Radio Shack PRO-92 owner manual Understanding Your SCANNER’S Modes, Open and Closed Modes

Page 24

UNDERSTANDING YOUR

SCANNER’S MODES

You can program each channel with any of seven re- ceive modes. Each mode affects how your scanner op- erates when scanning and receiving transmissions, and also affects what transmissions you receive when you set the scanner to the closed mode (see “Open and Closed Modes” on Page 57). The following sections de- scribe each mode and how they affect your scanners op- eration. See “Changing the Receive Mode” on Page 45.

PL, DPL and trunking systems all use some form of cod- ed squelch. Coded squelch techniques involve the trans- mission of a special “code” signal along with the audio of a radio transmission. A receiver with coded squelch only activates when the received signal has the correct “code.” This lets many users share a single frequency, and decreases interference caused by distant transmit- ters on the same channel.

In all major metropolitan areas of the United States, ev- ery available radio channel is assigned to more than one user. Public safety radio systems on the same frequency are usually set up at a distance of 40 miles apart, or more. This means that you may hear transmissions from a distant system when your local system is not transmit- ting. By entering the PL for a local system, and operating the bank in closed mode, the scanner will not stop on transmissions from the distant system.

With few exceptions, such as the VHF Aircraft and Ma- rine bands, almost every other VHF or UHF radio system uses some form of coded squelch. By far, PL is the most popular mode among non-trunked systems. For most scanning use, try setting PL mode for all non-trunked channels. If you operate the bank in open mode, the scanner will display the appropriate code.

Open and Closed Modes

You can set your scanner to change the way it receives signals. These settings, called open mode and closed mode, affect how the scanner receives signals from communications systems that use some type of closed squelch (such as PL, DPL, LTR, MOT, and ED systems).

24	About Your Scanner

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Contents PRO-92 Handheld Scanner Contents Special Features OperationTroubleshooting Care SpecificationsTrunking Operation General Guide to ScanningFeatures Scanner scans Features FCC Notice Scanning LegallyPower Sources PreparationUsing Batteries Preparation11 Charging Rechargeable Batteries Replace the coverUsing AC Power Using Vehicle Power PWR DC 9V jackConnecting the Antenna Connecting an Optional AntennaConnecting AN EARPHONE/ Headphones Listening SafelyConnecting AN Extension Speaker Using the Belt ClipTraffic Safety Connecting the Clone Cable About Your ScannerLook AT the Keypad About Your Scanner Look AT the Display 7 are turned off Search Mode Understanding BanksChannel Storage Banks Understanding CTCSS/DCS Search BanksPL Codes DPL CodesUnderstanding Your SCANNER’S Modes Open and Closed ModesAM Mode FM Mode LTR E. F. Johnson ModeMotorola Mode Edacs Mode Turning on the Scanner and Setting Squelch OperationStoring Known Frequencies Into Channels Bank Channel ManualStoring Text Tags Assigning a Text Tag to a ChannelAssigning a Text Tag to a Bank Text Input Chart Press To Enter a Character from this GroupFinding and Storing Active Frequencies Searching a Preprogrammed Frequency RangePress Func 9 w x y zCurrent Search Bank Storing a Frequency While Searching for a Specified Channel Changing a Search Range with a Preprogrammed RangeFunc then Tune Scanning the Channels Manually Changing a Search RangeManually Tuning a Frequency Turning Channel-Storage Banks Off and OnDeleting Frequencies from Channels Listening to the Weather BandListening to a Weather Channel Displaying Weather MessagesSpecial Features Using the Delay FunctionLocking OUT Channels or Frequencies Locking Out ChannelsReviewing the Lock-Out Channels Locking Out FrequenciesReviewing Locked-Out Frequencies Clearing a Locked-Out FrequencyClearing All Lock Out Frequencies in a Search Bank Locked-outPriority Special Features Changing the Receive Mode Changing the Frequency StepDisplay Description Using the Attenuator Range MHz Search Step kHzUsing the Display Backlight Using the KeylockTurning the KEY Tone on and OFF Changing the Display ContrastTrunking Operation Cloning the Programmed Data from Scanner to ScannerUnderstanding Trunking Setting Squelch for the Trunking Mode Programming Trunking FrequenciesProgramming Motorola Trunking Systems UHF-Lo Offset Frequency Programming Fleet Maps Size CodeTalk Group IDS Storing Talk Group IDs Talk Group ID HoldLocking Out Talk Group IDs Reviewing Locked-Out Talk Group IDsClearing Talk Group IDs Clearing All Talk Group IDs in One BankClosed Mode Open and Closed ModesChanging the Open/Closed Mode Mode Open ClosedGeneral Guide to Scanning Guide to Frequencies US Weather FrequenciesHam Radio Frequencies Birdie FrequenciesGeneral Guide to Scanning Guide to the Action Bands Typical Band UsagePrimary Usage VHF BandAbbreviations Services Band AllocationMeter Amateur Band VHF Low Band- 29-50 MHz in 5 kHz stepsMeter Amateur Band- 50-54 MHz Aircraft Band- 108-137 MHzGovernment Band 406-420 MHz Cm Amateur Band 420-450 MHzLow Band 450-470 MHz Frequency Conversion Troubleshooting Problem Possible Cause RemedySquelch is not RESETTING/INITIALIZING the Scanner Resetting the ScannerDC 9V jack Reset CareInitializing the Scanner Specifications UHF T9V DC Specifications71 Limited One-Year Warranty

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