnecttheunitfrom
anypowersource.
Ifyouhavequestionsaboutlasersafetyprocedures,pleasecallBlonderTonguebeforepoweringyourproduct.
LasersafetyclassesfortheFOCN:
Storing the Unit
Ifaunitistobeoutofuseforanextendedperiodoftime,thefollowingstepsshouldbetakentoensurethe
preservationoftheunit:
 1. Thestoragetemperaturerangeis-20°Cto+70°C.
 2. Alowhumidityenvironmentispreferableforlongtermstorage.
 3. Allconnectorsshouldbecoveredwithactivedevicereceptaclecaps.
INVISIBLE LASER RADIATION
EMITTED FROM END OF
FIBER OR CONNECTOR
AVOID EXPOSURE TO BEAM
Do not view beam directly with
optical instruments
INVISIBLE LASER RADIATION EMITTED FROM END OF FIBER OR CONNECTOR
AVOID EXPOSURE TO BEAM
Class IIIB Laser Product IEC-60625 1193 Max. Output 30 mW Wavelength: 1.3µm
Wavelength: 1.3µm
Max. Output: 30 mW
Class III Laser Product
AVOID EXPOSURE
INVISIBLE LASER
RADIATION EMMISSIONS
Warning: The optical emissions from the units are
laser-based and present eye
hazards. Follow all safety precautions
 Class WavelengthRange OpticalPowerAccessionLimits
 IIIb 180nmto400nm Varieswithandexposuretime.
  400nmto106nm 0.5Watt
TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER FROM THIS UNIT.
NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

3
FOCN
InstructionManual
Description
TheBlonderTongueFOCNisahighquality,costeffective,bidirectionalCATVnodefeaturingthelatestopticalreceiver
technology.Itisdesignedtooperatewithopticalinputlevelsrangingfrom-8dBmto+2dBm.TheFOCNhasaforward
bandwidthof54-1000MHzand5-42MHzReturnwithOptionalReturnLaserTransmitters.
FOCN Model Table
Model Stock No. Description
FOCN-S4S-201 7420-1 RxOnly(NoReturn)
FOCN-S4S-204 7420-4 Rxwith1310nm,4.8dBmDFBLaser
FOCN-S4S-205 7420-5 Rxwith1550nm,4.0dBmDFBLaser
TheFOCNcomeswithanACadapterwhichoperatesonaninputof100-240VAC50/60Hzandanoutputof12VDCat
1.25Amps.
Installation/Environmental Considerations
TheFOCNisspecifiedtooperatefrom-10°Cto+55°C.Itshouldbemountedinanadequatelyventilatedarea.Fora
longerlifespan,itshouldnotbeoperatedattheupperlimitofthetemperaturerange.Installationinwetareasorareas
ofextremelyhighhumidityshouldbeavoided.TheFOCNshouldnotbeinstalledinareasthatareaccessibletochildren.
TheFOCNmaybeinstalledandoperatedinanypositiononaflatsurface.Theunithastwoslotsinthebottomplateto
accommodatemountinghardware.Theunitshouldbemountedbyslidingoveronescrewandthentighteningtheother
screw.Ifmountingrequiresawoodscrew,use#6or#8(maximum)pan-headsheetmetalscrews.Thesearecommonly
availableathardwarestores.Ifmountingwithamachinescrew(totappedholes),use6-32pan-headscrews.
Optical Connectors
TheopticalconnectorsareavailableinSC/APCtypeterminations.
Powering
Applyonly+12VDCtoeitherthe“F”connectorclosesttothetopcoveroftheunit,orthroughapowerinserterinseries
withtheMainRFoutputconnector,the“F”connectorclosesttotheoutsideedgeofthehousing.
NOTE:thecenterconductorofthe“F”connectoris“+”andtheshieldisground.

