Bell System Practices Plant Series Assembly instructions

BELLSYSTEMPRACTICES
PlantSeries SECTION502-543-406
Issue1,May1970
AT&TCoStandard
SERVICE
2565LKTELEPHONESETS
1.GENERAL
1.01Thissectionprovidesmaintenanceand
connectioninformationforthe2565LK
telephonesets.Maintenanceinformationwas
formerlyfoundinSection502-525-125.Connection
informationwasformerlyfoundinSection502-525-437
whichisherebycanceled.
2.MAINTENANCE
ReplaceableComponents
2.01Fieldreplaceableitemsarelistedunder
OrderingGuideintheappropriateReference
sectioninDivision502.
Loose Card Retainers
2.02Currentproductionsetsareequippedwith
P-25E803andP-269561cardretainers,which
cannotbeadjusted.
2.03IfP-25E785(MD)cardretainerbecomesso
looseonthefaceplatethatthenumbercard
ordesignationstripslips,theycanbetightened
asfollows:
(1)Removefaceplatefromset.
(2)Removecardretainerfromfaceplate.
(3)Bendthefourarmsoftheretainersothat
morepressurewill beappliedtothenumber
cardanddesignationstrip.Thebendsshould
bemadeapproximately1/2-inchinfromthetabs
ontheendsofthearmsandintheopposite
directionfromthefactorybenttabs.
(4)Installthecardretaineronthefaceplate
andinsertthenumbercardanddesignation
strip.
(5)Installfaceplateontelephoneset.
Note: Ifadjustingthearmsoftheretainer
doesnotresultinsufficientholdingpower,
replacethecardretainer.
Housing
2.04Whenremovingorreplacinghousing,guide
lowerfrontofhousingoverpushbuttons.
Onsetsequippedwithexclusion,pullexclusion
plungeruptoitsoperatedpositionbeforeremoving
housing.Plungershouldalsobeinupperposition
whenreplacinghousing.Withhousinginplace,
operateplungerseveraltimestoinsureproper
operation.
Lamps and Pushbuttons
2.05Replacecrackedpushbuttonsorcollar
assemblies.Plasticpartsmaybecleaned
witha waterdampenedcloth.DONOT USE
SOLVENTS. Lampsshouldbenearassociated
pushbuttonwithcontactsurfacesalignedfor
maximumillumination.
2.06Toreplacedefectivelamp.
(1)Removebuttonandcollarassembly.
(2)GentlyprylampfromsocketwithKS-6320
orangestick.
(3)Replacelamp,makingsurethatcontact
surfaceonlampandsocketmeet.
(4)Replacebuttonandcollarassembly.
Keys—589-Type
2.07Keycontactsmaybecleanedusinga 265C
tool,oradjustedusinga 363tool.When
adjustingsprings:
(a)Thereshouldbea minimumclearanceof
1/64-inchbetweencontactspringsandthose
partsofthekeywhichdonotmakecontact.
(c)AmericanTelephoneandTelegraphCompany.1970
PrintedinU.S.A. Page1

SECTION512-620-100
Fig.1—Typical3-TypeSpeakerphone System,BasicComponents
circuit.Thisavoidsa singingconditionwhile
receiving.
(3)Whenspeechistransmitted,thegainof
thetransmittercircuitincreasestonormal.
Simultaneously,thegainoftheloudspeakercircuit
lowerstoavoidsingingasa resultofthe
increasedtransmittergain.Theamountofthe
gainchangedependsuponthesettingofthe
receivervolumecontrol.Thegainchangeis
smalleratthelower(counterclockwise)settings
andgreateratthehigher(clockwise)settings.
(4)A circuit,referredtoasa switchguard,
utilizesthevoltageacrosstheloudspeaker
toreducethepossibilitythatsurroundingroom
noisewillcausefalseoperationoftheswitching
circuitwhilereceivingspeech.
