Manual / Guide
Uniden Bearcat BC246T Scanner — Owner's Manual
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Manual / Guide
BC246T OWNER’S MANUAL OWNER’S MANUAL Precautions Before you use this scanner, please read and observe the Precautions following. IMPORTANT! This scanning radio has been manufactured so that it will not tune to the radio frequencies assigned by the FCC for cellular telephone usage. The Electronic Communications Privacy Act of 1986, as amended, makes it a federal crime to intentionally intercept cellular or cordless telephone transmissions or to market this radio when altered to receive them. The installation, possession, or use of this scanning radio in a motor vehicle may be prohibited, regulated, or require a permit in certain states, cities, and/or local jurisdictions. Your local law enforcement officials should be able to provide you with information regarding the laws in your community. Changes or modifications to this product not expressly approved by Uniden, or operation of this product in any way other than as detailed by this Operating Guide, could void your authority to operate this product. EARPHONE WARNING! Be sure to use only a monaural earphone with this scanner. You can also use an optional 32 Ω stereo headset. Use of an incorrect earphone or stereo headset might be potentially hazardous to your hearing. The output of the phone jack is monaural, but you will hear it in both headphones of a stereo headset. Set the volume to a comfortable audio level coming from the speaker before plugging in the monaural earphone or a stereo headset of the proper impedance (32 Ω). Otherwise, you might experience some discomfort or possible hearing damage if the volume suddenly becomes too loud because of the volume control or squelch control setting. This might be particularly true of the type of earphone that is placed in the ear canal. Precautions 2 WARNING! Uniden does not represent this unit to be waterproof. To reduce the risk of fire or electrical shock, do not expose this unit to rain or moisture. Motorola®, SMARTNET®, PL®, Private Line®, DPL®, Digital Private Line®, and PRIVACY PLUS® are registered trademarks of Motorola, Inc. LTR® is a registered trademark of E.F. Johnson Co. EDACS® is a registered trademark of M/A-COM Private Radio Systems, Inc. Uniden® and Bearcat® are registered trademarks of Uniden America Corporation. TrunkTracker™, Trunk Tracking™, and Close Call™ are proprietary trademarks of Uniden America Corporation. Other trademarks used throughout this manual are the property of their respective holders. Precautions 3 Contents Contents Precautions ......................................................................................... 2 Contents .............................................................................................. 4 The FCC Wants You to Know ............................................................ 8 Scanning Legally .............................................................................. 8 Introduction....................................................................................... 10 Feature Highlights ............................................................................ 12 General........................................................................................... 12 About This Manual.......................................................................... 16 How the Scanner’s Controls Are Represented in This Manual... 16 Entering Text ..............................................................................17 Understanding Scanning ................................................................. 18 Understanding the Scanner’s Memory ........................................... 18 What is Scanning?.......................................................................... 18 What is Searching? ........................................................................ 19 What is CTCSS/DCS?.................................................................... 19 Conventional Scanning................................................................... 21 Simplex Operation ...................................................................... 21 Repeater Operation .................................................................... 22 What is Trunk Tracking?................................................................. 22 Trunked Scanning .......................................................................... 23 Types of Trunking Systems ............................................................ 24 Motorola Trunking....................................................................... 24 EDACS Trunking .........................................................................25 LTR Trunking .............................................................................. 26 I-Call (Motorola/EDACS) ................................................................ 27 Where To Get More Information..................................................... 27 Included With Your Scanner............................................................ 29 Setting Up Your Scanner ................................................................. 30 Using Internal Batteries .................................................................. 30 Using Rechargeable Batteries........................................................ 32 Removing the Display Sticker......................................................... 33 Using AC Power ............................................................................. 33 Connecting the Antenna ................................................................. 