Scanner Frequently Asked Questions
Section 1 - Scanner Basics



What is a scanner and why would I want / need one?

A scanner is a radio receiver designed to allow you to listen to radio transmissions from the various agencies and companies using radio communications in your area, such as police and fire departments, ambulance services, government agencies, air, and amateur radio services. Scanners let you scan these transmissions and are often preprogrammed with service search banks for convenience. By pressing a single button, you can quickly search those frequencies most commonly used by public service and other agencies without tedious and complicated programming. Scanning is a growing hobby that lets you "listen in" on public radio conversations and keep up on current local events as they are happening.

 

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What different types of scanners are available?

Scanners are broken down by physical types and scanning methods.

The three physical types of scanners are Handheld, Mobile and Desktop. The primary differences between them are shown in the table below. Range is dependent on the antenna used, and a handheld scanner can usually be used in a mobile or desktop environment by attaching it to a vehicle-mounted or base-station antenna (see Scanner Antennas and Other Accessories).

Scanner Type Primary Usage Power Source Antenna Advantages Disadvantages
Handheld Scanners for Personal use Battery, AC/DC Jack Small Rubber Antenna Portability, Small size Shortest Range
Mobile Scanners for use in Vehicles DC Power Connections Vehicle-mounted Antenna Optimized for Vehicle Use Vehicle Only
Desktop Scanners for use at Home AC Power Connections Base-station Antenna Optimized for Desktop Use AC Power Only

The three basic scanning methods are Crystal-controlled, Conventional Programmable and Trunk Tracking Programmable.

Early scanners were crystal-controlled. These scanners had one or more internal slots for a crystal which allowed the radio to receive a single frequency. Crystal-controlled scanners are not currently being sold. However, a number of them turn up in pawn shops and garage sales. For example, the PRO-25 (Cat. No. 200-0106), PRO-27 (Cat. No. 200-0108), and PRO-53 (Cat. No. 200-0122) scanners were of this type. Generally, if you are looking at a RadioShack scanner and it does not have a keypad or program button, it is probably crystal-controlled. The disadvantage of crystal-controlled scanners is that they were slow to tune, expensive to set-up for new frequency/channel activity, and they can not follow the new trunked radio activity.

In the mid-80's, programmable scanners were introduced. These use integrated circuits to allow the radio to tune to a range of frequencies and were a marked improvement over crystal-controlled scanners, which required the purchase and installation of different crystals. Programmable scanners come with a wide range of features and capabilities and are distinguished from one another by the following features:

 

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Conventional Programmable Scanners:

RadioShack Scanners Features

PRO-79 Handheld Scanner
(Cat. No. 20-314)

Click For More Info On The PRO-79!

Memory Channels: 200

Computer Interface: Scanner PC Programming Kit (Cat. No. 20-048)

Conversion System: Dual Conversion

Size: 5 11/16" x 2 3/8" x 1 3/8"

Weather Alert: Yes

Frequency Range:
29-54 MHz, 108-174 MHz, 380-512 MHz

User's Manual Available On-line

 

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PRO-89 Handheld Racing Scanner
(Cat. No. 20-514)

Click For More Info On The PRO-89!

Memory Channels: 200

Computer Interface: Scanner PC Programming Kit (Cat. No. 20-048)
or Over-the-Air Programming

Conversion System: Triple Conversion

Size: 5 7/8" x 2 1/2" x 1 3/8"

Weather Alert: Yes

Race Car Number On Display

Frequency Range:
29-54 MHz, 108-174 MHz, 380-512, 806-960 MHz (less cellular)

User's Manual Available On-line
Tutorials Available On-line

 

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PRO-2018 Desktop Scanner
(Cat. No. 20-424)

Click For More Info On The PRO-2018!

Memory Channels: 200

Computer Interface: Scanner PC Programming Kit (Cat. No. 20-048)

Conversion System: Dual Conversion

Size: 2 1/8" x 8 1/2" x 7"

Weather Alert: Yes

Frequency Range:
29-54 MHz, 108-136.9875 MHz, 137-174 MHz, 380-512 MHz

 

User's Manual Available On-line

 

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Trunking Programmable Scanners:

The newest innovation in scanners is Trunking Scanners. Trunking scanners are designed to track Motorola Type I and Type II (such as Smartnet™ and Privacy Plus™) and hybrid analog trunking systems, plus GE/Ericsson (EDACS) and EF Johnson (LTR) type systems, which are extensively used in many communication systems. Trunking communications 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 simply selects a talk group. The trunking system automatically transmits the call on the first available frequency, and also sends a code that uniquely identifies that transmission. Since the trunking system might send a call and its response on different frequencies, it is difficult to listen to trunked communications using a regular scanner. Trunking scanners monitor the data sent with a 2-way radio transmission so you can hear the call and response for that user and more easily "follow" the conversation.

PRO-94 Handheld Trunking Scanner
(Cat. No. 20-524)

Click For More Info On The Pro-94!