(5)A predeterminedvoicelevelisnecessaryto
switchfromthereceivingtothetransmitting
condition.Inthepresenceofsteadyroomnoise,
aspecialcircuitautomaticallyraisestherequired
thresholdleveltopreventoperationofthe
switchingcontrolcircuitbythenoise.Talkers
willstillswitchsatisfactorilybecausetheyincrease
theirlevelsundernoisyconditions.
Loudspeakers
2.07External—760A equippedwithR2FKmounting
cord.Consistofpermanentmagnet,dynamic
loudspeakermountedona metalbasewithplastic
housing.
2.08Internal—762A usedwith752-,1752-,and
2752-typepanelsets.Consistsofa P-21F246
speaker,neoprenerubberacousticshield,plastic
cover,and13-inchspade-tippedleads.
Transmitters
2.09External666-typetransmittersconsistsof
anAC1transmitterunit,transistorized
amplifier,etc.The666A(MD)isequippedwitha
T11Amountingcord.The666Bhasa T7Acord.
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ISS5,SECTION512-620-100
2.10 External670Aand671Aareusedinconference
arrangementsof3-typespeakerphone:
670AconsistsofanAC1transmitterunit,
transistorizedamplifier,ON-OFFswitchwith
2-positionONswitchforcontrolofauxiliary
671Atransmitters,volumecontrol,plastic
housing,andT9Amountingcord.
671AconsistsofanAC1transmitterunit
andusedasauxiliarystationinconference
arrangement,encasedina plastichousing;
nocordisprovided.
2.11 InareaswhereR.F.interferenceisa problem,
installa modified666Bor670Atransmitter.
Thesetransmittershavebeenmodifiedbythe
WesternElectricServicecenter.Modifiedunits
areidentifiedbya stamp"MODFORRF"located
nearunitcodestamping.Orderunitsasfollows:
"Transmitter,666Bor670AModifiedperSpecification
X-4200."
2.12Internaltransmittersareallmodular,designed
tobeanintegralpartofthetelephoneset
orconsole.Connectionsaremadethrougha KS-type
connectororreceptacleblockandplugs.Components
aresimilartothoseinexternaltransmitters.
#667B—usedinCALLDIRECTOR®sets
equippedwith590-or650-serieskeys.
#672A—usedin3640and3641CALLDIRECTOR
telephonesets
#673A—usedinnursesconsolein3Ahospital
interphonesystem
0674A—intendedforusein3673A-type
telephoneset
#674B—usein2671-typeCALL-A-MATIC®
telephoneset
0679—usedincurrentproductionCALL
DIRECTORsetsequippedwith635-type
keys.
Power Supply
2.13Powertooperatethe55-typecontrolunits
mustbesuppliedbya 2012Btransformer
(orderedseparately).Duetolowervoltagerating,
a2012Atransformershouldnotbeused.
3.INSTALLATION
3.01Thetelephonesetintendedforusein3-type
speakerphonesystemmustmeetthefollowing
requirements:
(1)Providea setoflineswitchtransfercontacts
todisconnectthespeakerphonewhenthe
handsetislifted.
(2)Rotarydialsetsdialedinanon-hookcondition
mustprovidetwosetsofoff-normal(make)
contactsinthedialforloudspeakerandreceiver
mutingduringdialing.
(3)TOUCH-TONEsetsdialedintheon-hook
conditionmustprovidea setofmakecontacts
(sandt)inthedialcommonswitchtoconnect
linepower(IR)fromthecontrolunittothedial
oscillator.Ifa polarityguardisprovidedthese
contacts(sandt)mustbeisolatedfromthe
oscillatorbythepolarityguard.
3.02Planninganinstallation:
(1)Avoidplacingapparatuswithplasticcovers
orpartsinlocationswhereambienttemperatures
mayexceed140degreesF.
(2)Controlunitchassisispartoftheelectrical
circuitandmustbemountedonaninsulated
surface.
(3)Controlunitcanbelocateda maximumof
100feetfromothersystemcomponents
(transmitter,loudspeaker,etc.)when(Al)leads
areconnectedbetweenboththecontrolunit
andtransmitterandthecontrolunitandthe
telephoneset.
