Uniden BC125AT Owner's manual

BC125AT Owners

Manual

Fort Worth, Texas U01UB370ZZC(0)

PRECAUTIONS

Before you use this scanner, please read and observe the

following.

EARPHONE WARNING!

Be sure to use only a monaural earphone with this scanner. You

can also use an optional stereo headset. Use of an incorrect

earphone or mono 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 headset.

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.

WARNING!

Uniden does not represent this unit to be waterproof. To reduce

the risk of re or electrical shock, do not expose this unit to rain

or moisture.

Uniden® is a registered trademark of Uniden America

Corporation.

Close Call™ is a trademark of Uniden America Corporation.

CONTENTS

PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

THE FCC WANTS YOU TO KNOW . . . . . . . . . . . . . . . . . . . . . . . . . 6

SCANNING LEGALLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FEATURE HIGHLIGHTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FREQUENCY RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

USA Band Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Canada Band Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

INCLUDED WITH YOUR SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

OPTIONAL ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

SCANNING BASICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

WHAT IS SCANNING? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

WHAT IS SEARCHING? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

UNDERSTANDING SCANNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

What is CTCSS/DCS? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Conventional Scanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Simplex Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Repeater Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

UNDERSTANDING BANKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Channel Storage Banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Service Search Banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Custom Search Banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

WHERE TO LEARN MORE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

SETTING UP YOUR SCANNER. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

CONNECTING THE ANTENNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Connecting an Optional Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

CONNECTING AN EARPHONE/HEADPHONE . . . . . . . . . . . . . . . . . . . . . . . . 21

CONNECTING AN EXTENSION SPEAKER . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

ADJUSTING THE BELT CLIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

POWERING THE SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Installing Non-Rechargeable Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Installing Rechargeable Ni-MH Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Charging the Ni-MH Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

ABOUT YOUR SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

GETTING TO KNOW THE SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

TURNING ON THE SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

A LOOK AT THE DISPLAY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

SETTING UP YOUR SCANNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Using the

SCROLL CONTROL Knob . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Adjusting the Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Adjusting the Squelch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Setting the Backlight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Adjusting the Contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Setting the Charging Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Using the Keypad Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Setting the Beep Tone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Resetting the Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

PC Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

PROGRAMMING CHANNELS . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

PROGRAMMING CHANNEL TEXT TAGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

SETTING CTCSS/DCS FOR A CHANNEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

SETTING CHANNEL MODULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

SETTING THE PRIORITY CHANNEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

SETTING CHANNEL DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

DELETING CHANNELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Clearing a Bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

SCANNING STORED CHANNELS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Priority Scan Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

MANUALLY SELECTING A CHANNEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Locking Out Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Unlocking Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Unlock all Channels in Banks Currently Enabled for Scan . . . . . . . . . . . 47

SERVICE SEARCH MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Service Search Receive/Hold Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Custom Search Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Custom Search Receive/Hold Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Quick Search Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Quick Search Receive/Hold Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Search Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Programming Custom Search Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Storing Found Search Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Locking Out Search Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Unlocking Search Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

CLOSE CALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Using the Close Call Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Selecting Close Call Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Close Call Only Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Set Close Call Bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Close Call Alert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Close Call Hits Bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Close Call Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Close Call CTCSS/DCS Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

WEATHER OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

SEARCHING FOR A WEATHER BROADCAST . . . . . . . . . . . . . . . . . . . . . . . . . 63

WEATHER ALERT STANDBY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

WEATHER ALERT PRIORITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

TECHNICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 65

RBRC INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

CTCSS FREQUENCIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

DSC CODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

BIRDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

ONE YEAR LIMITED WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

THE FCC WANTS YOU TO KNOW

This scanner has been tested and found to comply with

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 o, 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.

7

SCANNING LEGALLY

Your scanner covers frequencies used by many dierent

groups, including police and re departments, ambulance

services, government agencies, private companies, amateur

radio services, military operations, pager services, and wire-line

(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

According to the Electronic Communications Privacy Act

(ECPA), you are subject to nes 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 modications 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.

