GE MDS DS-GPA-1 40 Watt RF Amplifier User Manual GPA 1manual RevA 5 2 16 3

GE MDS LLC 40 Watt RF Amplifier GPA 1manual RevA 5 2 16 3

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GPA-1 manual

GEMDSGPA‐1Manual

P/Ndraft

RevA.



GPA-1 manual

TableofContents



1Important Information ............................................................................................................ 3

1.1RF Exposure ................................................................................................................... 3

1.2FCC Approval Notice ...................................................................................................... 3

1.3FCC Part 90 Information ................................................................................................. 3

1.4Product Description ........................................................................................................ 4

1.5Power Control Loop ........................................................................................................ 4

2Interfaces .............................................................................................................................. 5

2.1J101 Control Interface .................................................................................................... 5

2.2J102 RF Output .............................................................................................................. 5

2.3J103 RF Input ................................................................................................................. 5

2.4J104 External/Internal Jumper ........................................................................................ 5

2.5R112 Power Control Adjustment .................................................................................... 6

3Installation ............................................................................................................................. 6

3.1Mounting the Unit ........................................................................................................... 6

3.2Connecting the Unit ........................................................................................................ 6

3.3 Alignment (Setting power output) ...................................................................................... 6

GPA-1B smaller heat-sink option ................................................................................................ 7

GPA-1 standard heat-sink option ................................................................................................ 7

Unit Specifications ....................................................................................................................... 8

4Technical Assistance ............................................................................................................ 8

5Change Log ........................................................................................................................... 8

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GPA-1 manual

1 ImportantInformation

1.1 RFExposure

Professional installation required. The radio equipment described in this guide emits radio

frequency energy. Although the power level is low, the concentrated energy from a directional

antenna may pose a health hazard.

Do not allow people to come closer than 1.8 meters, (5.9 feet) to the antenna when the

transmitter is operating with a unity gain antenna.

This is an RF amplifier, the maximum ERP for this FCC band is 500 watts, this equates to an RF

safety distance of 5.7 meters. For Canada, the maximum ERP is 125 Watts, this equates to a

distance of 3.6 meters.

Please consult the FCC website below for RF safety distances, using different antenna gain

configurations which affect the ERP.

More information on RF exposure can be found on the Internet at:

www.fcc.gov/oet/info/documents/bulletins.



Installation professionnelle requise. L'équipement radio décrite dans ce guide émet de l'énergie

de fréquence radio. Bien que le niveau de puissance est faible, l'énergie concentrée depuis une

antenne directionnelle peut-être poser un danger pour la santé.

Ne laissez pas les gens à se rapprocher de 1,8 mètres, (5,9 pieds) à l'antenne lorsque l'émetteur

fonctionne avec une antenne à gain unité.

Il s'agit d'un amplificateur RF, la P.A.R. maximale pour cette bande de FCC est de 500 watts,

cela équivaut à une distance de sécurité RF de 5,7 mètres. Pour le Canada, la P.A.R. maximale

est de 125 Watts, cela équivaut à une distance de 3,6 mètres.

Veuillez consulter le site de FCC ci-dessous pour les distances de sécurité RF, à l'aide de

configurations de gain antenne différentes qui affectent l'ERP.

Plus d'informations sur l'exposition aux radiofréquences se trouvent à l'adresse Internet :

www.fcc.gov/oet/info/documents/bulletins.



1.2 FCCApprovalNotice

ThisdeviceisofferedasalicensedAmplifierperFCCPart,90.Itisapprovedforuseunderthefollowing

conditions:ChangesormodificationsnotexpresslyapprovedbyGEMDSwillvoidtheuser’sauthorityto

operatetheequipment.

1.3 FCCPart90Information

ForFCCPart90,validfrequenciesare150‐174MHzatupto500WattsERP

GPA-1 manual

Caution; only use authorized antennas that meet the FCC license requirements.

Use of unauthorized antennas, cables, and/or coupling devices not conforming

with ERP/EIRP for outdoor/indoor will void the licensee’s license to operate.

Introduction

TheGPA‐1isanRFpoweramplifierdesignedforuseinthe150‐174MHzfrequencyrangeatupto40

Watts.Itisintendedtoserveasa100%dutycycleamplifierforMDSSD1operatinginpoint‐to‐multipoint

repeaterorbaseapplications.

1.4 ProductDescription

TheGPA‐1poweramplifierconsistsofanRFamplifierandPCBmountedtoaheatsink,withaDCPower

interface,powercontrolinterface,andinput/outputRFconnectionsonthesidewallsofthechassis.DC

powerissuppliedtotheamplifierfromaregulatedandfilteredDCsourcecapableofsupplying10‐16Vdc

atamaximumcurrentof8Amperes.TheDCpowersourceshouldbecurrentlimitedorhaveaprotective

fuseorcircuitbreaker.

1.5 PowerControlLoop

TheGPA‐1amplifieroperatesinINTmode.InInternalmode,afeedbackcircuitwithintheamplifier

controlstheoutputpower.ThesetpointissetbypotentiometerR112,locatedwithintheamplifier.

Further,thePAperformsTX/RXswitchingtoprovidealowlossreceivepathwhennottransmitting.The

TX/RXcontrolisperformedbyRFdetectionwithinthePA.