Memory Channels: 1000

Computer Interface: No

Conversion System: Triple Conversion

Size: 6 5/16" x 2 5/8" x 1 3/4"

Weather Alert: Yes

Frequency Range:
29-54, 108-174, 216-225, 406-512, 806-960 (excluding cellular) and 1240-1300 MHz

User's Manual Available On-line

 

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PRO-95 Handheld Trunking Scanner
(Cat. No. 20-525)

Click For More Info On The Pro-93!

Memory Channels: 1000

Computer Interface: PC interface, and can clone another PRO-95

Conversion System: Triple Conversion

Weather Alert: Yes

Frequency Range:
25-54, 108-136.9875, 137-174, 216-225, 406-512, 806-960 (excluding cellular) and 1240-1300 MHz

User's Manual Available On-line

 

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PRO-2067 Mobile Trunking Scanner
(Cat. No. 20-196)

Click For More Info On The PRO-2067!

Memory Channels: 500

Computer Interface: Can clone from a PRO-92 Handheld with included cable or by using the Software and Cable (Available as Cat. No. 940-1223 or RSU 12204327). RSU items can be ordered through your local RadioShack Store or by calling the RadioShack Order Center at 800-843-7422.

Conversion System: Triple Conversion

Size: 2" x 6 7/8" x 6 3/8"

Weather Alert: Yes

Frequency Range:
29-54, 108-174, 380-512, 806-960 MHz (excluding cellular)

User's Manual Available On-line

 

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PRO-2053 Desktop Trunking Scanner
(Cat. No. 20-466)

Click For More Info On The PRO-2053!

Memory Channels: 300

Computer Interface: Scanner PC Programming Kit (Cat. No. 20-048)

Conversion System: Triple Conversion

Size: 3 3/8" x 8 7/16" x 6 9/16"

Weather Alert: Yes

Frequency Range:
29-54, 108-174, 216-225, 406-512, 806-960 (excluding cellular) and 1240-1300 MHz

User's Manual Available On-line

 

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PRO-2052 Desktop Trunking Scanner
(Cat. No. 20-432)

Click For More Info On The PRO-2052!

Memory Channels: 1000

Computer Interface: with Cable (Cat. No. 26-117) and the Software (Available as Cat. No. 940-1222 or RSU 12236857). RSU items can be ordered through your local RadioShack Store or by calling the RadioShack Order Center at 800-843-7422.

Conversion System: Triple Conversion

Size: 2 3/4" x 8 1/16" x 7 11/16"

Weather Alert: Yes

Frequency Range:
29-54, 108-174, 179.75-512, 806-956 (excluding cellular) and 1240-1300 MHz

User's Manual Available On-line

 

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What can I legally listen to?

You can hear police and fire departments, ambulance services, government agencies, private companies, amateur radio services, aircraft, and military operations. It is legal to listen to almost every transmission your scanner can receive. However, there are some electronic and wire communications that are illegal to intentionally intercept. These include: telephone conversations (cellular, cordless, or other private means of telephone signal transmission), pager transmissions, and scrambled or encrypted transmissions. According to the Federal Electronic Communications Privacy Act (ECPA), as amended, you could be fined and possibly imprisoned for intentionally listening to, using, or disclosing the contents of such a transmission unless you have the consent of a party to the communication (unless such activity is otherwise illegal). These laws change from time to time and there might be state or local laws that also affect legal scanner usage.

 

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What accessories are available to improve my scanning?

We offer several accessories for our scanners, such as noise-blocking headphones, antenna mounts and antennas.

 

Headphones

Noise-Reducing Race Scanner Headphones
(Cat. No. 33-1158)

These RadioShack Noise-Blocking Race Scanner Headphones are ideal for use in noisy locations like race tracks. They effectively block out external noise —- up to 20 dB. Perfect for use with the RadioShack Race Scanner. Easily adjustable volume control is conveniently located on the left ear cup. The heavy-duty cord is tightly coiled so it stays out of your way. Soft fluid-filled ear cushions and adjustable hook-and-loop headband provide a comfortable fit for hours of listening comfort. Specifically designed for voice transmissions —- wide 40-20,000Hz frequency response provides crisp, clear sound.

Product Features:

  • For use with all mono sources
  • 1/8” gold-plated mono plug
  • Neodymium magnets
  • 8-foot cord

 

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Click For More Info On The Race Scanner Headphones!

 

Antenna Mounts

Clip-On Antenna Mount
(Cat. No. 20-023)

Product Features:

  • Window clip mounts antenna on glass
  • Works with scanner or handy-talkie flex antennas
  • For car, home, and travel
  • 6 foot cord with BNC plug

 

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Click For More Info !

 

Antennas for Base Stations

Outdoor Scanner/Ham Discone Antenna
(Cat. No. 20-043)

Product Features:

  • Omnidirectional, rugged stainless steel construction
  • Wide 25 - 1300 MHz receive coverage
  • Transmits on 50, 144, 220, 440, 900 and 1296 MHz Ham bands
  • Resonator and tunable whip for best 50 MHz performance
  • About 44" high, overall
  • Fits mast up to 1" in diameter
  • Accepts PL-259 connector
    (Use plug adapter 278-117 for scanners that have BNC connector)

 

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Click For More Info!