4 FOCN
InstructionManual
Forward Optical Receivers
RF Output
FrequencyRange(+/-1.0dB):54-1000MHz(NTSC)
OutputLevel(@-1dBmopticalinput):*
 +28dBmV(@550MHz)
ReturnLoss:14dBmin.,16dBtypical
Impedance:75Ohm
CNR(@0dBmopticalinput):*>53dB
CSO(@-1dBmopticalinput):*>63dBc
CTB(@-1dBmopticalinput):*>65dBc
Slope:0dB
RFTestPoint(forward)-20dB;TypeF
Optical
Wavelength:1280-1610nm
OpticalInputPowerRange:+2dBmto-8dBm
ReturnLoss:>50dBwithAPCconnector
OpticalInputPowerTestPoint:
 1V/mW+/-0.1V
OpticalConnector:SC/APC,8°APC
 *NOTE:Typicallevels@0dBslopeto1000MHzwith8dBm
opticaltransmitterwithOMI@3.2%,&77NTSCchannel
loadingto550MHz&digitalloadingto1000MHz(-6dB
belowanalog).
Electrical & Mechanical
Dimensions:3”Hx6”Dx2.1”H
Weight:12oz.
OperatingTemperatureRange:
 -10to+55˚C(temperatureatthemountingplate)
EnclosureIPRating:IP20
Powering:+12VDC
 (viaexternalPowerSupply(included))
DCRipple:<50mV
PowerDissipation(withreturnTX):<7W
Return Optical Transmitters
Specifications
F-P & DFB Versions RF Input
FrequencyRange:(+/-1.0dB)5-42MHz(NTSC)
RFTestPoint(return):-20dB(external);TypeF
ReturnLoss(withReturnTXInstalled):
 >16dBwithintheReturnBand
ReturnPathNPR:15dBmin.ofNPRRange
 FP:37dBNPRThreshold
 DFB:41dBNPRThreshold
Optical
OpticalOutput:
 DFB=4.8dBm(3mW)@1310nm
 DFB=4.0dBm(2.5mW)@1550nm
ReturnLoss:>50dBwithAPCconnector
OpticalConnectorSC/APC,8°APC

5
FOCN
InstructionManual
Operational Setup – Receiver (Forward Path)
TheFOCNopticalreceiverasthelastcomponentinaspecificopticallinkwillprovidecarrier-to-noiseperformanceand
anRFoutputlevelthatisdependentonseveralparameters.TheRFinputleveltothesourceopticaltransmitterandthe
opticalinputleveltotheFOCNbasicallydeterminethelinkperformance.
Boththelasermodulationandthereceiveroutputlevelarebasicallylimitedbytotalpower.TheRFinputleveltoany
opticaltransmitterisdependentonthenumberofchannelsbeingtransmitted.Asthenumberofcarriedchannelsis
lowered,theRFinputleveltothetransmittercanberaised.ThisresultsinincreasedRFlevelsattheFOCNreceiver.This
improvesthecarrier-to-noiseratiooverthelink.Linksshouldbedesignedandtransmittersshouldbesetupusingvalues
thatrepresentthemaximumnumberofchannelslikelytobecarried.
Thefollowingchartassumesapproximately77channelsfrom55MHzto550MHzanddigitalloadingfrom550MHzto
1000MHzat–6dBbelowanalog.TheRFlevelsaremeasuredat547.25MHz.
Althoughthenodewilloperateatopticalinputlevelsashighas+2dBm,thereislittleimprovementintheC/
Nperformanceofthenodeatopticalinputlevelsabove0dBm.Foroptimumdistortionperformanceitisrecommended
thattheopticalinputtothenodebekeptatorbelow0dBm.TheFOCN'sRFoutputisdirectlyproportionatetothe
opticalinputlevel.Ifloweroutputisdesired,theunitshouldbeloweredbyaddinganin-linepadtotheRFoutput
toreducetheoutputlevel.ThiswillmaintainoptimumC/Nperformance.ThiswillalsoreducetheOMIofthereturn
transmitterifsoequipped.
ThefollowingchartshowstheapproximateC/Nperformanceatvariousinputlevelsandchannelloading.
Thisperformancecanvaryconsiderablydependinguponfiberandlaserperformancesoitispresentedas
adesignaidonly.
Optical Received Approx. Forward Approx. RF
Input Level Power @ T.P T.P. Level Output Level
 -8dBm .16V -6dBmV 14dBmV
 -6dBm .25V -2dBmV 18dBmV
 -4dBm .40V 2dBmV 22dBmV
 -2dBm .63V 6dBmV 26dBmV
 0dBm 1.0V 10dBmV 30dBmV
 +2dBm 1.58V 14dBmV 34dBmV

