Difference between revisions of "Realistic PRO-41 Scanner"

Revision as of 11:27, 5 June 2015

RadioShack PRO-41 10 Channel Programmable Scanner
Realistic PRO-41 Direct Entry Programmable Scanner

Care and Maintenance

Your PRO-41 is an example of superior design and craftsmanship. The following suggestions will help you care for the scanner so that you can enjoy it for years.

Keep the scanner dry. If it does get wet, wipe it dry immediately. Liquids can contain minerals that can corrode the electronic circuit.

Use and store the scanner only in normal temperature environments. Temperature extremes can shorten the life of electronic devices, damage batteries, and distort or melt plastic parts.

Handle the scanner gently and carefully. Dropping it can damage circuit boards and cases and can cause the scanner to work improperly.

Keep the scanner away from dust and dirt, which can cause premature wear of parts.

Wipe the scanner with a dampened cloth occasionally to keep it looking new. Do not use harsh chemicals, cleaning solvents, or strong detergents to clean the product.

Use only fresh batteries of the recommended size and type. Always remove old or weak batteries. They can leak chemicals that destroy electronic circuits.

Modifying or tampering with the scanner's internal components can invalidate the product's warranty and might void your FCC authorization to operate it. If your product is not performing as it should, take it to your local Radio Shack store. Our personnel can assist you and arrange

Features

INTRODUCTION

The PRO-41 Programmable Scanner lets you hear all the action. This scanner lets you access over 20,000 frequencies that include the police department, fire department, ambulance service, amateur radio, and transportation services. You can store frequencies in the scanner's 10 channels and you can change your selections at any time.

The secret to the scanner's ability to scan so many frequencies is its custom-designed microprocessor - a tiny, built-in computer. The scanner's microprocessor also gives the scanner these features:

• Liquid-Crystal Display - shows the selected channel and frequency.
• Automatic 3-Second Scan Delay - helps keep you from missing replies on a channel while you are scanning.
• Memory Backup - keeps the channel frequencies stored in the scanner's memory for up to 30 minutes without the batteries.
• Low Battery Alarm - lets you know when the batteries get low.

The PRO-41 covers all these bands:

 29-50 MHz (VHF Lo)                                  148 -174 MHz(VHF-Hi)
 50-54 MHz (6-Meter Ham Band)                  406-450 MHz (ham radio and
                                                              government)
 137-144 MHz (Government)                            450-470 MHz (UHF Lo)
 144-148 MHz (2-Meter Ham Band)                      470-512 MHz (UHF Hi)

The scanner might cause radio or TV interference, even when it is operating properly. To determine whether the scanner is causing the interference, turn off the scanner. If the interference goes away, the scanner is causing the interference. Try to eliminate the interference by:

1. Moving the scanner away from the receiver
2. Contacting your local Radio Shack store for help
3. If you cannot eliminate the interference, the FCC requires that you stop using the scanner.

(br-7/15/94)

General Guide To Scanning

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 hear only noise on that frequency.

If the interference is not severe, you might be able to turn SQUELCH clockwise 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

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 thousand 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 three frequencies - 162.40, 162.475 or 162.55 MHz. In most areas of the country, you can receive one of these frequencies.

A Guide To The Action Bands

With the right frequencies programmed into your PRO-Series 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 the bands you 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 you local RadioShack store.

Abbreviations:

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

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.

Guide To Frequencies

National Weather Frequencies:

1) 161.650              5) 162.440              9) 162.525
2) 161.775              6) 162.450             10) 162.550
3) 162.400              7) 162.475             11) 163.275
4) 162.425              8) 162.500

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                        Frequency
(Meters)                            (MHz)

10-meter                        28.000-29.700
6-meter                         50.000-54.000
2-meter                        144.000-148.000
70-cm                          420.000-450.000

The following are the channels and frequencies of the Citizens Band:

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

Guide To The Action Bands

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

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

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.

Typical Band Usage

HF Band (3.0 - 30.0 MHz):

Mid Range: ............................................. 25.00 - 28.63 MHz
10-Meter Amateur Band: ................................. 28.00 - 29.70 MHz
High Range: ............................................ 29.70 - 29.90 MHz

VHF Band (30.00 - 300.0 MHz):

Low range: ............................................. 30.00 - 50.00 MHz
6-Meter Amateur: ....................................... 50.00 - 54.00 MHz
FM-TV Audio Broadcast, Wide Band: ...................... 54.00 - 72.00 MHz
FM Radio Broadcast, Wide Band: ........................ 88.00 - 108.00 MHz
Aircraft: ............................................ 108.00 - 136.00 MHz
U.S. Government: ..................................... 138.00 - 144.00 MHz
2-Meter Amateur: ..................................... 144.00 - 148.00 MHz
High Range: .......................................... 148.00 - 174.00 MHz
New Mobile Narrow Band: .............................. 220.00 - 222.00 MHz
1.3-Meter Amateur: ................................... 222.00 - 225.00 MHz
Military Aircraft: ................................... 225.00 - 287.80 MHz

