Radio Shack PRO-94 - Understanding Trunking

8/17/2015 EasiertoReadPro94ScannerManual
http://marksscanners.com/94/94.shtml 3/21
DisplayBacklightmakesthescannereasiertoreadinlowlightsituations.
Hypersearchletsyousetthescannertosearchatupto300stepspersecondinfrequencybandswith5kHzsteps,compared
tothenormalsearchspeedof100stepspersecond.
KeyLockletsyoulockthescanner'skeystohelppreventaccidentalchangestothescanner'sprogramming.
BatterySavesavesbatterypowerwhenthescannerdoesnotdetectanytransmissionsformorethan5secondswhileasingle
channelisbeingmonitored.Canbeturnedoff.
BatteryLowAlertwarnsyouwhenbatterypowergetslowbybeepingaboutevery10seconds.
KeyConfirmationTonesthescannersoundsatonewhenyoupressakey,performanoperationcorrectly,andanerrortoneif
youmakeanerror.Canbeturnedoff.
MemoryBackupkeepsthefrequenciesstoredinmemoryforanextendedtimeiftheradiolosespower.
Yourscannercanreceivethesebands:

Frequency
Range
StepSize
(kHz) Mode Band
Frequency
Range
StepSize
(kHz) Mode Band
2929.7 5 FM 10MeterHamBand 406420 12.5 FM FederalGovernment
29.750 5 FM VHFLoBand 420450 12.5 FM 70cmHamBand
5054 5 FM 6MeterHamBand 450470 12.5 FM UHFStandardBand
108
136.975
12.5 AM AircraftBand 470512 12.5 FM UHF"T"Band
137144 5 FM MilitaryLandMobile
806
823.9875
12.5 FM
PublicService"800"
Band
144148 5 FM 2MeterHamBand
851
868.9875
12.5 FM
PublicService"800"
Band
148174 5 FM VHFHiBand
896.1125
956
12.5 FM
UHFHi,33cmHam
Band
216
224.995
5 FM 1.25MeterHamBand 12401300 12.5 FM 25cmHamBand
ScanningTerminology
Contents
Scanningtheprocessofsteppingthroughconventionalchannelsinscanbanks.
Trunktracking(orTrunking)theprocessofsearchingforallactivetalkgroupIDsintrunkedsystems,inscanbanks.
TrunkscanningtheprocessofsteppingthroughprogrammedtalkgroupIDsinIDlists,intrunkedsystems,inscanbanks.
Searchingtheprocessofsearchingforactivefrequenciesinpreprogrammedservicesearchesorthelimitsearch.
ManualModeusedforbrowsing,monitoring,andprogrammingconventionalfrequencies.
TrunkModeusedfortrunkingandprogrammingtrunkingfrequenciesandfunctions.
MonitorModeusedformanuallysteppingthroughandmovingmonitormemories.
RemoteModethemodetheradioisinwhilebeingcontrolledbythecomputer.
UnderstandingTrunking
Contents
Trunkingsystemsletalargegroupof2wayradiousers(orevendifferentgroupsof2wayradiousers)efficientlyuseasetof
frequencies.Insteadofselectingaspecificfrequencyforatransmission,theuser’sradioselectsaprogrammedtrunkingbankin
thesystemwhenthatuserpressestheirPTT(pushtotalk)button.Thetrunkingsystemautomaticallytransmitsthecallonthefirst
availablefrequency,andalsosends(onadifferentfrequencycalledaDataorControlchannel)acodethatuniquelyidentifiesthat
transmissionasatalkgroupID(orjustID.)Sowhenyouaretrunktrackingasystem,youarelisteningtoactiveIDstransmittingin
thesystem(eachusingthefirstavailablefrequencyinthesystem.)Trunkingsystemsingeneralallocateandusefewerfrequencies
amongmanydifferentusers.
Sincethetrunkingsystemmightsendacallanditsresponseondifferentfrequencies,itisdifficulttolistentotrunked
communicationsusingaconventionalscanner.Thesescannersletyoumonitorthecontrolchannelfrequencysoyoucanhear