Raymarine axiom 12 - RF Interference; Compass Safe Distance; GPS Location Requirements

Note:InareasofextremeEMCinterference,someslightinterferencemaybenoticedonthe
product.Wherethisoccurstheproductandthesourceoftheinterferenceshouldbeseparated
byagreaterdistance.
ForoptimumEMCperformancewerecommendthatwhereverpossible:
•Raymarineequipmentandcablesconnectedtoitare:
–Atleast1m(3ft)fromanyequipmenttransmittingorcablescarryingradiosignalse.g.VHFradios,
cablesandantennas.InthecaseofSSBradios,thedistanceshouldbeincreasedto7ft(2m).
–Morethan2m(7ft)fromthepathofaradarbeam.Aradarbeamcannormallybeassumedto
spread20degreesaboveandbelowtheradiatingelement.
•Theproductissuppliedfromaseparatebatteryfromthatusedforenginestart.Thisisimportant
topreventerraticbehavioranddatalosswhichcanoccuriftheenginestartdoesnothavea
separatebattery.
•Raymarinespecifiedcablesareused.
•Cablesarenotcutorextended,unlessdoingsoisdetailedintheinstallationmanual.
Note:Whereconstraintsontheinstallationpreventanyoftheaboverecommendations,always
ensurethemaximumpossibleseparationbetweendifferentitemsofelectricalequipment,to
providethebestconditionsforEMCperformancethroughouttheinstallation
RFinterference
Certainthird-partyexternalelectricalequipmentcancauseRadioFrequency(RF)interferencewith
GPS,AISorVHFdevicesiftheexternalequipmentisnotadequatelyinsulatedandemitsexcessive
levelsofelectromagneticinterference(EMI).
SomecommonexamplesofsuchexternalequipmentincludeLEDspotorstriplights,andterrestrial
TVtuners.
Tominimizeinterferencefromsuchequipment:
•KeepitasfarawayfromGPS,AISorVHFdevicesaspossible.
•Ensurethatanypowercablesforexternalequipmentarenotentangledwiththepowerordata
cablesforGPS,AISorVHFdevices.
•ConsiderfittingoneormorehighfrequencysuppressionferritestotheEMI-emittingdevice.The
ferrite(s)shouldberatedtobeeffectiveintherange100MHzto2.5GHz,andshouldbefitted
tothepowercableandanyothercablesexitingtheEMI-emittingdevice,ascloseaspossibleto
thepositionwherethecableexitsthedevice.
Compasssafedistance
Topreventpotentialinterferencewiththevessel'smagneticcompasses,ensureanadequate
distanceismaintainedfromtheproduct.
Whenchoosingasuitablelocationfortheproductyoushouldaimtomaintainthemaximumpossible
distancefromanycompasses.Typicallythisdistanceshouldbeatleast1m(3ft)inalldirections.
Howeverforsomesmallervesselsitmaynotbepossibletolocatetheproductthisfarawayfroma
compass.Inthissituation,whenchoosingtheinstallationlocationforyourproduct,ensurethatthe
compassisnotaffectedbytheproductwhenitisinapoweredstate.
GPSlocationrequirements
Inadditiontogeneralguidelinesconcerningthelocationofmarineelectronics,thereareanumberof
environmentalfactorstoconsiderwheninstallingequipmentwithaninternalGPSantenna.
Mountinglocation
•AboveDecks(e.g.openair)mounting:ProvidesoptimalGPSperformance.(Forequipment
withappropriatewaterproofrating.)
•BelowDecks(e.g.enclosedspace)mounting:GPSperformancemaybelesseffectiveandmay
requireanexternalGPSreceiver,mountedabovedecks.
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