(4)Locatetransformernomorethan100feet
fromcontrolunit.TheACreceptacleshould
notbecontrolledbya switch.
(5)Placeloudspeakerandtransmitterwithin
convenientreachofuserandwithnominal
3feetspacingbetweentheunitsandnotfacing
oneanother.
(6)Thereshouldbenoobstructionsbetween
theuser,loudspeaker,andtransmitter.
(7)Topreventinductiveinterferenceonconference
systeminstallations,usenomorethan30
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SECTION512-620-100
feetofshieldedcablefrommaster670Atransmitter
toauxiliary671Atransmitters.Refertosection
onspeakerphoneconferencesystemforconnections.
(8)Makeconnectionsasshowninappropriate
figuresofthissectionorothersectionsin
Division512forspecifictelephonesetconnections.
3.03The55-typecontrolunitcanbeusedwhere
necessarytocutoffcommonringersor
signalstopreventpickupbyspeakerphone.This
featurecanbeprovidedthroughbreakcontactsof
Klrelayincontrolunit.RefertosectioninDivision
512forspecifictelephonesetinvolved.
D-180196 Kit of Parts
3.04The667Btransmitter,wheninstalledin
certainCALLDIRECTORtelephonesetsis
subjecttopickupofmechanicalspringvibrations
whena heldlinebuttonisreleasedandthe
speakerphonesystemison.Thisvibrationis
transmittedthoughthecontrolunitandbackover
theline.Toeliminatethisconditionthe667B
transmittershouldbereplacedwithonemodified
byWesternElectricservicecenter,orderedas
follows:"Transmitter,667B,ModifiedperD-180196."
3.05Packedwiththemodified667Btransmitter
isa pieceofsplitvinyltubingtobe
assembledtothekeypivotbarspringofthe
telephonesetduringinstallationofthetransmitter.
Note: CALLDIRECTORtelephonesetsmay
beorderedwiththemodificationinstalledby
specifying"ModifiedperD-180196."
4.OPERATION
Note: 3-typespeakerphonesystempermits
normaluseofthetelephonesetfororiginating,
receiving,ortransferringcalls.
4.01Tooriginatea callusingspeakerphone:
(1)DepresstransmitterONbuttonandrelease.
ONlampwillilluminateindicatingspeakerphone
isinthetalkingcondition.Listenfordialtone
transmittedthroughloudspeaker.Telephoneset
handsetisnotlifted(exceptwherehandset
coversdial).
(2)Operatedialoftelephonesetinnormal
manner.
(3)Whencompletenumberisdialed,ringing
tones,busysignals,andcalledpartyanswer
willbeheardfromtheloudspeaker.
(4)Whencalledpartyanswers,transmitterand
loudspeakerareusedtocarryona hands-free
conversation.Adjustvolumelevelasdesired.
Note: Bestoperational resultsareobtained
atthelowestacceptablevolumesettings.
(5)Whenoriginatingcallsfromtelephonesets
whichrequireoff-hookdialing,theON button
mustbedepressedandhelduponcompletionof
dialinguntilthehandsetisrestored.
4.02Toansweranincomingcallusingspeakerphone:
(1)Telephonesetringersignalsanincoming
call.
(2)DepressONbuttonontransmitter.Ringing
istrippedandsystemisautomaticalyconnected
tothelinebythecontrolunit.
4.03Todisabletransmitterwhenitisdesired
nottotransmitconversationintheroomto
adistantparty:
(1)DepressONbuttontofullextentofits
travelandholddownduringentiretime
transmitteristobedisabled.
Note: Withtransmitterdisabledconversation
willnotbetransmittedtothedistantparty,
however,distantpartycanstillbeheardover
theloudspeaker.
(2)Afterprivateconversationiscompletedand
itisdesiredtotransmittodistantparty
again,releaseONbutton.Systemisnowrestored
tofullhands-freecapability.
4.04Toterminatea callonspeakerphone:Depress
OFFbuttonontransmitter.ONlampwill
extinguishandcontrolunitwillberestoredtothe
idlecondition.