UHF Band (300.00 MHz - 3.0 GHz):

Military Aircraft: ................................... 311.00 - 384.00 MHz
U.S. Government: ..................................... 406.00 - 470.00 MHz
0.6-Meter Amateur: ................................... 420.00 - 450.00 MHz
Low Range: ........................................... 450.00 - 470.00 MHz
FM-TV Audio Broadcast, Wide Band: .................... 470.00 - 806.00 MHz
Conventional Systems: ................................ 851.00 - 856.00 MHz
Conventional/Trunked Systems: ........................ 856.00 - 861.00 MHz
Trunked Systems: ..................................... 861.00 - 866.00 MHz
Public Safety: ....................................... 866.00 - 869.00 MHz
Common Carrier: ...................................... 869.00 - 894.00 MHz
Private Trunked: ..................................... 935.00 - 940.00 MHz
General Trunked: ..................................... 940.00 - 941.00 MHz

Primary Usage:

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

VHF Band:

2-Meter Amateur Band: .............................. 144.000 - 148.000 MHz
Government, police, and Fire: ...................... 153.785 - 155.980 MHz
Emergency Services: ................................ 158.730 - 159.460 MHz
Railroad: .......................................... 160.000 - 161.900 MHz

UHF Band:

.6 cm Amateur Band FM Repeaters: ................... 440.000 - 450.000 MHz
Land Mobile "Paired" Frequencies: .................. 450.000 - 470.000 MHz
Base Stations: ..................................... 451.025 - 454.950 MHz
Mobile Units: ...................................... 456.025 - 459.950 MHz
Repeater Units: .................................... 460.025 - 464.975 MHz
Control Stations: .................................. 465.025 - 469.975 MHz

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.

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: ................................................... 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
TELBL: .................................................. 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

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

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

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: .............................................................. TV2
65.750: .............................................................. TV3
71.750: .............................................................. TV4

Land Mobile Service Band (72-76 MHz):

FM-TV Audio Broadcast, Wide Band (76-88 MHz):

81.750: .............................................................. TV5
87.750: .............................................................. TV6

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 MIKES
169.500: ............................................................ GOVT
169.505: .................................................. WIRELESS MIKES
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 MIKES
170.350 - 170.400: ............................................. GOVT, MIL
170.425 - 170.450: .................................................. BIFC
170.475: ............................................................. PUB
170.4875 - 173.175: ............................ GOVT, PUB, WIRELESS MIKES
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: ............................................................. TV7
185.750: ............................................................. TV8
191.750: ............................................................. TV9
197.750: ............................................................ TV10
203.750: ............................................................ TV11
209.750: ............................................................ TV12
215.750: ............................................................ TV13

New Mobil 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
243.000: ....................................................... EMERGENCY
255.400: .............................................. FAA FLIGHT SERVICE
257.800: ................................................. CIVILIAN TOWERS
287.800: ............................................. Coast Guard Air/Sea 
Rescue

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

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

FM-TV Audio Broadcast, UHF Wide Band (470-512 MHz):
(Channels 14-69 in 6 MHz steps):

475.750: ...................................................... Channel 14
481.750: ...................................................... Channel 15
487.750: ...................................................... Channel 16
805.750: ...................................................... 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

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.

• 1 MHz (million)=1,000 kHz (thousand)

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

• 9.62 MHz x 1000 = 9620 kHz

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

• 2780 kHz / 1000 = 2.780 MHz

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

• 300 / 7.1 MHz = 42.25 meters

A Note on 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 (I.F.) 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 I.F. is 10.7 MHz, we might be able to tune to a frequency 21.4 MHz (2 x I.F.) above (or below, depending on the radio's design) a strong signal and hear it! This is more evident in a double-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.

So remember that 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.

You might be interested in finding more out about radio. One good location to start looking is your local public library. You might also wish to contact the A.R.R.L., as they are an excellent source of informative texts on the subject.

Contact:

Amateur Radio Relay League
225 Main St.,
Newington, CT 06111-1494
USA

(CD EB 2/22/00)

Operation

SETTING THE VOLUME AND SQUELCH CONTROLS

Rotate VOLUME clockwise and SQUELCH counterclockwise until you hear a hissing sound. Then, slowly rotate SQUELCH clockwise until the noise stops. Set VOLUME to a comfortable level.

If the scanner picks up unwanted weak transmissions, rotate SQUELCH clockwise to decrease the scanner's sensitivity to signals.