33 Connecting an Optional Antenna................................................ 33 Connecting an Earphone/Headphone ............................................ 34 Connecting an Extension Speaker ................................................. 34 Attaching the Belt Clip .................................................................... 34 Attaching the Wrist Strap................................................................ 34 Installing the Demo Software.......................................................... 35 A Look At The Keypad.................................................................... 35 A Look At The Display .................................................................... 38 Using Menu .................................................................................... 39 Using Func ..................................................................................... 39 Using the Scroll Control.................................................................. 39 Basic Operation ................................................................................ 40 Turning On the Scanner and Setting the Squelch .......................... 40 Scanning Systems.......................................................................... 40 Preprogrammed System Tips ..................................................... 41 Contents 4 Selecting Systems to Scan ............................................................ 41 Selecting System Channel Groups ................................................ 42 Locking/Unlocking Systems........................................................... 42 Locking/Unlocking Channels ......................................................... 42 ID Scan/ID Search Mode ............................................................... 43 Temporarily Holding On a System................................................. 43 Holding On a Channel ................................................................... 43 Quickly Storing an ID During ID Search ........................................ 43 Quick-Storing Channels or Talk Group ID’s................................... 43 Quickly Recalling Channels ........................................................... 44 Monitoring Trunking Activity........................................................... 44 Using the Menu ................................................................................ 45 Other Settings .................................................................................. 47 Displaying System Information ...................................................... 47 Viewing Memory Used ............................................................... 47 Viewing the Firmware Version ................................................... 47 Adjusting the Key Beep ................................................................. 47 Locking/Unlocking the Keypad ...................................................... 47 Turning Power Save On or Off ...................................................... 47 Priority Scan .................................................................................. 47 Using the Backlight ........................................................................ 48 Initializing the Scanner’s Memory .................................................. 48 Using the PC Control and Cloning Options ................................... 49 Connecting Your Scanner to a Personal Computer ................... 49 Cloning the Scanner................................................................... 50 Programming Radio Systems......................................................... 51 Programming Conventional Systems ............................................ 52 Entering/Editing Conventional Channel Groups......................... 52 Entering/Editing Conventional Channels.................................... 53 Programming Motorola Systems ................................................... 53 Setting System Frequencies ...................................................... 55 Entering/Editing Motorola Channel Groups................................ 55 Entering/Editing Motorola Channels........................................... 56 Programming EDACS Systems ..................................................... 57 Setting System Frequencies ...................................................... 58 Entering/Editing EDACS Channel Groups ................................. 58 Entering/Editing EDACS Channels ............................................ 59 Programming LTR Systems........................................................... 59 Setting System Frequencies ...................................................... 60 Entering/Editing LTR Channel Groups....................................... 60 Entering/Editing LTR Channels/Talkgroups ............................... 61 Programming/Editing Optional Settings........................................ 62 System-Level Settings ................................................................... 62 Editing the System Name........................................................... 62 Editing the System Quick Key.................................................... 62 Setting System Lockout ............................................................. 63 Setting the System Hold Time.................................................... 63 Setting the Channel Delay Time ................................................ 64 Setting ID Scan/Search (Trunked Systems Only) ...................... 64 Setting the Base Freq/Step/Offset (Motorola UHF/VHF Sys Only) 65 Contents 5 Setting Data Skip(Conventional Systems Only) ......................... 