Sea Tel 6003A User manual

Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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Document No
135301 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 

1. BriefSummary:
Troubleshootingdocumentfordiagnosingafaultwithandreplacingthepolpotonthe6003A/6004seriesantennas.
2. Checklist:

VerifyRangeofMotion
VerifyPotFeedback
MeasureResistance
3. TheoryofOperation:
Apolangpotentiometerisusedtoprovideafeedbackreferenceforthepositionofthefeedassemblyforlinear
polarization.Thepotactsasapotentialdividergivinganoutputvoltagewhichvariesfrom0Vdcto5Vdc.ThePCU
convertsthevoltageoutputfromthepotintothenumericalvaluedisplayedontheDAC.Afailurewiththepotcausingit
tooutputanincorrectvoltagewillresultinthefeedassemblynotbeingalignedcorrectlycausingbadcrosspolisolation.
Oneindicationthatthereisafaultwiththefeedalignmentofthesystemisthatthetargetlightwillbepermanently
illuminatedontheDACandtheantennawon’ttargetcorrectly.Itwillsit8degreesaboveorbelowthesatellites
elevationlookangle,aspartoftheantennastargetingprocedureistotarget8degreesaboveorbelowthesatellite,
calculatetheautothresholdsettingbasedonthenoisefloorlevelandthenalignthefeedforthecorrectreception
positionbasedonthevesselsGPSpositionandthelookuptableintheDAC.
Ifthesystemisunabletodrivethepolmotortoobtainthecorrectfeedback,orifthepothasfailedandwon’tgivethe
correctfeedback,theantennacan’tcompletethetargetprocessandtheantennawillstayinthisposition.Settingthepol
typeto“0009”willmaketheantennatargetbyremovingtheautopolfunctionfromthetargetingprocess;howeverthe
mis‐alignmentofthefeedwillcausebadcrosspolisolation.
4. VerifyRangeofMotion:
FirstverifythesettingsintheDACarecorrect;thepolscaleshouldbesetto0090togivethefeed180degreesofmotion.
Thedefaultpoloffsetis0030(howeverthesemayhavebeenmodifiedslightlyto“trim”thepolangle).Ensuretrackingis
offthendrivetheelevationto0degreestomakeiteasiertoviewthefeedassemblyfordiagnosticpurposes.
Setthepoltypeto“0009”tosetthemodeofthepolassemblyfromautomatictomanual.Nowenterthepolwindowand
holdthedownarrowtodrivethefeedassemblyintoitsendstop.Atthelowerendoftherangethepolcountshouldbe
approximately28,atwhichpointtheLNBshouldbehorizontalwiththecoaxcablespointingtowardstheleftwhenview
facingthefeedassembly.Attheupperendoftherangethecountshouldbeapproximately210andtheLNBshouldhave
moved180degrees,i.e.thecoaxcablesarenowpointingtotheright.
IfnopolmotordriveispresentverifythepolreadingontheDACisn’toutofrange(i.e.displayingavalueofeither0or
255).Ifoneofthesevaluesaredisplayedit’spossiblethepotisn’talignedcorrectlyandthatadjustingitmaybringitback
towiththescaletheDACrecognizes.Backthepotofffromthemaingearandrotatethepot,verifyingthatthefeedback
valuechangesontheDAC.Ifso,calibratethepolpotandverifyoperationasdescribedinthelaterstagesofthis
document.IfthepolcountontheDACdoesn’tchangewhenthepotisadjustedthepothasfailedandisoutputtinga
defaultvalue.SeeVerifyingtheResistanceofthePolPotsectionbelow.Ifthisisthecasenodrivewillbeissuedtothe
polmotorasthevalueisoutoftherangewhichthesystemoperatesin.
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Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 
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5. VerifytheResistanceofthePolPot:
Thepolangpotentiometer(polpot)consistsofaninternalslideraswellasaCWandCCWcontact.Toverifythe
resistanceofthepotamultimetercanbeusedtomeasurebetweenthesliderandoneofthewiperswhilstrotatingthe
shaftthroughitsrangeandverifyingthe0–5kohmsmeasuredcorrectly.DisconnectJ1frommotorterminationPCB
assembly.

Lookingdownontotheshaftofthepotrotateitclockwiseuntilitreachesitsendstop.