Outdoor VHF-Hi/UHF Scanner Antenna
(Cat. No. 20-176)

Product Features:

  • Chrome-plated brass vertical element
  • Covers 108 to 1300 MHz with peak performance in 152-470 MHz
  • About 20" high
  • Accepts PL-259 connector
    (Use plug adapter 278-117 for scanners that have BNC connector)

 

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Click For More Info!

Indoor Scanner Antenna
(Cat. No. 20-161)

Product Features:

  • Covers 30 to 512MHz
  • Extends to 40"
  • Accepts PL-259 connector
    (Use plug adapter 278-117 for scanners that have BNC connector)

 

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Click For More Info!

 

Antennas for Mobile Stations

Magnet-Mount Mobile Scanner Antenna
(Cat. No. 20-032)

Product Features:

  • Covers 25 to 1300 MHz
  • About 36" high
  • Includes 16 foot cable with BNC type adapter connector

Note: Magnetic-mount antennas are not recommended for use on vinyl roofs.

 

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Click For More Info!
Mobile "Cellular Look-Alike" Glass-Mount Scanner Antenna
(Cat. No.20-011)

Product Features:

No holes to drill. Easily installs on windshield or window.

  • Covers 25 to 1300 MHz
  • 22"-high element
  • Includes 16-foot cable with BNC connector.

 

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Click for More Info!

 

Antennas for Handheld Stations

Deluxe Antenna for Handheld Scanner
(Cat. No. 20-034)

Product Features:

  • Longer 9" length helps improve reception of marginal signals
  • BNC connector fits all RadioShack and most other handheld scanners
  • Can also be used with Ham HT's for transmitting on the 144 MHz or 440 MHz Ham bands.

 

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Click For More Info!

Center-Loaded Telescoping Whip Antenna
(Cat. No. 20-006)

Product Features:

  • Receives 25 to 1300MHz
  • Transmits on 144 MHz, 220 MHz and 440MHz Ham bands
  • Nine sections

 

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Click For More Info!

A broadcaster in my area now uses a digital system; why can't I find a digital scanner?

Currently, most radio systems are analog systems; however, some areas have begun using digital radio systems. At this time, all of our scanners are analog only; we do not currently sell a digital scanner.

 

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What are birdies?

Birdies are frequencies your scanner uses when it operates. These operating frequencies might interfere with broadcasts on the same frequencies. If you program one of these frequencies, you will hear only noise on that frequency. If the interference is not severe, you might be able to turn up the squelch to cut out the birdie. The most common birdies to watch for are listed below.

Birdie Frequencies

31.05 MHz 124.20 MHz
41.40 MHz 134.55 MHz
51.75 MHz 144.90 MHz
113.85 MHz 155.25 MHz

You can use the following procedure to check for birdies in your particular scanner.

  1. Remove the antenna.
  2. Turn the scanner on and set up a limit search for all bands on the scanner.
  3. Be sure that the scanner is separated from possible signal sources such as a PC, other transceivers, etc.
  4. Write down the frequencies where the scan stops or detects a continuous noise signal. These are the Birdies.
 

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Reception Notes

Reception of the frequencies covered by your scanner is mainly "line of sight". That means you usually cannot hear stations that are beyond the horizon. During the summer months you may be able to hear stations in the 30-50 MHz range located several hundred or even thousands of miles away. This is because of summer atmospheric conditions. This type of reception is unpredictable but often very interesting! One very useful service is the National Weather Service's continuous weather broadcast. These broadcasts contain weather forecasts and data for the areas around the station, plus bulletins on any threatening weather conditions. These stations use several frequencies; and in most areas of the country, you can receive one of these frequencies.

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General Troubleshooting

Check that you are following the correct steps per the manual.

Check the frequency to be sure you are entering it correctly.

Check the scanner's frequency coverage to be sure that the scanner can receive that frequency.

Check the scanner's reception ability by programming a known continuous voice broadcast such as NOAA on 162.4Mhz – 162.55Mhz.

You can do this by going to the Weather service band (if available on your scanner) or by programming a limit search from 160Mhz – 170Mhz.

Reset the scanner as a last resort; this erases all memory contents and resets the radio back to factory settings. The reset for most RadioShack scanners is given below; however, for some models there is no reset and the only way to reset the scanner is to remove power.

  1. Turn the scanner off.
  2. Push the 2 and 9 buttons and hold them down.
  3. Turn the scanner on while holding down the buttons.
  4. Release the 2 and 9 after the display shows CLEAR.
 