8

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 ocials by traveling to the scene of an incident

without authorization.

Changes or modications 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.

INTRODUCTION

Thank you for purchasing a Uniden BC125AT Handheld Scanner.

The scanner is versatile, compact, and easy to use. In addition

to its standard scanning features, your scanner also includes

Close Call™ RF capture technology designed to help you detect

and identify strong local radio signals in your area. You can

program up to 500 frequencies into the scanner's memory either

manually or using optional computer software. The scanner

lets you scan transmissions and is preprogrammed with service

banks for your convenience. You can quickly search those

frequencies most commonly used by police and other agencies,

without tedious and complicated programming. The scanner

gives you direct access to over 40,000 exciting frequencies. Use

your scanner to monitor:

• Police

• Fire/Emergency

• HAM Radio

• Marine

9

• Railroad

• Civil Air

• Military Air

• CB Radio

• FRS/GMRS/MURS

• Racing

FEATURE HIGHLIGHTS

10 Channel Storage Banks - You can store up to 50 frequencies

into each bank for a total of 500 frequencies so you can more

easily identify calls.

Close Call™ RF Capture Technology - you can set the scanner

so it detects and provides information about nearby radio

transmissions

Close Call Do-Not-Disturb - checks for Close Call activity

in between channel reception so active channels are not

interrupted.

Close Call Temporary Store - temporarily stores and scans the

last 10 Close Call hits in the Close Call Hits bank.

PC Programming - you can download information into the

scanner and upload to the scanner via your personal computer.

CTCSS and DCS Squelch Modes - rapid search for CTCSS/DCS

tones/codes used during a transmission. You can identify up to

50 CTCSS tones and 104 DCS codes.

Direct Access - lets you directly access any channel.

Lock-Out Function - lets you set your scanner to skip over

specied channels or frequencies when scanning or searching.

10

Temporary Lockout - makes it easy to temporarily lock out

any channel or frequency. The lockout is cleared when you

turn power o, then back on so you don’t have to remember to

unlock the channels or frequencies later.

Triple-Conversion Circuitry - virtually eliminates any

interference from IF (intermediate frequency) images, so you

hear only the selected frequency.

Text Tagging - you can name each channel, using up to 16

characters per name.

Service Banks - frequencies are preset in 10 separate Police,

Fire/Emergency, Ham, Marine, Railroad, Civil Air, Military Air, CB

Radio, FRS/GMRS/MURS, and Racing banks to make it easy to

locate specic types of calls and search any or all of these banks.

Priority Scan with Do Not Disturb - lets you program one

channel in each bank (10 in all) and then have the scanner check

each channel every 2 seconds while it scans the banks so you

don’t miss transmissions on those channels. Do-Not Disturb

keeps the scanner from interrupting transmissions during

receiving.

Priority Plus Scan - you can set the scanner so it scans only the

priority channels.

Scan/Search Delay/Resume - controls whether the scanner

pauses at the end of the transmission to wait for a reply. You can

set the Delay time for each Channel, Close Call Search, Custom

Search, and Service search. You can also set a negative delay

where the scanner stops on transmissions for a set time then

automatically resumes.

11

Custom Search - lets you program up to 10 Custom Search

Ranges and search any or all of these ranges.

Quick Search - allows you to enter a frequency and start

searching up or down from that frequency.

Turbo Search - increases the search speed from 100 to 300

steps per second automatically for bands with 5 kHz steps.

Search Lockouts - you can lock up to 200 search frequencies:

100 temporary frequencies and 100 permanent frequencies

in Custom Search, Service Search, Close Call Search, or Quick

Search Modes.

Weather Alert Priority - the scanner scans active WX channels

every 5 seconds to check for the presence of a 1050 Hz Weather

Alert Tone.

Weather Alert Standby - the scanner allows you to monitor for

weather alerts broadcast on NOAA channels.

Display Backlight - You can turn on/o the LCD backlight, set it

operate on squelch only, keypress only, or both.

Signal Strength Meter - shows the signal strength for more

powerful transmissions.