1.NowmeasuretheresistancebetweenthesliderandtheCCW
contact(greycable,pin2ontheIDCconnectorandthebrown
cablepin1ontheIDCconnector).
Thefeedbackshouldbeapproximately5kohms.


2.Nowslowlyrotatetheshaftofthepotcounterclockwise,the
readingshouldcountdownsequentially.Afteroneandahalfturns
thepotwillbeinthecenterofitsrangegivingaresistanceof
approximately2.5kohms.


3.Continuetorotatethepotuntilthecounterclockwiseendstop
(itwillnowhaveturnedthroughall3rotationsofitsrange),the
resistanceshouldbeapproximately0ohms.

Leavingthepotatitscounterclockwiseendstopmeasurebetweentheclockwisecontactandtheslider(greycable,pin2
ontheIDCconnectorandtheredcablepin3ontheIDCconnector),theresistanceshouldbereversedfromtheprevious
rotation,reading5kohms.Rotatingtheshaftofthepotclockwiseshouldreducetheresistancethroughitsrangeto0
ohms.Anyerrorwiththepotnotgivingthecorrectresistanceisanindicationthepotisdefectiveandneedsreplacing.
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Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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consent of Sea Tel, Inc. 
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6. ReplacingthePolPotAssembly:
6.1. Tools.

Snips/Cutters
#1PhillipsScrewdriver
1/16”AllenWrench/Key
TieWraps/cableTies
6.2. Procedure.
Procedureforreplacingthepolpotassembly,SeaTelkitpartnumber:124109‐1(polpotpartnumber:115425‐3).

*CAUTION:Powerdownthepedestalbeforefollowingthis
procedure.
1.Usingapairofsnips,cutthetiewrapswhichsecurethepol
potharnessanddisconnectthepolpotIDCconnectorfromthe
motorterminationPCB.



2.Usinga#1Phillipsscrewdriverremovethetwoscrews
attachingthepolpotbrackettothefeedandremovethepolpot
assembly.



3.Installthereplacementpolpotontothebracketwiththewires
exitingtotheupperrightsideofbracketasonthedefectivepol
potassemblyandsecureitinplaceusingthenutandlock
washer.
4.Installthenewpulleyonthereplacementpotinthesame
positionasonthedefectivepot(itmaybeadvisabletotrialfit
thepotassemblytothefeedtoverifythecorrectpositionofthe
pulleyandpotharness).OncesatisfiedapplyLoctite638tothe
potpulleyandinstallthesetscrewwithLoctite222andtighten
usinga1/16”Allenwrench.
*Note:ForfurtherinformationrefertotheLoctiteProcedure
121730providedwiththiskit.

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Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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consent of Sea Tel, Inc. 


5.ApplyLoctite242tothethreadsonthefeedandinstallthe
polpotassemblylooselyasshownhere,donotengagethe
pulleyontothemaingearatthistime.
7.Followthecalibrationprocedureofthepotoverleaf,tosetits
range.



8.Oncecalibratedengagethepolpotpulleywiththemain
sprocket,verifythepolreadingontheDACiscorrectand
tightenthemountingscrews.


9.ConnecttheIDCconnectiontotheterminationblockand
securetheharnesswithcableties.
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Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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7. PolPotAlignmentandVerification:

1. DrivethereflectortozerodegreesofelevationtoviewtheorientationoftheLNB:
Pressthebuttontoturnthetrackingfunctionoff(ifapplicable)topreventtheantennafromgoingintoa
search.Pushthebuttonuntilthe‘Antenna’windowisdisplayed(thescreenwillshowtheAZ,ELandREL
values).Pressthebuttontwicetoisolatethe‘EL’windowandthenpressthearrowtoactivateit(acursor
willbedisplayed).Nowusetheandarrowkeystoscrollthecursoralongandusethe andarrowkeys
tochangetheelevationvalueto“00.0”andpressthebutton.

2. SetthePolTypetomanualmode:
Enterthe‘SetupMenu’bypressingandholdingthearrowkeystogetheruntilthe“ELTrim’or‘AutoTrim’
windowisdisplayed.Pushthearrowkeyuntilthe‘PolangType’windowisdisplayed.Pressthearrowkeyto
activatethewindow.Nowusetheandarrowkeystoscrollthecursoralongandusetheandarrow
keystochangethecharacters.Setthe‘PolangType’to“0009”whichismanualmodeandpressthebutton.