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A Guide To The Action Bands

With the right frequencies programmed into your scanner, you can monitor exciting events. With a little investigation, you can find active frequencies in your community. We can give you some general pointers, and you can take it from there. Please use caution and common sense when you hear an emergency call. Never go to the scene of an emergency. It could be very dangerous. Find out if there is a local club that monitors your community's frequencies. Perhaps a local electronics repair shop that works on equipment similar to your scanner can give you frequencies used by local radio services. A volunteer police department or fire department can also be a good source for this information.

As a general rule on VHF, most activity is concentrated between 153.785 and 155.98 MHz and then again from 158.73 to 159.46 MHz. Here you find local government, police, fire and most such emergency services. If you are near a railroad yard or major railroad tracks, look around 160.0 to 161.9 MHz for signals.

In some larger cities, there has been a move to the UHF bands for emergency service. Here, most of the activity is between 453.025 and 453.95 MHz and between 456.025 and 467.925 MHz.

In the UHF band, frequencies between 456.025 and 459.95 MHz and between 465.025 and 469.975 MHz are used by mobile units and control stations associated with base and repeater units that operate 5 MHz lower (that is, 451.025 to 454.950 and 460.025 to 464.975 MHz). This means that if you find an active frequency inside one of these spreads, you can look 5 MHz lower (or higher) to find the base station/repeater for that service.

 

Typical Band Usage

The following is a brief listing of the typical services that use bands that a scanner can receive. This listing helps you decide which ranges you would like to scan. These frequencies are subject to change, and might vary from area to area. For a more complete listing refer to the Police Call Radio Guide available at your local RadioShack store.

 

Abbreviations

MARS
Military Affiliate Radio System
Ham
Amateur Radio
Auto Emer.
Automobile Emergency
BC.R
Broadcast Remote
Bur.Recl.
Bureau of Reclamation
CAP
Civil Air Patrol
Agr. And For.
Department of Agriculture & Forestry.
F.D.
Fire Department
For.Prod.
Forest Products
Fors.Cons.
Forestry Conservation
Govt.
Government
Hwy.
Highway
Maintenance
Land Tr.
Land Transportation
L.Govt.
Local Government
Mfg.
Manufacturers
MIL
Military
Mob.Tel.
Mobile Telephone
Mot.P.
Motion Picture
Buses.Trucks
Motor Carrier
Nat.Park
National Parks
Pet.
Petroleum
P.D.
Police
Power
Power Utilities
Page
Radio Paging
R.R.
Railroad
Press
Relay Press
St.P.D.
State Police
Sp.Emer.
Special Emergency
Sp.Ind.
Special Industry
Taxi
Taxicab Radio
Tel.Maint.
Telephone Maintenance
U.S.C.G.S.
U.S. Coastal & Geodetic Survey
USN
U.S. Navy
U.S.W.B.
U.S. Weather Bureau
   

 

Attention: Your scanner may not be able to receive all frequencies and/or modes of reception that are contained within this document. For complete information of your scanner's capabilities, be sure to read your owner's manual completely.

 

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A Guide To Frequencies

 

National Weather Frequencies

161.650 MHz 161.775 MHz 162.400 MHz 162.425 MHz
162.440 MHz 162.450 MHz 162.475 MHz 162.500 MHz
162.525 MHz 162.550 MHz 163.275 MHz  

 

Ham Radio Frequencies

Ham operators often transmit emergency information when other communication methods break down. The following chart shows some of the frequencies that Hams use.

Wavelength (Meters) Frequency
10-meter 28.000-29.700 MHz
6-meter 50.000-54.000 MHz
2-meter 144.000-148.000 MHz
70-cm 420.000-450.000 MHz

 

Citizens Band

1) 26.965 MHz 9) 27.065 MHz 17) 27.165 MHz 25) 27.245 MHz 33) 27.335 MHz
2) 26.975 MHz 10) 27.075 MHz 18) 27.175 MHz 26) 27.265 MHz 34) 27.345 MHz
3) 26.985 MHz 11) 27.085 MHz 19) 27.185 MHz 27) 27.275 MHz 35) 27.355 MHz
4) 27.005 MHz 12) 27.105 MHz 20) 27.205 MHz 28) 27.285 MHz 36) 27.365 MHz
5) 27.015 MHz 13) 27.115 MHz 21) 27.215 MHz 29) 27.295 MHz 37) 27.375 MHz
6) 27.025 MHz 14) 27.125 MHz 22) 27.225 MHz 30) 27.305 MHz 38) 27.385 MHz
7) 27.035 MHz 15) 27.135 MHz 23) 27.255 MHz 31) 27.315 MHz 39) 27.395 MHz
8) 27.055 MHz 16) 27.155 MHz 24) 27.235 MHz 32) 27.325 MHz 40) 27.405 MHz

 

United States Broadcast Bands

In the United States, there are several broadcast bands. The standard AM and FM bands are probably the most well known. There are also four television audio broadcast bands -- the lower three transmit on the VHF band and the fourth transmits on the UHF band.