Flexible Antenna with BNC Connector - provides adequate

reception in strong signal areas and is designed to help prevent

antenna breakage. You can also connect an external antenna for

better reception.

Memory Backup - keeps the frequencies stored in memory for

an extended time if the scanner loses power.

12

Three Power Options - let you power the scanner using the

included two AA rechargeable or alkaline batteries or the

supplied USB cable.

Built-In Charger - allows you to charge Ni-MH batteries in the

scanner using a USB port on any computer and the supplied

USB cable.

Key Conrmation Tones - You can turn on/o a tone that

sounds when you perform an operation correctly or if you make

an error.

Key Lock - lets you lock the scanner's keys to help prevent

accidental changes to the scanner's programming.

Battery Save - works when there is no transmission for 1 minute

in Scan Hold mode and any Search Hold mode (without

Priority Scan). This feature turns o RF power for 1 second and

turns on it for 300ms to extend the battery life.

Battery Low Alert - the

BATT

icon will blink in the display and a

tone warns you every 15 seconds when the battery power gets

low.

FREQUENCY RANGE

This table lists the frequency ranges, frequency steps, default

modulation, and type of transmissions you can hear for each

range.

13

USA Band Plan

FREQUENCY (MHz)

STEP

(kHz)

MODE BAND

LOWER UPPER

25.0000 27.9950 5.0 AM

Petroleum Products & Broadcast

Pickup

CB Class D Channel

Business & Forest Products

28.0000 54.0000 5.0 NFM

10 Meter Amateur Band

VHF Low Band

6 Meter Amateur Band

108.0000 136.9916 8.33 AM Aircraft Band

137.0000 150.7700 5.0

NFM

Military Land Mobile

2 Meter Amateur Band

Military Land Mobile

VHF High Band

Federal Government

150.7750 150.8125 7.5

150.8150 154.4525 7.5

154.4562 154.4787 7.5

154.4825 154.5125 7.5

154.5150 154.5250 5.0

154.5275 154.5350 7.5

154.5400 154.6075 7.5

154.6100 154.6475 7.5

154.6500 157.4475 7.5

157.4500 157.4650 5.0

157.4700 163.2450 7.5

163.2500 173.2000 12.5

173.2037 173.2100 6.25

173.2150 173.2200 5.0

173.2250 173.3875 12.5

173.3900 173.3962 6.25

173.4000 174.0000 5.0

225.0000 380.0000 12.5 AM Military Air Band

14

FREQUENCY (MHz)

STEP

(kHz)

MODE BAND

LOWER UPPER

400.0000 512.0000 6.25 NFM

Miscellaneous

Federal Government Land

Mobile

70 cm Amateur Band

UHF Standard Band

Canada Band Plan

FREQUENCY (MHz)

STEP

(kHz)

MODE BAND

LOWER UPPER

25.0000 27.9950 5.0 AM

Petroleum Products & Broadcast

Pickup

CB Class D Channel

Business & Forest Products

28.0000 54.0000 5.0 NFM

10 Meter Amateur Band

VHF Low Band

6 Meter Amateur Band

108.0000 136.9916 8.33 AM Aircraft Band

137.0000 174.0000 5.0 NFM

Military Land Mobile

2 Meter Amateur Band

Military Land Mobile

VHF High Band

Federal Government

225.0000 380.0000 12.5 AM Military Air Band

400.0000 512.0000 6.25 NFM

Miscellaneous

Federal Government Land

Mobile

70 cm Amateur Band

UHF Standard Band

INCLUDED WITH YOUR SCANNER

• BC125AT scanner with attached belt clip

• Antenna

• Rechargeable Ni-MH Batteries

• USB cable

15

• Wrist strap

If any of these items are missing or damaged, immediately

contact your place of purchase or Uniden Customer Service

at: (800) 297-1023, 8:00 AM to 5:00 PM, CST, Monday through

Friday.

OPTIONAL ACCESSORIES

Contact your local Uniden Dealer or call the Uniden Parts

Center at: (800)554-3988, 8:00AM to 5:00PM EST, Monday

through Friday, for information about ordering these optional

accessories.

