PRO-2026 (200-0148) A General Guide to Scanning Faxback Doc. # 7923
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 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
31.050 MHz
32.400 MHz
36.225 MHz
41.400 MHz
46.575 MHz
51.750 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 might 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 condition. This type of reception is
unpredictable but often very interesting!
GUIDE TO THE ACTION BANDS
With a little investigation, you can find the active frequencies in your
community. We can give you some general pointers on finding these
frequencies 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
services. A volunteer police department or fire department employee can
also be a good source for this information.
As a general rule on VHF, most activity concentrates between 153.785 and
155.98 MHz and between 153.73 and 159.45 MHz. Here you find local
government, police, fire, and most other emergency services. If you are
near major railroad tracks, listen between 160.0 and 161.9 for signals.
In some larger cities, there has been a move to the UHF bands for
emergency services. Here, most of the activity is between 453.025 and
453.95 MHz and between 456.025 and 459.95 MHz.
In the UHF band, mobile units operate between 456.025 and 459.95 MHz and
between 465.025 and 469.975 MHz. A repeater picks up the mobile units'
transmissions on one frequency, then rebroadcasts (or repeats) the
transmission 5 MHz lower, but at a higher power level, than the mobile
units (that is 451.025-454.95 MHz and 460.025-464.975 MHz). This means
that if you find an active frequency inside one of the mobile unit's
frequency spreads, you can look 5 MHz lower to find the repeater
frequency.
A system called trunked radio lets several services use the same set of
frequencies in the 800 MHz band without interference. Several frequencies
are allocated to two or more services (like fire, police, and water
departments). As each service transmits, a separate control signal
activates other radios in the same service, so that only that service
hears the transmission. The frequency is selected as soon as the unit
begins to transmit, and could be any one of the allocated frequencies.
One very useful service is the National Weather Service's continuous
weather broadcasts. These broadcasts contain weather forecasts and data
for the area around the station, plug 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.
TYPICAL BAND USAGE
The following is a brief listing of the services that typically use the
bands received by your scanner. This listing can help you decide which
ranges you would like to scan.
Abbreviations:
Affiliate Radio System....MARS 35.02-35.18..................Bus.
Amateur...................Ham 35.22-35.66......Mob. Tel. & Page
Automobile Emergency......Auto Emer. 35.70-35.72..................Bus.
Broadcast Remote..........BC.R. 35.74-35.98.......Sp. Ind. & Bus.
Bureau of Reclamation.....Bur. Recl. 36.00-37.00.................Govt.
Civil Air Patrol..........CAP 37.02-37.44.......P.D. & L. Govt.
Department of Agriculture 37.46-37.86.................Power
and Forestry..............Agr. and For. 37.90-37.98......Hwy. & Sp. Emer.
Fire Department...........F.D. 38.00-39.00.................Govt.
Forest Products...........For. Prod. 39.02-39.98.......P.D. & L. Govt.
Forestry Conservation.....Fors. Cons. 40.00-42.00.................Govt.
Government................Govt. 42.02-42.94..............St. P.D.
Highway Maintenance.......Hwy. 42.96-43.18.......Sp. Ind. & Bus.
Land Transportation.......Land Tr. 43.22-43.68........Mob. Tel. Page
Local Government..........L. Govt. 43.70-44.60..........Trucks. Bus.
Manufacturers.............Mfg. 44.62-45.06...St. P.D. For. Cons.
Military..................MIL 45.08-45.66..................P.D.
Mobile Telephone..........Mob. Tel. 45.68-46.04...P.D. Hwy.,Sp. Emer.
Motion Picture............Mot. P. 46.06-46.50..................F.D.
Motor Carrier.............Buses. Trucks 46.52-46.58..............L. Govt.
National Parks............Nat. Park 46.60-47.00.................Govt.
Petroleum.................Pet. 47.02-47.40..............St. Hwy.
Police....................P.D. 47.42...................Red Cross
Power Utilities...........Power 47.44-47.68....Sp. Ind. Sp. Emer.
Radio Paging..............Page 47.70-48.54.................Power
Railroad..................R.R. 48.56-49.58.......For. Prod.,Pet.
Relay Press 49.60-50.00.................Govt.