65 Editing the Fleet Map (Motorola Systems Only) ......................... 66 Setting the Motorola Status Bit (Motorola Systems Only)........... 67 Setting the End Code Operation (Motorola Systems Only) ........ 67 Setting I-Call (Motorola and EDACS Systems Only) ...................68 Setting Emergency Alert (Motorola and EDACS Systems Only) 68 Setting the EDACS ID Format (EDACS Systems Only) ............. 69 Setting Control-Channel Only (Motorola Systems Only) ............ 69 Setting System Attenuation (Trunked Systems Only)................. 70 Deleting Systems........................................................................ 70 Copying Systems........................................................................ 70 Group-Level Settings...................................................................... 71 Entering/Editing the Group Name............................................... 71 Setting the Group Quick Key .......................................................71 Setting Group Lockout ................................................................ 72 Deleting Groups.......................................................................... 72 Channel-Level Settings .................................................................. 73 Editing the Channel Name.......................................................... 73 Setting Channel Priority (Conventional Channels Only) ............. 74 Setting Channel Alert.................................................................. 74 Setting CTCSS/DCS (Conventional Channels Only).................. 75 Setting Channel Modulation (Conventional Channels Only)....... 76 Setting Channel Attenuation (Conventional Channels Only) ...... 76 Setting the Frequency Step (Conventional Channels Only) ....... 77 Setting Channel Lockout............................................................. 77 Deleting Channels ...................................................................... 78 Copying/Pasting Channels ......................................................... 78 Searching and Storing ..................................................................... 80 Service Search ............................................................................... 80 Quick Search .................................................................................. 81 CTCSS/DCS Search ...................................................................... 81 Custom Search............................................................................... 81 Editing a Custom Search Range ................................................ 82 Auto Search and Store ................................................................... 83 Selecting a System ..................................................................... 84 Storing a Conventional System .................................................. 84 Storing a Trunked System .......................................................... 85 Using the Close Call Feature........................................................... 86 Setting Close Call Options.............................................................. 87 Close Call Hits ................................................................................ 88 Search and Close Call Options ....................................................... 89 Managing Locked-Out Frequencies ............................................... 89 Unlocking All Frequencies .......................................................... 89 Reviewing Locked Out Frequencies ........................................... 89 Searching for Subaudible Tones .................................................... 89 Screening Out Paging Systems...................................................... 90 Screening Out UHF TV Systems.................................................... 90 Finding Repeater Output Frequencies ........................................... 91 Setting the Maximum Auto Store Value.......................................... 91 Setting the Modulation Type........................................................... 91 Contents 6 Setting Attenuation ........................................................................ 92 Setting Data Skip ........................................................................... 92 Setting the Delay Time .................................................................. 93 Setting the Search Frequency Step............................................... 93 Using Weather Alert (SAME)........................................................... 94 Searching For a Weather Broadcast ............................................. 94 Turning Weather Alert On/Off ........................................................ 94 Programming a SAME Group ........................................................ 95 Setting WX Alert Priority ................................................................ 96 Care and Maintenance..................................................................... 97 General Use................................................................................... 97 Location ......................................................................................... 97 Cleaning......................................................................................... 97 Repairs .......................................................................................... 97 Birdies............................................................................................ 97 Troubleshooting............................................................................... 