USING THE KEY LOCK

Once you program the scanner, you can protect it from accidental program changes by moving the lock SWITCH to IN. In this position, the only controls that operate are VOLUME, SQUELCH, MANUAL, and SCAN.

When you want to change the scanner's programming, move the LOCK switch to OUT.

PROGRAMMING THE SCANNER

Follow these steps to store frequencies in channels.

1. Select a channel to program by pressing MANUAL, entering the channel number you want to program, and pressing MANUAL.

2. Enter a frequency.

To enter the decimal, press ./CLEAR. The decimal point is displayed as a dash (-) on the display.

3. Press ENTER to store the frequency.

If you made a mistake in Step 2, E appears on the display. Press ./CLEAR twice and repeat Step 2.

4. To confirm the proper entry, press REVIEW. The programmed frequency appears on the display, one digit at a time.

5. To program more channels, repeat Steps 1 to 3. If you want to program the next channel in sequence, simply press MANUAL and repeat Steps 2-4.

Tips for Programming

A good reference for active frequencies is Radio Shack's Police Call Directory including Fire and Emergency Services.

We update this directory every year, so be sure to get a current copy.

Frequencies in the VHF bands are in 5 kHz steps. In the UHF bands, they are in 12.5 kHz steps. The scanner automatically rounds the frequency to the nearest valid number. For example, if you try to enter a frequency of 151.373, your scanner accepts it as 151.475.

SCANNING THE CHANNELS

To begin scanning the channels, press SCAN. The scanner scans through all the channels except the ones you have locked out. Be sure to read the following sections to get the full benefit from the scanner's special features.

LOCKING OUT CHANNELS

You can make the scanner scan more efficiently by locking out channels that you have not programmed. Enter the channel number you wish to lock out, press MANUAL and then press LOCK OUT so that the LOCK OUT indicator lights. This is also handy for locking out channels that have a continuous transmission. You can still manually select locked out channels for listening.

To unlock a channel you have locked, manually select the channel and press LOCK OUT so that the LOCK OUT indicator goes off.

MANUALLY SELECTING A CHANNEL

You can continuously monitor a single channel without scanning. This is useful if you hear an emergency broadcast on a channel and do not want to miss any of the details - even though there might be periods of silence - or if you want to monitor a channel that you have locked out.

To select a channel to monitor, press MANUAL and advance through the channels by pressing MANUAL repeatedly, or move directly to a channel by entering the channel number on the keypad then pressing MANUAL. If the scanner is scanning and has stopped at the desired channel, press MANUAL one time.

AUTOMATIC SCAN DELAY

The scanner stops when it finds a signal. It begins scanning other channels about 3 seconds after the signal ends. The 3-second delay gives you a chance to receive a reply to the first signal.

A GENERAL GUIDE TO SCANNING

BIRDIES

Birdies are the products of internally generated signals that make some frequencies difficult or impossible to receive. If you program one of these frequencies, you hear only noise on that frequency.

If the interference is not severe, you might be able to cut out the birdie by turning the squelch control clockwise. The most common birdies to watch for are listed below.

         30.300 MHz
         31.200 MHz
         32.500 MHz
         41.600 MHz
         52.000 MHz

RECEPTION NOTES

The scanner receives signals that are mainly "line of sight." That means that you usually cannot hear stations at your listening location that extend beyond the horizon.

During the summer, you might hear stations in the 30-50 MHz range located several hundred or even thousands of miles away. This phenomenon is known as skip, and is caused by summer atmospheric conditions. This type of reception is unpredictable but often very interesting.

One useful service is the National Oceanic Atmospheric Administration (NOAA) Weather Radio's continuous weather broadcasts. These broadcasts advise you of the current weather conditions, weather predictions, and also contain information about any threatening weather. These stations use three frequencies - 162.40, 162.475, and 162.55 MHz. In most areas of the country, you can receive one or more of these frequencies.

GUIDE TO THE ACTION BANDS

With the right frequencies programmed into the 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 the most dangerous thing you could ever do.

Find out if there is a local club that monitors these frequencies. Perhaps a local electronics repair shop that works on similar equipment can give you the frequencies used by local radio services. A volunteer police or fire employee can also be a good source of this information.

As a general rule on VHF, most activity is between 153.73 and 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 between 160.0 and 161.9 MHz for signals.

In some larger cities, there has been a move to the UHF bands for these emergency services. Here, most of the activity is between 453.025 and 453.95 MHz and again between 456.025 and 459.95 MHz.

In the UHF band, the range between 456.025 and 459.95 MHz and again between 465.025 and 469.975 MHz is used by mobile units and control stations associated with base and repeater units that operate 5 MHz lower (that is, between 451.025 and 454.95 and between 460.025 and 464.975 MHz). This means that if you find an active channel inside one of these spreads, you can look 5 MHz lower (or higher, as the case may be) to find the major base station/repeater for that radio service.