Frequency Range Allocation

VHF Television 54.0 - 72.0 MHz
VHF Television 76.0 - 88.0 MHz
Standard FM 88.0 - 108.0 MHz
VHF Television 174.0 - 216.0 MHz
UHF Television 470.0 - 805.75 MHz

 

International Broadcast Bands

Several short-wave bands are allocated for international broadcasting because of the nature of propagation of high frequencies. The bands are sometimes identified according to the approximate wavelength of the signals in meters. Your scanner may receive the 11-meter band, from 25.6 - 26.10 MHz.

 

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Typical and Primary Band Usage, and Specified Intervals

 

Typical Band Usage

HF Band (3.0 - 30.0 MHz)
25.00 - 28.63 MHz Mid Range
25.00 - 28.63 MHz Mid Range
28.00 - 29.70 MHz 10-Meter Amateur Band
29.70 - 29.90 MHz High Range
VHF Band (30.00 - 300.0 MHz)
30.00 - 50.00 MHz Low range
50.00 - 54.00 MHz 6-Meter Amateur
54.00 - 72.00 MHz FM-TV Audio Broadcast, Wide Band
88.00 - 108.00 MHz FM Radio Broadcast, Wide Band
108.00 - 136.00 MHz Aircraft
138.00 - 144.00 MHz U.S. Government
144.00 - 148.00 MHz 2-Meter Amateur
148.00 - 174.00 MHz High Range
220.00 - 222.00 MHz New Mobile Narrow Band
222.00 - 225.00 MHz 1.3-Meter Amateur
225.00 - 287.80 MHz Military Aircraft
UHF Band (300.00 MHz - 3.0 GHz)
311.00 - 384.00 MHz Military Aircraft
406.00 - 470.00 MHz U.S. Government
420.00 - 450.00 MHz 0.6-Meter Amateur
450.00 - 470.00 MHz Low Range
470.00 - 806.00 MHz FM-TV Audio Broadcast, Wide Band
851.00 - 856.00 MHz Conventional Systems
856.00 - 861.00 MHz Conventional/Trunked Systems
861.00 - 866.00 MHz Trunked Systems
866.00 - 869.00 MHz Public Safety
869.00 - 894.00 MHz Common Carrier
935.00 - 940.00 MHz Private Trunked
940.00 - 941.00 MHz General Trunked

 

Primary Usage

As a general rule, most of the radio activity is concentrated on the following frequencies:

VHF Band (30.00 - 300.0 MHz)
144.00 - 148.00 MHz 2-Meter Amateur
153.785 - 155.980 MHz Government, Police, and Fire
158.730 - 159.460 MHz Emergency Services
160.000 - 161.900 MHz Railroad
UHF Band (300.00 MHz - 3.0 GHz)
440.00 - 450.00 MHz 0.6-Meter Amateur Band FM Repeaters
450.000 - 470.000 MHz Land Mobile "Paired" Frequencies
451.025 - 454.950 MHz Base Stations
456.025 - 459.950 MHz Mobile Units
460.025 - 464.975 MHz Repeater Units
465.025 - 469.975 MHz Control Stations

Note: UHF remote control stations and mobile units typically operate at 5 MHz higher than their associated base and relay repeater units.

 

Specified Intervals

Frequencies in different bands are accessible only at specific intervals. For example:

VHF, HAM, and Government 5.0 kHz steps
All Others 12.5 kHz steps
Aircraft 25.0 kHz steps

Note: Your scanner rounds the entered frequency to the nearest valid frequency. For example, if you try to enter 151.473, the scanner might accept this as 151.470.

 

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Band Allocation

To help you decide which frequency ranges to search, use the following listing of the typical services that use the frequencies your scanner receives. These frequencies are subject to change, and might vary from area to area. For a more complete listing, refer to the "Police-Call Radio Guide including Fire and Emergency Services", as well as "Beyond Police Call", "Aeronautical Directory", "Nautical Directory" and "Now you're Talking" texts available at your local RadioShack store.

 

Abbreviations

AIR
Aircraft
BIFC
Boise (ID) Interagency Fire Cache
BUS
Business
CAP
Civil Air Patrol
CB
Citizens Band
CCA
Common Carrier
CSB
Conventional Systems
CTSB
Conventional/Trunked Systems
FIRE
Fire Department
HAM
Amateur (HAM) Radio
GOVT
Federal Government
GMR
General Mobile Radio
GTR
General Trunked
IND
Industrial Services
MARI
Maritime Limited Coast
MARS
Military Affiliate Radio System
MED
Emergency/Medical Services
MIL
U.S. Military
MOV
Motion Picture/Video Industry
NEW
Mobile Narrow
NEWS
Relay Press
OIL
Oil/Petroleum Industry
POL
Police Department
PUB
Public Services
PSB
Public Safety
PTR
Private Trunked
ROAD
Road & Highway Maintenance
RTV
Radio/TV Remote Broadcast Pickup
TAXI
Taxi Services
TELB
Mobile Telephone
TELC
Cordless Telephones
TELM
Telephone Maintenance
TOW
Tow Trucks
TRAN
Transportation Services
TSB
Trunked Systems
TVn
FM-TV Audio Broadcast
USXX
Government Classified
UTIL
Power & Water Utilities
WTHR
Weather
     