98 Specifications ................................................................................ 101 Optional Accessories ................................................................... 102 Appendix ........................................................................................ 103 Preset Fleet Maps........................................................................ 103 User Defined Fleet Maps ............................................................. 105 Type I Programming Information ............................................. 105 Size Code Restrictions............................................................. 106 Planning.......................................................................................... 107 Collecting Information .................................................................. 107 Filling Out The Conventional System Worksheet ........................ 108 System Name and Quick Key .................................................. 108 Group Name and Quick Key .................................................... 109 Frequency-Alpha Tag-Priority-CTCSS/DCS ............................ 109 Filling Out The Motorola Worksheet ............................................ 109 System Name and Quick Key .................................................. 109 System Type ............................................................................ 109 System Frequencies ................................................................ 110 Fleet Map (Type I or Type I/Type II Hybrid Only)..................... 110 Band Plan (VHF or UHF Only) ................................................. 110 Group Name and Quick Key .................................................... 110 Talk Group ID-Alpha Tag-Alert................................................. 111 Filling Out the LTR and EDACS Worksheet ................................ 111 System Name and Quick Key .................................................. 111 System Frequencies and LCN ................................................. 111 Group Name and Quick Key .................................................... 111 Talk Group ID-Alpha Tag-Alert ................................................. 111 Conventional System Worksheet................................................. 112 Motorola System Worksheet........................................................ 113 LTR/EDACS System Worksheet ................................................. 115 Preprogrammed Systems .............................................................. 116 One-Year Limited Warranty........................................................... 126 Contents 7 The FCC Wants You to Know This beenYou testedto and found to comply with Thescanner FCC has Wants Know the limits for a scanning receiver, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This scanner generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this scanner does cause harmful interference to radio or television reception, which can be determined by turning the scanner on and off, you are encouraged to try to correct the interference by one or more of the following measures: • Reorient or relocate the receiving antenna • Increase the separation between the scanner and the receiver This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: 1) This device may not cause harmful interference, and 2) this device must accept any interference received, including interference that may cause undesired operation. Scanning Legally Your scanner covers frequencies used by many different groups, including police and fire departments, ambulance services, government agencies, private companies, amateur radio services, military operations, pager services, and wireline (telephone and telegraph) service providers. It is legal to listen to almost every transmission your scanner can receive. However, there are some transmissions that you should never intentionally listen to. These include: • Telephone conversations (cellular, cordless, or other private means of telephone signal transmission) • Pager transmissions • Any scrambled or encrypted transmissions The FCC Wants You to Know 8 According to the Electronic Communications Privacy Act (ECPA), you are subject to fines and possible imprisonment for intentionally listening to, using, or divulging the contents of such a conversation unless you have the consent of a party to the conversation (unless such activity is otherwise illegal). This scanner has been designed to prevent the reception of cellular telephone transmissions and the decoding of scrambled transmissions. This is done to comply with the legal requirement that scanners be manufactured so they are not easy to modify to pick up these transmissions. Do not open your scanner’s case to make any modifications that could allow it to pick up transmissions that are illegal to monitor. Modifying or tampering with your scanner’s internal components or using it in a way other than as described in this manual could invalidate your warranty and void your FCC authorization to operate it. In some areas, mobile use of this scanner is unlawful or requires a permit. Check the laws in your area. It is also illegal in many areas (and a bad idea everywhere) to interfere with the duties of public safety officials by traveling to the scene of an incident without authorization. The FCC Wants You to Know 9 Introduction Introduction Your BC246T scanner is a state-of-the-art scanner radio with TrunkTracking™ and automatic scanning capabilities. You can store frequencies such as police, fire/emergency, marine, air, amateur, and