3. Pressthebuttontogotothe‘PolOffset’windowandverifythedefaultsettingis“0030”.(Ifnecessaryuse
arrowkeystoselectappropriatedigitsandchangeaccordingly).

4. Nowkeeppressingthebuttonuntilthe‘Antenna’windowisdisplayed(thescreenwillshowtheAZ,ELand
RELvalues).
5. Pressthebutton4timesuntil‘Polxxx’isdisplayedandthenpressthearrowkeytoactivatethewindow.

6. Nowholdeithertheorarrowkeytodrivethepoluntilacountof“115”isdisplayed.
*Note:It’sadvisabletohavesomeonewatchingthefeedwhileit’sbeingdrivenasifthepotisn’tcorrectly
calibratedthereisthepossibilitytodamagetheassemblyiftheLNBhitsthepolmotor.

7. ObservethephysicalalignmentoftheLNB:
TheLNBshouldbealignedverticallywiththecoaxcablespointingdownwards,asshownbelow(usethelowerfeed
strutasaguide).Ifnotcontinueontostep8,otherwiseskipaheadtostep13.
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Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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consent of Sea Tel, Inc. 
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

(Steps8‐12requiresassistancetoobserveandoperateantennasimultaneously)
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8. UsingtheDAC‐2202drivethefeedassemblytovertical:
Pressthearrowkeytoactivatethecursoronthepolwindow.Nowholdeithertheorarrowkeytodrive
thepolmotoruntiltheLNBisalignedverticallywiththecoaxcablespointingdownwards(usethelowerfeedstrut
asguide).Nowpressthebuttontode‐activatethewindow.
9. Locatethepolpotonthefeedandloosenthescrewthatsecurestheslottedmountingplate(fig.1.1)andcarefully
movethepolpotgearoutofalignmentwiththemaindrivesprocket(Fig.1.2).


(Fig.1.1)(Fig.1.2)
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10. Alignthepotentiometer:
OntheDACverifythecursorisnotdisplayedonthepolwindow,ifitispressthebutton(Fig1.3)failuretodo
thiswillresultinthedisplaynotchanging.Nowrotatethepotmanuallyuntilacountof115isachieved.Now
reinstallthepotonthemainsprocket(Fig1.4).
*Note:Whenre‐installingthepotontothemainsprocketitscommonforthereadingtochangeastheteethofthe
sprocketsareengaged.Becauseofthisthetoleranceis+/‐2degreesso113‐117counts.


Field Service Procedure – Replacement Pol Pot Kit, 6003A/6004
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Page7of7
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Document No
135301 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 


(Fig1.3)     (Fig1.4)
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11. Drivethepolmotortoitsupperandlowerelectricallimitsandverifytheassemblydrivesinthecorrectdirectionand
thatthefeedassemblyhas180degreesofrotation:
OntheDACpressthe arrowkeytodisplaythecursorunderneaththepolvalueandthenpressandholdthe
arrowkeytodrivethefeedtoitsupperendstopandverifytheLNBishorizontalwiththecoaxcablestowardsthe
right(thepolreadingshouldbeapproximately211counts).Nowpressandholdthearrowkeytodrivethefeed
toitslowerendstopandverifytheLNBishorizontalwiththecoaxcablestowardstheleft(thepolcountshouldbe
approximately28counts).
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12. SetthePolTypetoAutomatic(autopol):
Pressandholdthearrowkeystogetheruntilthe‘ELTrim’or‘AutoTrim’windowisdisplayed.Pushthe
arrowkeytoscrollthroughthesettingsuntilthe‘PolangType’windowisdisplayedandpressthearrowkeyto
activatethewindow.Nowusetheandarrowkeystoscrollthecursoralongandusetheandarrow
keystochangethevaluefrom“0009”to“0072”andthenpressthebuttontoputthesystembackinto
automaticpolang(autopol)mode.
WatchtheLNBandverifyitreturnstothecorrectreceptionposition(whilethepolmotorisdrivingthetargetlight
willbeilluminatedontheDAC).
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13. SavethesettingsintheDAC‐2202:
Pressandholdthearrowkeystogetherbriefly,“SaveNewParameters”willbedisplayed.Pressthe
arrowkeytoactivatethewindowandthenpressthebutton,“ParametersSaved”willbedisplayedandthe
poltypewillbestoredintheDAC.
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