 

Frequency Bands

High Frequency (HF) - (3 - 30 MHz)

Very High Frequency (VHF) - (30 - 300 MHz)

Ultra High Frequency (UHF) - (300 MHz - 3 GHz)

 

High Band - (25.00 - 27.36 MHz)
25.020 - 25.320 IND
25.870 - 26.470 RTV
26.62 CAP
26.966 - 27.405 CB
27.430 - 27.630 BUS

 

10-Meter Amateur Band - (28.0 - 29.7 MHz)
28.000 - 29.700 HAM

 

Low Band - (29.7 - 50 MHz - in 5 kHz steps)

29.700 - 29.790 IND
29.900 - 30.550 GOVT, MIL
30.580 - 31.980 IND, PUB
32.000 - 32.990 GOVT, MIL
33.020 - 33.980 BUS, IND, PUB
34.010 - 34.990 GOVT, MIL
35.020 - 35.980 BUS, PUB, IND, TELM
36.000 - 36.230 GOVT, MIL
36.250 Oil spill clean up
36.270 - 36.990 GOVT, MIL
37.020 - 37.980 PUB, IND
38.000 - 39.000 GOVT, MIL
39.020 - 39.980 PUB
40.000 - 42.000 GOVT, MIL, MARI
42.020 - 42.940 POL
42.960 - 43.180 IND
43.220 - 43.680 TELM, IND, PUB
43.700 - 44.600 TRAN
44.620 - 46.580 POL, PUB
46.600 - 46.990 GOVT, TELC
47.020 - 47.400 PUB
47.420 American Red Cross
47.440 - 49.580 IND, PUB
49.610 - 49.990 MIL, TELC

 

6-Meter Amateur Band (50 - 54 MHz)

50.00 - 54.00 HAM

 

FM-TV Audio Broadcast, Wide Band (54 - 72 MHz)
59.750 TV Channel 2
65.750 TV Channel 3
71.750 TV Channel 4

 

Land Mobile Service Band (72 - 76 MHz)

 

FM-TV Audio Broadcast, Wide Band (76 - 88 MHz)
81.750 TV Channel 5
87.750 TV Channel 6

 

FM Radio Broadcast, Wide Band (88 - 108 MHz)

 

Aircraft Band (108 - 136 MHz)
108.000 - 121.490 AIR
121.500 AIR Emergency
121.510 - 136.000 AIR

 

U. S. Government Band (138 - 144 MHz)
137.000 - 144.000 GOVT, MIL

 

VHF-Hi Band (148 - 174 MHz)
148.050 - 150.345 CAP, MARS, MIL
150.775 - 150.790 MED
150.815 - 150.965 TOW
150.980 Oil Spill Clean Up
150.995 - 151.130 ROAD
151.145 - 151.475 POL
151.490 - 151.955 IND, BUS
151.985 TELM
152.030 - 152.240 TELB
152.270 - 152.465 IND, TAXI
152.480 BUS
152.510 - 152.840 TELB
152.870 - 153.020 IND, MOV
153.035 - 153.175 IND, OIL, UTIL
153.740 - 154.445 PUB, FIRE
154.490 - 154.570 IND, BUS
154.585 Oil Spill Clean Up
154.600 - 154.625 BUS
154.665 - 156.240 MED, ROAD, POL, PUB
165.255 OIL
156.275 - 157.425 MARI
157.450 MED
157.470 - 157.515 TOW
157.530 - 157.725 IND, TAXI
157.740 BUS
157.770 - 158.100 TELB
158.130 - 158.460 BUS, IND, OIL, TELM, UTIL
158.490 - 158.700 TELB
158.730 - 159.465 POL, PUB, ROAD
159.480 OIL
159.495 - 161.565 TRAN
161.580 OIL
161.600 - 162.000 MARI, RTV
162.0125 - 162.35 GOVT, MIL, USXX
162.400 - 162.550 WTHR
162.5625 - 162.6375 GOVT, MIL, USXX
162.6625 MED
162.6875 - 163.225 GOVT, MIL, USXX
163.250 MED
163.275 - 166.225 GOVT, MIL, USXX
166.250 GOVT, RTV, FIRE
166.275 - 169.400 GOVT, BIFC
169.445 Wireless Microphones
169.500 GOVT
169.505 Wireless Microphones
169.55 - 169.9875 GOVT, MIL, USXX
170.000 BIFC
170.025 - 170.150 GOVT, RTV, FIRE
170.175 - 170.225 GOVT
170.245 - 170.305 Wireless Microphones
170.350 - 170.400 GOVT, MIL
170.425 - 170.450 BIFC
170.475 PUB
170.4875 - 173.175 GOVT, PUB, Wireless Microphones
173.225 - 173.375 MOV, NEWS, UTIL
173.3875 - 178.5375 MIL
173.5625 - 173.5875 MIL Medical/Crash Crews
173.60 - 173.9875 GOVT