GPA-1 manual



Figure1–J104andR112Locations

2 Interfaces

2.1 J101ControlInterface

TheJ101ControlInterfaceisintendedtoconnecttothetransceiver’scontrolinterfaceandprovides

keyingandpowercontrolsignals.

Table1–J101ControlCablePinFunctions

PinFunction

Pin13VdcenableTX,low=off

Pin20.7Vdc(variestosetRFpower)

Pin3Notused

Pin4Ground

2.2 J102RFOutput

J102isa50OhmFemaleTypeNconnector.

2.3 J103RFInput

J103isa50OhmMaleTypeN,REVERSEPolarityconnector.ThisRFampisprovidedwithaReverse

PolarityNconnector,tomeettheFCCRFsignalBooster/Amplifierrules.Theconnectorisprovidedsothat

onlyoneRFsignalcanbeinputtotheRFAmp.

ThisamplifierisdesignedtobeonlyusedwiththeGEMDSSD1DataTransceiver.

AtnotimeshallthisamplifierbeusedwithnomorethantheintendedsingleRFinput,anyother

combinationofsignalshallvoidtheFCCtypeapprovalofthisamplifier

2.4 J104External/InternalJumper

J104isajumperblockwith3pins.Shortingpins1and2(EXT)isnotusedfortheGPA‐1.Shortingpins2

and3(INT)enablestheamplifier’sinternalpowerdetectortocontroltheamplifierpoweroutput.Access

tothisjumperblockisviaaholeinthetopcover.

GPA-1 manual

2.5 R112PowerControlAdjustment

R112isusedtoadjusttheRFpoweroutputoftheamplifierininternalandmode.Turnthepotentiometer

clockwiseforhigherpowerandcounterclockwiseforlowerpower.

3 Installation

3.1 MountingtheUnit

TheGPA‐1isdesignedformountinginastandard19–inchrackcabinetusingthe3Upanelprovided.Four

screws(notprovided)arerequiredtoattachthepaneltotheracksides.Thispanelalsoservesasaheat

sinkforthePAmodule,andisnormallymountedwiththecoolingfinsfacingoutward.

3.2 ConnectingtheUnit

Placetheamplifiermoduleinservicebymakingthefollowingcableconnections.



1. Usinglowloss50‐ohmcoaxialcable,connecttheRFInputconnector(J103)totheRFoutput

connectoroftheMDSSD1radio.

2. Usinglowloss50‐ohmcoaxialcable,connecttheRFOutputconnector(J102)tothestation

duplexerorantenna.

3. ForusewithSD1transceiverfollowthesesub‐steps,PWRsetbetween23‐27dBm(inputpower).

Donotuseabove27dBmforGPA‐1input.MoveJumperJ104totheInternalKeyingpositionas

showninFigure1AccesstoJ104isavailablethroughatopcoverventslot.

4. Connect10‐16VdcpowersupplytothePowerconnector(J100).Theleftpinispositive(+);the

rightisnegative(–).

3.3Alignment(Settingpoweroutput)

AdjustingRFPowerOutput

Tocheck/settheamplifier’sRFpoweroutput,proceedasfollows.



1. Connectawattmeter(ratedforuseat150MHz,andatleast40watts)totheamplifier’sRF

outputconnector(J102).

2. Terminatethewattmeterintoa50‐ohm,non‐inductiveload.

3. SetSD1PWR=23dBm

4. ApplyRFdrivefrom150MHzradioandnotetheRFpowerindicationatJ102.

5. Ifnecessary,adjustR112(seeFigure2)withaninsulatedflatbladetooltoachievethedesired

outputlevel.Accesstothiscontrolisavailablethroughatopcoverventslot.

GPA-1 manual



GPA‐1Bsmallerheat‐sinkoption



GPA‐1standardheat‐sinkoption

GPA-1 manual

UnitSpecifications

Table2–UnitSpecifications

ParameterSpecification

OperatingVoltage10‐16Vdc

MaximumCurrentDraw8Amperes@12.5V,40WRFOut.

RFDrivePowerSD1PWR=23dBm

RFOut+40to+46dBm(10‐40watts),adjustable

DutyCycle(GPA‐1model)100%uptofulloutputpower

DutyCycle(GPA‐1Bmodel)100%at2Watts,30%above2Watts

OperatingFrequency150

–

174 MHz*

Mountingstandard19‐inchrackcabinet

ApproximateWeight5.15lbs.

Dimensions(GPA‐1model)5.25”Hx19”Wx2.88”D(13.34Hx48.26Wx7.31Dcm)

Dimensions(GPA‐1B‐model)5.25”Hx7”Wx2.88”D(13.34Hx17.78Wx7.31Dcm)

FCCIdentifierE5MDS‐GPA‐1

NameofGranteeGEMDSLLC

4 TechnicalAssistance

Forassistance,contactususingoneofthefollowingmethods:

Telephone:585.241.5510

FAX:585.242.8369

E‐mail:gemds.techsupport@ge.com

Web:www.gemds.com

5 ChangeLog

VersionDateAuthorChanges

A D.McCarthy Initialrelease

 



GE MDS DS-GPA-1 40 Watt RF Amplifier User Manual GPA 1manual RevA 5 2 16 3

GE MDS LLC 40 Watt RF Amplifier GPA 1manual RevA 5 2 16 3

Users Manual

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