6 FOCN
InstructionManual
Internal Adjustments
TheFOCNreceiverhastwouseradjustmentsinsidetheunit.OneisusedtochangetheForwardReceiveleveltestpoint
calibrationbetween1310nmand1550nmopticalinputranges.TheotheristosettheOMIofthereturnbandtransmit-
ter,(ifequipped)thiswillbediscussedlateron.Theunitshouldnotbeoperatedforextendedperiodswiththetopcover
removed.ThisisbecauseofRFingressandcontaminationfromdirtorotherobjects.Whenreplacingthetopcover,be
suretofirmlytightenallthumbscrews.RFingressoroscillationcanbecausedbyloosescrews.
Thelocationsoftheinternaladjustmentsareshowninthefollowingdiagram.
Return Transmitter Setup
ThespecificationforthereturnbandtransmitterRFinputlevelis-58dBmV/Hz(measuredatFOCNRFOutPort).This
valueoperatesthesystematNPRthreshold.TheFOCNhasanadjustableattenuatorinthereturnpath.Alsoincluded
isa-20dBtestpointinthereturnpath.Thesinglecarrierequivalentof-57dBmV/Hzis+9dBmV.Thereturnpadmust
beadjustedtosetthecarrierto+9dBmVactualaftertheattenuator.Withatestcarrierpresentattheport(+19dBmV
max),measureitslevelatthereturn-20dBtestpoint.Adjustthepadfora-20dBtestpointreadingof-11dBmVreturn
input.
External Test Points
TheFOCNhasthreeexternaltestpoints.Thereceived“OpticalPower”testpointiscalibratedat1VpermW@1310
nm,itshouldbemeasuredwithahighimpedancevoltmeter.Thistestpointisforlongtermmonitoringpurposesas
wellasinitialsetup.Theopticalpowershouldbemeasuredwithapowermeteratthetimeofinstallation.Theinput
testpointiscalibratedatthefactoryat1310nm.Thevalueat1550nmmaybeoffby15%duetodiodevariations.The
inputtestpointreadingwillbeconsiderablyoffiftheinputwavelengthis1550nmandtheinternaljumperhasnot
beenchanged.Thejumperislocatedinsidetheunitnexttothereceiveleveltestpointasshownabove.Theposition
closesttothetestpointisfor1310nm,andthepositionfartherfromthetestpointisfor1550nm.
TheForwardTestPointis-20dBfromtheRFoutputofthereceiver.IftheRFoutis+28dBmV,thenthetestpointshould
beapproximately+8dBmV.
TheReturnTestPointis-20dBfromtheRFinputgoingtothereturntransmitter.Optimalinputshouldbe+14dBmV,so
thetestpointshouldread-6dBmV.

7
FOCN
InstructionManual
System Setup & Trouble Shooting
FiberLossat1310nmis0.330dBperkilometer,and1550is0.188dBperkilometer.Usingthisformula,ifthefiberrun
is6kilometers(3.73miles),thena2dBmtransmitterisrequiredforthedistance.Iftheforwardbandisbeingsplit,then
theadditionallossmustbeaccountedfor.Afibersplittergenerallysplitsthesignalequallybetweeneachoutput.Ifthe
forwardpathistobesplit4ways,thenatransmitterwithanoutputpowerof8dBmwillberequiredtotravelthe6
kilometers.Ifthelinkscomingoutofthesplitteraredifferentlengths,thenbesuretohaveenoughtransmittingpower
toreachthereceiverwiththelongestlink.Thosewithshorterlinkscanbeattenuatedtolowerthesignaltoalevelthe
receivercanuse.Tobesurethereceiverisinthecorrectrange,usetheReceiveTestPointusingahighimpedancemul-
timeter.TheoptimumrangefortheFOCNis0.5VDCto0.9VDC(approx.-3dBmto-0.5dBm).Operationdownto-8dBm
isfeasiblewithreducedperformance.
IftheFiberrunislessthanafewkilometers,thentheopticalsignalmustbeloweredbeforethesystemcanoperatecor-
rectly.Failuretolowerthesignalintotheoperatingrangeofthereceivermaycauseanoverloadedordistortedpicture.
Theeasiestwaytolowerthesignalistouseanopticalattenuator.
Ifthesignalgettingtothereceiveristolow,butthecorrectpowertransmitterisbeingused,pleasecheck
thefollowing:
1:Besurethefiberconnectorsareallofthesametype.AllFOCNunitsareshippedwithSC/APCstyleconnectors.
Thesewillbegreenincolor.YoucanNOTmixgreenandblueconnectors,astheendterminationsaredifferent.Thiscan
alsoresultinlowsignalorsnowypicture.STconnectorsaregenerallyorange,theseareforusewithMultiMode,and
arenotappropriateforbroadbanduse.
2:BroadbandRFtransmitterssuchasthosemadebyBlonderTonguerequiretheuseofSingleModefiber.MultiMode
fiberwillnotwork.AttemptingtouseMultiModefiberwillresultinlowsignalorsnowypicture.