 

FM-TV Audio Broadcast, VHF Wide Band (174 - 216 MHz)
179.750 TV Channel 7
185.750 TV Channel 8
191.750 TV Channel 9
197.750 TV Channel 10
203.750 TV Channel 11
209.750 TV Channel 12
215.750 TV Channel 13

 

New Mobile Narrow Band (220 - 222 MHz)
220.000 - 222.000 NEW

 

1.3-Meter Amateur Band (222 - 225 MHz)
222.000 - 225.000 HAM

 

Military Aircraft Band (237.9 - 287.8 MHz)
237.900 Coast Guard Search & Rescue
239.800 FAA Weather
241.000 Army Aircraft
243.000 Military Aircraft Emergency
255.400 FAA Flight Service
257.800 Civilian Towers
287.800 Coast Guard Air/Sea Rescue

 

Military Aircraft Band (319.1 - 383.9 MHz)
319.100 FAA Traffic Control
321.000 - 336.600 Air Force
342.500 - 344.600 FAA Weather
346.400 - 364.200 Air Force Traffic Control
381.800 - 383.900 Coast Guard

 

U.S. Government Band (406 - 420 MHz)
406.125 - 419.975 GOVT, USXX

 

70-cm Amateur Band (420 - 450 MHz)
420.000 - 450.000 HAM

 

Low Band (450 - 470 MHz)
450.050 - 450.925 RTV
451.025 - 452.025 IND, OIL, TELM, UTIL
452.0375 - 453.00 IND, TAXI, TRAN, TOW, NEWS
453.0125 - 453.9875 PUB
454.000 OIL
454.025 - 454.975 TELB
455.050 - 455.925 RTV
457.525 - 457.600 BUS
458.025 - 458.175 MED
460.0125 - 460.6375 FIRE, POL, PUB
460.650 - 462.175 BUS
462.1875 - 462.450 BUS, IND
462.4625 - 462.525 IND, OIL, TELM, UTIL
462.550 - 462.725 GMR
462.750 - 462.925 BUS
462.9375 - 463.1875 MED
463.200 - 467.925 BUS

 

Family Radio Service (462.5625 - 467.7125 MHz)
(Channels 1 - 14)
462.5625 FRS Channel 1
462.5875 FRS Channel 2
462.6125 FRS Channel 3
462.6375 FRS Channel 4
462.6625 FRS Channel 5
462.6875 FRS Channel 6
462.7125 FRS Channel 7
467.5625 FRS Channel 8
467.5875 FRS Channel 9
467.6125 FRS Channel 10
467.6375 FRS Channel 11
467.6625 FRS Channel 12
467.6875 FRS Channel 13
467.7125 FRS Channel 14

 

FM-TV Audio Broadcast, UHF Wide Band (470 - 805.750 MHz)
(Channels 14 - 69 in 6 MHz steps)
475.750 TV Channel 14
481.750 TV Channel 15
487.750 TV Channel 16
493.750 TV Channel 17
499.750 TV Channel 18
505.750 TV Channel 19
511.750 TV Channel 20
517.750 TV Channel 21
523.750 TV Channel 22
529.750 TV Channel 23
535.750 TV Channel 24
541.750 TV Channel 25
547.750 TV Channel 26
553.750 TV Channel 27
559.750 TV Channel 28
565.750 TV Channel 29
571.750 TV Channel 30
577.750 TV Channel 31
583.750 TV Channel 32
589.750 TV Channel 33
595.750 TV Channel 34
601.750 TV Channel 35
607.750 TV Channel 36
613.750 TV Channel 37
619.750 TV Channel 38
625.750 TV Channel 39
631.750 TV Channel 40
637.750 TV Channel 41
643.750 TV Channel 42
649.750 TV Channel 43
655.750 TV Channel 44
661.750 TV Channel 45
667.750 TV Channel 46
673.750 TV Channel 47
679.750 TV Channel 48
685.750 TV Channel 49
691.750 TV Channel 50
697.750 TV Channel 51
703.750 TV Channel 52
709.750 TV Channel 53
715.750 TV Channel 54
721.750 TV Channel 55
717.750 TV Channel 56
733.750 TV Channel 57
739.750 TV Channel 58
745.750 TV Channel 59
751.750 TV Channel 60
757.750 TV Channel 61
763.750 TV Channel 62
769.750 TV Channel 63
775.750 TV Channel 64
781.750 TV Channel 65
787.750 TV Channel 66
793.750 TV Channel 67
799.750 TV Channel 68
805.750 TV Channel 69

Note: Some cities use the 470 - 512 MHz band for land/mobile service.