other communications into the scanner. You can carry it with you wherever you go, use it at home as a base unit, or install it in your vehicle as a mobile unit. You can use the scanner’s scroll control to quickly select channels and frequencies, and you can automatically program channels in a system using the AutoStore feature. Use your scanner to monitor: • Trunked public safety systems • Police and fire departments (including rescue and paramedics) • NOAA weather transmissions • Business/Industrial radio • Utilities • Marine and amateur (ham radio) bands • Air band • Railroad This table lists the frequency ranges, default frequency step, default mode (AM or Narrowband FM), and type of transmissions you can hear for each range. Frequency Range (MHz) Step (kHz) Mode Transmission 25.0-26.960 5 AM Petroleum/ Broadcast Band 26.96527.405 5 AM Citizens Band Class D 27.41027.995 5 AM Business Band 28.0-29.680 20 NFM 10 Meter Amateur Band Introduction 10 29.7-49.990 10 NFM VHF Low Band 50.0-54.0 20 NFM 6 Meter Amateur Band 108.0136.9750 25 AM Aircraft Band 137.0143.9875 12.5 NFM Military Band 144.0147.995 5 NFM 2 Meter Amateur Band 148.0150.7875 12.5 NFM Military Land Mobile 150.800161.995 5 NFM VHF High Band 162.0-174.0 12.5 NFM Federal Government 216.0-224.98 20 NFM 1.25 Meter Amateur Band 400.0405.9875 12.5 NFM Miscellaneous 406.0419.9875 12.5 NFM Federal Land Mobile 420.0449.9875 12.5 NFM 70 cm Amateur Band 450.0469.9875 12.5 NFM UHF Standard Band 470.0-512.0 12.5 NFM UHF TV Band 806.0823.9875 12.5 NFM Public Service Band 849.0125868.9875 12.5 NFM Public Service Band 894.0125956.0000 12.5 NFM Public Service Band 1240.00001300.0000 25 NFM 25 cm Amateur Band Introduction 11 Feature Highlights Feature GeneralHighlights Close CallTM RF Capture Technology - you can set the scanner so it detects and provides information about nearby radio transmissions. See “Using the Close Call Feature” on Page 86 for more information. Dynamically Allocated Channel Memory - your scanner’s memory is organized so that it more closely matches how radio systems actually work, making it easier to program and use your scanner and determine how much memory you have used and how much you have left. Preprogrammed Systems - your scanner is preprogrammed with over 400 channels covering police, fire, and ambulance operations in the 25 most populated counties in the US. A complete list of the scanner’s preprogrammed systems is in “Preprogrammed Systems” on Page 116. Quick Keys – You can set the scanner so you can select systems and groups by pressing a single key. This makes it easy to listen to or quickly lock out those systems or groups you don’t want to scan. Pager Screen – You can set the scanner so it ignores hits generated by common pager frequencies while using the Close Call or search features. UHF TV Screen – You can set the scanner so it ignores hits generated by UHF TV frequencies while using the Close Call or search features. Ten Service Searches - frequencies are preset in separate public safety, news, amateur radio, marine, railroad, air, CB radio, FRS/GMRS, racing, and special searches, to make it easy to find specific transmissions. Lockout – You can lock out any system, group, frequency, or channel while scanning. If you lock out a system or group, any channels belonging to that system or group are also locked out. Feature Highlights 12 You can lock out up to 200 frequencies. The scanner skips locked-out frequencies while using the Close Call feature or while searching. CTCSS and DCS Squelch Modes – prevent interference from stations not using the mode you select. Dropout Delay – You can set whether the scanner pauses at the end of a transmission to wait for a reply. You can set the delay time for each system you scan, and while searching and using the Close Call feature. Attenuator – You can set the scanner’s attenuator to reduce the input strength of strong signals by about 18 dB received by the scanner. Repeater Reverse – You can set the scanner so it switches to the input frequency on a conventional repeater system. Channel Alert – You can set the scanner so it alerts you when there is activity on any channel you specify. Memory Check – Lets you see at a glance how much total memory is left. Frequency Step – Lets you select a frequency step (5, 6.25, 7.5, 10, 12.5,15, 20, 25, 50 or 100 kHz) for manual mode and chain search mode. The scanner’s auto step feature lets you set the scanner so it automatically chooses the correct step. Quick Recall – Lets you quickly select a specific channel by choosing the system, group, and channel. Scan/Search Delay – You can set the scanner so it remains on a frequency up to 5 seconds after the last transmission to wait for a possible reply. Text Tagging – You can name each system, group, channel, talk group ID, custom search range, and SAME group, using up to 16 characters per name. Unique Data Skip – Allows your scanner to skip unwanted data transmissions and reduces birdies. Feature Highlights 13 Duplicate Frequency Alert – Alerts you if you try to enter a duplicate name or frequency already stored in the scanner. Memory Backup – If power is lost or disconnected, the scanner retains the frequencies you programmed in its memory. 