Note: USB cables are also available from the Uniden On-Line store.

Visit http://www.uniden.com.

SCANNING BASICS

This section provides you with background on how 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 BC125AT.

WHAT IS SCANNING?

Unlike standard AM or FM radio stations, most two-way

communications do not transmit continuously. Your BC125AT

scans programmed channels until it nds 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 cycle resumes until the scanner receives another

transmission.

16

WHAT IS SEARCHING?

The BC125AT can search for active frequencies. This is dierent

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 nds an active frequency, it stops on that frequency

as long as the transmission lasts. If you think the frequency is

interesting, you can store it into one of the banks. If not, you can

continue to search.

UNDERSTANDING SCANNING

What is CTCSS/DCS?

Your scanner can monitor systems using a Continuous Tone

Coded Squelch System (CTCSS) and Digital Coded Squelch (DCS)

system, which allows the squelch to open only when the tone

you have programmed with a specic frequency is received

along with a transmission.

CTCSS and DCS are sub-audible 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 sub-audible

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.

17

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 frequency. The stations

might even interfere with each other to the point where it is

impossible to clearly receive any of the stations. Your scanner

can code each received frequency with a specic sub-audible

CTCSS or DCS frequency or code. 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.

Refer to the Reference section of this manual for tables showing

the available CTCSS frequencies and DCS codes.

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 1980’s

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

• Many business radio users

18

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 briey

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.

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 repeater-based 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 output

frequency). The user’s radios always listen for activity on the

output frequency and transmit on the input frequency. Since

the repeater is located very high, there is a very large line of

sight. Typical repeater systems provide coverage out to about a

25-mile radius from the repeater location.

19

UNDERSTANDING BANKS

Channel Storage Banks

To make it easier to identify and select the channels you want to

listen to, the 500 channels are divided into 10 channel storage

banks containing 50 channels each. You could use each channel

storage bank to group frequencies by department, location,

area of interest, or any other way you prefer. You can listen to

any or all of the banks by using the number keys to turn them

on or o.

Service Search Banks

The scanner is preprogrammed with many of the frequencies

allocated to Police, Fire/Emergency, Ham, Marine, Railroad, Civil

Air, Military Air, CB radio, FRS/GMRS/MURS, and Racing services.

There are 10 banks allocated for these searches that can be used

just like the channel storage banks to search these frequencies

in Service Search mode.

Custom Search Banks

Custom Search Banks let you program and search 10 custom

search ranges. During custom search, the scanner starts

searching with the lowest frequency in the search range you

select to the highest frequency in the range. You can search any

or all of these ranges by turning each search bank on or o just

like channel storage banks in Search mode.

WHERE TO LEARN MORE

By itself, this manual really only provides part of what you

need to know to have fun scanning – how to program and

use the scanner. The website, http://www.radioreference.

com, is the Internet's premier source for user-supported radio

20

system information. This web sites is not aliated with Uniden

Corporation.

For more information about Uniden and our other products,

visit http://www.uniden.com.

SETTING UP YOUR SCANNER

These guidelines will help you install and use your new scanner.

If your scanner receives interference or electrical noise, move

the scanner or its antenna away from the source. You might also

try changing the height or angle of the rubber antenna.

To improve the scanner’s reception, use an optional external

antenna designed for multiband coverage. (You can purchase

this type of antenna at a local electronics store). If the optional

antenna has no cable, use 50 ohm coaxial cable for lead-in. An

adapter plug might be necessary for the optional antennas.

Use an optional mono earphone or stereo headset with proper

impedance for private listening. Read the precautions on the

inside front cover of this Owners Manual.

Do not use the scanner in high-moisture environments such as

the kitchen or bathroom.

Avoid placing the scanner in direct sunlight or near heating

elements or vents.

CONNECTING THE ANTENNA

1. Align the slots around the antenna's connector with the

tabs on the scanner's BNC connector.

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Uniden BC125AT Owner's manual

Uniden BC125AT Owner's manual

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