 

Conventional Systems Band - Locally Assigned
851.0125 - 855.9875 CSB

 

Conventional/Trunked Systems Band - Locally Assigned
856.0125 - 860.9875 CTSB

 

Trunked Systems Band - Locally Assigned
861.0125 - 865.9875 TSB

 

Public Safety Band - Locally Assigned
866.0125 - 868.9875 PSB

 

Common Carrier
869.010 - 894.000 CCA

 

Private Trunked
935.0125 - 939.9875 PTR

 

General Trunked
940.0125 - 940.9875 GTR
 

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Frequency Conversion

The tuning of a station can be expressed in frequency (kHz or MHz) or in wavelength (meters). The following information can help you make the necessary conversions.

To convert MHz to kHz, multiply by 1,000:

To convert from kHz to MHz, divide by 1,000

To convert MHz to meters, divide 300 by the number of megahertz

 

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Image Reception

Radios work by simple mathematics. For example, most tune to a frequency by mixing that frequency with another (local oscillator) frequency which is slightly different. This mixing process primarily gives us the two original frequencies, their sum, and their difference. Well, the radio's Intermediate Frequency (IF) filter normally passes either the sum or difference frequency, and this is then processed into the sound we hear. Because nothing is perfect, certain "harmonics" will also get through if they are strong enough. For example, if a radio's IF is 10.7 MHz, we might be able to tune to a frequency 21.4 MHz (2 x IF) above (or below, depending on the radio's design) a strong signal and hear it! This is more evident in a dual-conversion radio than a triple-conversion radio, because the triple-conversion radio's 1st intermediate frequency is quite high. This causes the image to be so far off frequency that it is easy to effectively filter it out.

Just because a radio doesn't receive something which another does is not necessarily an indication of a problem. The one radio may simply not be "tricked" into picking up an image! This rejection of undesired signals is one reason that a triple-conversion receiver costs more than a similar dual-conversion model. If you are more interested in finding more out about radios and radio operation, a good location to start looking is your local public library. You might also wish to contact the ARRL, as they are an excellent source of informative texts on the subject.

 

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Additional On-line Information

ARRL
Amateur Radio Relay League

http://www.arrl.org/

Strong Signals
(by Richard J. Wells, N2MCA)
http://www.strongsignals.net/
TrunkTracker™
(by Uniden)
http://www.trunktracker.com/
 

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Glossary

Base Station: A scanner or other two-way radio which is non-mobile, often connected to a larger, outdoor antenna.
Birdie: A false/unwanted signal produced inside the scanner.
Channel: A memory location used to store a single frequency.
Conventional Scanning: Following conversations that are broadcast on manually tuned radios.
Crystal: A component which allows a crystal-controlled scanner to receive a particular frequency.
dB, decibel: Unit used to express relative differences in noise level or signal strength.
Discone: An antenna which has the horizontal elements connected to the shield and the cone connected to the coax center conductor, so that the actual configuration is an upside down half-bow-tie.
Dual-conversion: A method using a receive circuit with two stages and two intermediate frequencies to extract the data signal from the carrier.
Frequency: The number of cycles (Hertz) used as a carrier for a particular data signal.
Frequency Band: A particular frequency range used for a particular purpose.
Frequency Step: The increment between displayed frequencies on a digitally-tuned scanner.
Harmonic: Describes a frequency which has a smaller amplitude and is a multiple of a larger frequency (for example, 480 MHz is the second harmonic of 240 MHz and the third harmonic of 120 MHz).
Hyperscan: A faster scan method available on some scanners.
GHz (gigahertz): A unit of frequency equal to 1000 MHz, 1,000,000 kHz or 1,000,000,000 Hz.
Hz (Hertz): A unit of frequency equal to one cycle per second.
Image: A "false" signal generated by the scanner during reception and demodulation.
Intermediate Frequency (IF): A frequency used in the demodulation process (see Dual-conversion and Triple-conversion).
kHz (kilohertz): A unit of frequency equal to 1000 Hz.
Lock-out: To mark a channel to not be scanned.
MHz (megahertz): A unit of frequency equal to 1000 kHz or 1,000,000 Hz.
Priority Channel: A channel which is scanned regularly during normal scanning.
Reset: Return the scanner to factory settings.
Reinitialize: Return the scanner to factory settings.
RX: Shorthand for Receive or Receiving.
Scanner: A radio that can tune quickly and/or automatically to a wide range of frequencies used by hobbyists to monitor police, fire, and other emergency services.
Service Band: A particular frequency range used for a particular purpose.
SMR: Acronym for "Service Maintenance Repeater", indicating that radio operators must be a member of that club to transmit to that repeater.
Squelch: Allows you to set the minimum strength signal that will be received.
Super-heterodyne: Describes a transmitting encoding method which mixes a carrier and oscillator frequency.
Triple-conversion: A method using a receive circuit with three stages and three intermediate frequencies to extract the data signal from the carrier.
Trunk tracking: Following conversations that are broadcast on radios automatically tuned by a computer.
TX: Shorthand for Transmit or Transmitting.
UHF: The frequencies between 300 MHz and 3 GHz.
VHF: The frequencies between 30 MHz and 300 MHz.
 

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