21 Bands – Includes 21 bands, with Aircraft and 800 MHz. Note: The scanner’s frequency coverage is not continuous and does not include the cellular telephone band. Trunk Tracking Trunk Tracker™ Operation – Follows conversations on analog Motorola, EDACS, EDACS SCAT, and LTR trunked radio systems. The scanner can scan both conventional and trunked systems at the same time. Control Channel Only Scanning – If the scanner is set to scan Motorola trunking frequencies, you can set it so it scans using only control channel data. You do not have to program voice channel frequencies into memory in this mode. Weather Weather Search – Lets your scanner receive your local NOAA weather transmission. SAME Weather Alert – Lets your scanner alert you when a SAME weather alert is transmitted on a NOAA weather channel. The scanner also displays the transmitted alert type. This helps you quickly find out about severe weather in your area and lets you avoid false alarms. Search Service Search – Lets you quickly select and search the scanner’s preprogrammed frequencies. Custom Search – Lets you program up to 10 custom search ranges. You can search any of these ranges simultaneously. Feature Highlights 14 CTCSS/DCS Search – Lets the scanner search for CTCSS or DCS tones. You can identify up to 50 CTCSS tones and 104 DCS tones. Quick Search – Lets you search from the currently-tuned frequency if you are searching a conventional system. Auto Store Frequency AutoStore – Automatically stores all active frequencies within a system you select. Talk Group ID AutoStore – Automatically stores all new talk group ID’s into a system you select. Priority Priority Scan – Priority channels let you keep track of activity on your most important channel(s) while monitoring other channels for transmissions. Priority Plus – You can set the scanner so it scans only the priority channels Backlight and Power LCD Back Light – Makes the display easy to see in dim light. You can adjust the back light so it turns on when you press a key, when squelch breaks during a transmission, or manually. Low Battery Alert – The scanner alerts you if the batteries need to be recharged or replaced. Battery Save – You can set the scanner so it reduces the amount of power it needs if there are no transmissions. Key Controls Key Lock – You can deactivate the scanner’s keys to help prevent accidentally changing the scanner’s programming. Feature Highlights 15 PC Control and Cloning PC Control – You can transfer programming data to and from your scanner and your personal computer, and control the scanner using a computer. This helps you find frequencies listed on the Internet and load them into the scanner. Clone Mode – You can clone all programmed data, including the contents of the scanner’s memory, menu settings, and other parameters from one BC246T scanner to another BC246T scanner. About This Manual The screen displays used in this manual are representations of what might appear when you use your scanner. Since what you see depends on the frequencies and user ID’s for your area and the settings you select, you might notice some differences between what is in this manual and what appears on your scanner. How the Scanner’s Controls Are Represented in This Manual To help navigate the scanner’s menus, the steps shown in this manual show the displays you see and the keys you press or control you operate to get a desired result. This example shows you how to use the scanner’s menu to edit an existing system name. It shows you the key to press ( Menu ) to select a menu option and the option you see (Program System) when you press Menu . It also instructs you to turn the scroll control (shown as ) to view a series of choices then select one choice (Edit Name). Menu E Program System Select the system Edit Name E E System Name To get the most from this manual, review the contents to become familiar with the basic functions available. If you are new to scanning or trunk tracking, be sure to Feature Highlights 16 read “Understanding Scanning” on Page 18 for a quick background on the technology. The first thing you’ll need to do is install batteries in the scanner. Then you need to connect the included antenna to the scanner. See “Setting Up Your Scanner” on Page 30 if you need any help doing this. Entering Text To enter a letter, turn the scroll control until the character you want appears, To enter a number, press a number key. To enter a decimal point, press . To move the cursor to the left, hold Func then press /4 or rotate the scroll control to the left. To move the cursor to the right, hold Func then press 6/ or rotate the scroll control to the right. To clear a character, press No twice. To clear all characters, press No 3 times. To accept an entry, press E or press down on the scroll control. Feature Highlights 17 Understanding Scanning This section provides you with background on how Understanding Scanning scanning works. You don’t really need to know all of this to use your scanner, but some background knowledge will help you get the most from your BC246T. Understanding the Scanner’s Memory Your scanner’s memory is organized in an architecture called Dynamic Allocated Channel memory. This type of memory is organized differently and more efficiently than the bank/channel architecture used by traditional scanners. Dynamic Allocated design matches how radio systems actually work much more closely, making it easier to program and use your scanner and determine how much memory you have used and how much you have left. Instead of being organized into separate banks and channels, your scanner’s memory is contained in a pool. You simply use as much memory as you need in the pool to store as many frequencies, talk group ID’s, and alpha tags as you need. No memory space is wasted, and you can tell at a glance how much memory you have used and how much remains. With a traditional scanner, when you program it to track a trunked system, you must first program the frequencies. Since you can only