User's Manual

1/28/2015 LMU42x0Hardware&InstallationGuidePULSWiki
https://puls.calamp.com/wiki/LMU42x0_Hardware_%26_Installation_Guide 32/47
ExamplesofgoodandpoorGPSantennaplacements
ThereceivedsignallevelsattheGPSantennafromthesatellitesareverylowinpower(approximately136
dBm),soanyblockageoftheantennacanaffectthequalityofthelocationcomputedbythereceiver.Kinksor
tightknotsintheantennacablecanalsopreventtheGPSreceiverfromoperatingproperly.Whenlayingout
theantennacable,careshouldbetakensothatthecableisnotsubjectedtocrushingorstrain.
PlacementofCombinationandInternalAntennas
Whendealingwithcombinationantennas,itismoreimportanttoconsideredGPSperformanceoverComm
performance.GPSsignalstrengthsaremuchlowerthanthosetypicallyseenbycellularnetworkssupportedby
theLMU.InordertomaximizetheperformancetheLMUshouldhaveaclearviewoftheskyaspossible.
WheninstallingtheGPSantennainavehicle,makesurethatthereareasfewobstructionsaspossiblecloseto
theLMUthatmightblocktheview360°tothehorizon.AswithstandaloneGPSantennas,nothingshouldnot
blockthecombinationantennabeyond5°abovethehorizonwiththebestlocationbeingnearthecenterofthe
roof.Formorecovertinstalls,directlyunderthefrontorrearwindshieldsarealsoacceptable.
ExamplesofGood(Green),OK(Yellow)andPoor(Red)comboantennaplacements