4.05Transferringfromhandsettospeakerphone
operation:
(1)Afterdialingorduringa conversationdepress
andholdONbuttonoftransmitter.
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ISS5,SECTION512-620-100
(2)Returnhandsettomounting,andrelease
ONbutton.
(3)Adjustvolumeasrequired.
4.06Transferringfromspeakerphonetohandset
operation.Lifthandsetduringspeakerphone
operationtoautomaticallytransfertohandset
operation.Whenitisnecessarytotransferback
tospeakerphone,referto4.05topreventdisconnect.
Conference Speakerphone Arrangement
4.07The670A(master)transmittermayinitiate
andreceivecallswithorwithoutthe671A
auxiliarytransmittersinthecircuit.Tooperate
withmastertransmitterandauxiliarytransmitters,
turntheONbuttonsothewhitelineisparallel
tothefrontofthetransmitter.Tooperatethe
masterindependently,turntheONbuttonsothe
whitelineisperpendiculartothefrontofthe
transmitter.
4.08Disablingthe670Atransmitteralsodisables
the671Atransmittersiftheauxiliary
transmittersareconnectedtothemastercircuit.
(WhitelineoftheONbuttonisparalleltothe
frontofthetransmitter.)
Tests and Adjustments
5.01Whensystemisinstalledormaintenanceis
performedonanycomponent,makethe
followingtestsofspeakerphoneoperation:
(1)Placea calltothetestdeskandswitchto
speakerphone.
(2)Adjustloudspeakervolumetomoderately
loudlisteninglevelbyturningvolumecontrol
oftransmitterclockwise.
(3)Havetestcenterrepeatthequestion"In
whatsuburbdoesJoelive?"severaltimes.
(4)Ifchoppinessisdetectedinthesentence,
particularyinthefirstb insurburb and
thet inwhat, makeloudspeakeradjustmentper
5.02.
(5)Repeatthistestata highlisteninglevelby
turningthevolumecontroltotheextreme
clockwiseposition.
5.02Analternateloudspeakerconnectionis
providedineach55-typecontrolunitto
compensateforroomconditionswhichcauses
voice-switchingduringreception.Theeffectof
voice-switchingistochopportionsoftheincoming
speech.Tocompensateforthiscondition,move
loudspeakerlead(SP2)fromterminal33toterminal
24[55A(MD)or55A*Modified]orterminal29to
terminal30(55B).
5.03Ifradiofrequencyinterferenceisexperienced:
(1)In666A(MD)transmitter;placeKS-13814L7
(0.02mf)capicatoracrossterminalsofAC1
transmitterunit,and/orplacea 542Ccapacitor
(0.25mf)betweenterminal9 oftheterminal
stripandoneofthemountingscrewsusedto
securetheprintedwiringboardtothebase.
(2)In667A(MD)or667Btransmitter;soldera
KS-13814L7(0.02mf)capacitorforterminal
BtoterminalD oftheprintedwiringboard
assemblyorgroundthetransmitterunitcaseto
thetransmittermountingplate.
5.04Ifvoice-switchingcausedbyexternalaudible
signalingdevicesisencountered:
(1)Placeaudiblesignalingdevicesawayfrom
transmitterunit,ifpossible.
(2)Lowervolumeofaudiblesignalingdevices
tolevelthatwillnotcausevoice-switching
featuretooperate.
(3)Installaudiblesignalcutoffusingthecutoff
featureof55-typecontrolunit.Usethe
leadstocommonsignalcontrolandcommon
ringerorbuzzercircuitforthiscutofffeature.
Cleaning
5.05Cleanplasticcoversandhousingswithwater
dampenedKS-2423clothequivalent.Donot
usescouringpowdersorcleaners.
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SECTION512-620-100
Fig.2—55-TypeControlUnitConnections
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ISS5,SECTION512-620-100
Fig.3—666A(MD)TransmitterConnections
Fig.4—666BTransmitterConnections
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SECTION512-620-100
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