2.CONNECTINGRECORDPLAYERSCONNECTINGA 75OHMANTENNA
TheMAC1900hasbeenshippedwithshorting
plugsinthephonoinputs.Removetheshorting
plugsonlyfromthejackthatwillbeused.
Connecta cablefromthe"left"channelofa
recordplayerintothe"L"PHONO1 inputjack.
Connecta cablefromthe"right"channelofa
recordplayerintothe"Ft"PHONO1 jack.
PHONO2 isprovidedfortheuseofa second
recordplayer.
Connecta secondrecordplayerinthesame
waytotheL andR PHONO2 INputjacks.
3.GROUNDCONNECTION:
Agroundpostisprovided.Groundsforturn-
tables,recordchangers,tapedecks,etc.should
beconnectedtothispost.Topreventhum,make
surethegroundwiredoesnotmakeanyconnec-
tionstotheshieldsoftheleftandrightprogram
cablesbetweentheprogramsourceandtheMAC
1900.Theleftandrightprogramcablesandthe
groundwirefromthatsourceshouldbewoundor
twistedtogether.
CONNECTINGANFMANTENNA
Oneofthreeantennasystemscanbeused:(1)an
outdoorFMantenna,or(2)a VHF-TVantenna,or(3)
theindoordipolesupplied.
Anoutdoorantennaisrecommendedforoptimum
performanceinallareas.Infringe(outlying)areas,
bestresultswillbeobtainedwitha highlydirectional
FMantennausedinconjunctionwitha rotator.Ro-
tatetheantennauntilthebestreceptionisobtained.
Iftheantennausesa 300ohmlead,connectittothe
300ANT(red)pushconnector.
AVHF-TVantennaisofteneffectivewhenitisde-
signedforbothFMandTVreception.Connectthe
twoleadsfromtheVHF-TVantennatothe300
ANT(red)pushconnector.
CONNECTINGANINDOORDIPOLEANTENNA
Theflexiblefoldeddipoleantenna(300ohm)is
foruseinurbanorhighstrengthsignalareas.
Connectthetwoleadsfromthedipoletothe300
ANT(red)pushconnector.Theflexibilityofthethin
flatwireassemblypermitsittobeplacedundera rug,
tackedbehindthestereo...orplacedinanyother
convenientlocation.Insomecases,itmaybeneces-
saryto"position"theantennaforbestsignalrecep-
tion.Thisshouldbedonebeforeitispermanently
located.
Avoidlocatingtheantennanexttootherwiresor
metalobjects.Thisantennamaynotproveeffective
inhouseshavingmetalsidingormetalfoilinsulation.
Anunbalanced75ohmantennacanbeconnected
totheMAC1900.A "typeF"connectorisusedto
connectthe75ohmcoaxialcabletothebackpanel
FMANT75input.
AMANTENNA
FormostlocalandmoderatelydistantAMrecep-
tionthebuilt-inferriteloopstickantennamaybe
used.TheAMloopstickantennaisona swivelbase.
Itmustberotatedforbestreception.
Betterlongdistantreceptionispossiblewiththe
useofa copperantennawire50to150feetinlength.
Suspendthewireina straightlineashighaspos-
sible.Attachthewireateachendwithsuitableglass
orceramicinsulators.Connecta lead-inwireatany
convenientpointontheantenna.Itisrecommended
thata lightningarresterbeusedwithanoutdoorAM
antenna.Thearrestershouldbewellgroundedtoa
suitablewaterpipeorcopperoraluminumrodsunk
intotheground.
Connectthelead-inwiretotheAMANT(white)
pushconnectorontheantennaterminalstriponthe
backpanel.
CONNECTINGA MAXIMUM
PERFORMANCEINDICATOR
TheMclntoshMAXIMUMPERFORMANCEIN-
DICATORisconnectedtotheTP1 andTP2 jackson
thebackpaneloftheMAC1900.Usetheprocedures
asdirectedintheMAXIMUMPERFORMANCEIN-
DICATORownersmanual.
FUSE
A3.2AMP "SLO-BLO"fuseprotectsthereceiver
circuits.Thisfusedoesnotprotectadditionalequip-
mentconnectedtothebackpanelACoutlets.
ACPOWEROUTLETS
Thereare2 blackandoneredACpoweroutlet.
Thepowertotheblackoutletsiscontrolledbythe
frontpanelACpowerswitchontheVOLUMEcontrol.
Usetheseoutletsfora poweramplifier,ortapere-
corder,etc.Theredreceptacleisonatalltimes.Use
theredoutletfora turntableorrecordchanger.The
turntableisprotectedbythisarrangement.Itisnec-
essarytoturnofftheturntableorrecordchanger
withitsownACpowerswitch.
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