8 FOCN
InstructionManual
MAINTENANCE INSTRUCTIONS
Cleaning
Iftheunitsneedtobecleaned,avoidtheuseofallsolventsanduselow-pressurecleanairtoremoveloosedirt.
Uselow-pressurecleanairtocleartheconnectorsofanydebris.Dirtyorscratchedconnectorendfaceswillgreatly
reducetheunit’sperformance.Foam-tippedswabssuchasthe2.5mmMiniFoamSwabofferedbyFiberInstrument
Sales(P/NF1-0005)maybesaturatedwithdenaturedalcohol*andinsertedintotheopticalportforcleaning.DONOT
INSERTADRYSWABINTOTHEOPTICALPORTASTHISMAYDAMAGETHEFIBERENDFACE.Manyfiberopticinstallations
experiencedegradedperformanceduetodirtyopticalconnectorendfaces.Thefollowingprocedureshouldbeusedto
properlycleantheopticalconnectorendfaces.
Connector Cleaning
Required Cleaning Equipment:
• Kimwipes®oranylens-grade,lint-freetissue.Thetypesoldforeyeglassesworkquitewell.
• DenaturedAlcohol.*
 *NOTE: Useonlyindustrialgrade99%pureisopropylalcohol.Commerciallyavailableisopropylalcoholisfor
medicinaluseandisdilutedwithwaterandalightmineraloil.Industrialgradeisopropylalcoholshould
beusedexclusively.
• 30XMicroscope.
• CannedDryAir.
Directions for Cleaning:
1) Foldthetissuetwicesoitisfourlayersthick.
2) Saturatethetissuewithalcohol.
3) Firstcleanthesidesoftheconnectorferrule.Placetheconnectorferruleinthetissue,andapplypressuretothe
sidesoftheferrule.Rotatetheferruleseveraltimestoremoveallcontaminationfromtheferrulesides.
4) Nowmovetoacleanpartofthetissue.Besureitisstillsaturatedwithalcohol,anditisstillfourlayersthick.
Putthetissueagainsttheendoftheconnectorferrule.Putyourfingernailagainstthetissuesothatitisdirectly
overtheferrule.Nowscrapetheendoftheconnectoruntilitsqueaks.Itwillsoundlikeacrystalglassthathasbeen
rubbedwhenitiswet.
5) Usethemicroscopetoverifythequalityofthecleaning.Ifitisn’tcompletelycleanrepeatthestepswitha
cleantissue.
6) Matetheconnectorimmediately!Don’tlettheconnectorliearoundandcollectdustbeforemating.
7) Aircanbeusedtoremovelintorloosedustfromtheportofatransmitterorreceivertobematedwiththe
connector.Neverinsertanyliquidintotheports.
Connector Handling
1) NEVER TOUCH THE FIBER END FACE OF THE CONNECTOR.
2) Connectorsnotinuseshouldbecoveredovertheferrulebyaplasticdustcap.Itisimportanttonotethattheinside
oftheferruledustcapscontainsastickygelatinousresiduethatistheby-productofthemakingofthedustcap.This
residuewillremainontheferruleendafterthecapisremoved.Thereforeitiscriticalthattheferruleendbecleaned
thoroughlyBEFOREitismatedtotheintendedunit.

9
FOCN
InstructionManual
Notes

10 FOCN
InstructionManual
Notes