program one trunking system per bank in a traditional scanner, if there were (for example) 30 frequencies, the remaining 70 or so channels in the bank are not used and therefore wasted. Also, since some trunked systems might have hundreds of talk groups, you would have had to enter those types of systems into multiple banks in order to monitor and track all the ID’s. What is Scanning? Unlike standard AM or FM radio stations, most two-way communications do not transmit continuously. Your BC246T scans programmed channels until it finds an active frequency, then stops on that frequency and remains on that channel as long as the transmission continues. When the transmission ends, the scanning Understanding Scanning 18 cycle resumes until the scanner receives another transmission. What is Searching? The BC246T can search each of its 21 bands and up to 10 bands together to find active frequencies. This is different from scanning because you are searching for frequencies that have not been programmed into the scanner. When you select frequency bands to search, the scanner searches for any active frequency within the lower and upper limits you specify. When the scanner finds an active frequency, it stops on that frequency as long as the transmission lasts. If you think the frequency is interesting, you can program it into the scanner’s memory. If not, you can continue to search. What is CTCSS/DCS? Your scanner can monitor systems using a Continuous Tone Coded Squelch System (CTCSS) and Digital Coded Squelch (DCS) system, which allow squelch to open only when the tone you have programmed with a specific frequency is received along with a transmission. CTCSS and DCS are subaudible tone signaling systems sometimes referred to as PL or DPL (Motorola’s trademarked terms for Private Line and Digital Private Line respectively). CTCSS and DCS are used only for FM signals and are usually associated with both amateur and commercial two-way frequencies. These systems make use of a special subaudible tone that accompanies a transmitted signal. CTCSS and DCS are used for many purposes. In many cases, CTCSS and DCS are used to restrict access to a commercial repeater, so that only those units, which transmit the correct tone along with their signal can “talk” to the repeater. CTCSS and DCS are also used in areas that receive interference where there are several stations with output frequencies close to each other. When this occurs, you might hear multiple communications on the same Understanding Scanning 19 frequency. The stations might even interfere with each other to the point where it is impossible to clearly receive any of the stations. A scanner equipped with CTCSS and DCS (like your scanner) can code each received frequency with a specific CTCSS or DCS frequency. Then, when you receive multiple signals, you only hear the transmission with the CTCSS or DCS tone you programmed. If you do not receive the correct tone with a signal, the scanner’s squelch remains closed and you hear nothing. You can search for the following CTCSS frequencies and DCS codes. CTCSS Frequencies (Hz) 67.0 82.5 100.0 123.0 151.4 171.3 189.9 210.7 69.3 85.4 103.5 127.3 156.7 173.8 192.8 218.1 71.9 88.5 107.2 131.8 159.8 177.3 196.6 225.7 250.3 74.4 91.5 110.9 136.5 162.2 179.9 199.5 229.1 254.1 77.0 94.8 114.8 141.3 165.5 183.5 203.5 233.6 79.7 97.4 118.8 146.2 167.9 186.2 206.5 241.8 DCS Codes (Octal) 023 051 114 143 174 245 266 332 411 025 053 115 145 205 246 271 343 412 026 054 116 152 212 251 274 346 413 031 065 122 155 223 252 306 351 423 032 071 125 156 225 255 311 356 431 036 072 131 162 226 261 315 364 432 043 073 132 165 243 263 325 365 445 047 074 134 172 244 265 331 371 446 Understanding Scanning 20 452 506 612 703 454 516 624 712 455 523 627 723 462 526 631 731 464 532 632 732 465 546 654 734 466 565 662 743 503 606 664 754 Conventional Scanning Conventional scanning is a relatively simple concept. Each group of users in a conventional system is assigned a single frequency (for simplex systems) or two frequencies (for repeater systems). Any time one of them transmits, their transmission always goes out on the same frequency. Up until the late 1980s, this was the primary way that radio systems operated. Even today, there are many 2-way radio users who operate using a conventional system: • Aircraft • Amateur radio • FRS/GMRS users • Broadcast AM/FM/TV stations • Many business radio users When you want to store a conventional system, all you need to know is the frequencies they operate on. When you are scanning a conventional system, the scanner stops very briefly on each channel to see if there is activity. If there isn’t, the scanner quickly moves to the next channel. If there is, then the scanner pauses on the transmission until it is over. Simplex Operation Simplex systems use a single frequency for both transmit and receive. Most radios using this type of operation are limited to line-of-sight operation. This type of radio is frequently used at construction job sites, and with inexpensive consumer radios such as GMRS/FRS radios. The range is typically 1-8 miles, depending upon the terrain and many other factors. Understanding Scanning 21 Repeater Operation Repeater systems use two frequencies: one transmits from the radio to a central repeater; the other transmits from the repeater to other radios in the system. With a repeaterbased system, the repeater is located on top of a tall building or on a radio tower that provides great visibility to the area of operation. When a user transmits (on an input frequency), the signal is picked up by the repeater and retransmitted (on an ou