State Police..............St. P.D. 50.00-54.00.......6 Meter Amateur
Special Emergency.........Sp.Ind (Ham) Band
Taxicab Radio.............Taxi
Telephone Maintenance.....Tel. Maint. 108-136.975 MHz BAND
U.S. Coastal and 108.000-118.000....Air Navagation
Geodetic Survey...........U.S.C.G.S. 118.000-136.975..........Aircraft
U.S. Navy.................USN
U.S. Weather Bureau.......U.S.W.B. 137-174 MHz BAND
137.000-144.000.............Govt.
29-54 MHz BAND 144.000-148.000...............HAM
29.00-29.70.............10-meter HAM 148.010......................MARS
29.70-29.80...............For. Prod. 148.150.......................CAP
29-80-30.00....................Aero. 148.155-148.250...............MIL
30.01-30.56....................Govt. 148.290-150.750...............USN
30.56-30.62.................Sp. Ind. 150.815-150.995..............Bus.
30.66-31.24.........Ind. (Pet., For. 151.010-151.130...............HWY
Cons., Bus., for. Prod.) 151.145-151.475.......Fors. Cons.
31.26-31.98.....Sp. Ind., For. Cons. 151.505-151.595..........Sp. Ind.
32.00-33.00....................Govt. 151.625-151.955..............Bus.
33.02-33.16....Hwy., Sp. Emer., Bus. 151.985-152.240...Mob. Tel. (RCC)
33.18-33.38.....................Pet. 152.270-152.450..............Taxi
33.42-33.98.....................F.D. 152.480-152.840....Mob. Tel. Page
34.00-35.00....................Govt. 152.870-153.020...Sp.Ind. Mot. P.
153.050-153.440.....Pet., For. Prod. 451.775-451.975.........Spec. Ind.
153.740-154.115.............L. Govt. 452.000-452.500.........Taxi, Mot.
154.130-154.445.................F.D. Carrier, R.R.
154.450-154.600...Sp.Ind., Pet. Bus. 452.525-452.600..........Auto Club
154.655-155.145.P.D.,L.Govt.,St.P.D. 452.625-452.975..L.Govt.,P.D.,F.D.
155.160-155.400.......Sp. Emer. P.D. 454.000-454.975..........Mob. Tel.
155.415-156.030.......P.D., L. Govt. 455.000-455.975.........Remote Br.
156.045-156.240...........Hwy., P.D. 456.000-458.975....P.D.,F.D.,Ind.,
156.275-157.425...............Marine Lan. Tr.
157.456-157.500...........Auto Emer. 459.000-459.975....Domestic Public
157.530-157.710.................Taxi 460.000-460.625.........P.D., F.D.
157.740-158.100.......Mob. Tel. Page 460.650-462.175...............Bus.
158.130-158.460.Power,For. Prod.,Pet 462.200-462.450...............Taxi
158.490-158.700......Mob. Tel. (RCC) 462.750-462.975...............Bus.
158.730-158.970.......P.D., L. Govt. 463.000-463.175............Medical
158.985-159.210............P.D. Hwy. 463.200-464.975...............Bus.
159.225-159.465...........For. Cons. 465.000-467.500...P.D., F.D.,Ind.,
159.510-160.200...............Trucks Land Tr.
160.215-161.565.................R.R. 467.750-467.925...............Bus.
161.600-162.000...............Marine 467.7375-469.975.Pub. Safety, Ind.
162.026-162.175...........Bur. Recl. Land Tr.
162.400.....................U.S.W.B.
162.550.....................U.S.W.B. TV Bands for Special Communications
163.125...............Indian Affairs 470-476 T. V. Channel 14
163.275.....................U.S.W.B. 476-483 T. V. Channel 15
163.388-163.538..................MIL 482-488 T. V. Channel 16
163.825-163.975................Govt. 488-494 T. V. Channel 17
164.025-164.075...........U.S.C.G.S. 494-500 T. V. Channel 18
164.175-165.188..Bur. Recl. Nat. Pk. 500-506 T. V. Channel 19
Govt., Agr. & For. 506-512 T. V. Channel 20
169.300.......................F.A.A.
169.450-169.725............Ind. Data 6 MHz Segment is allocated for
170.150.................F.D., BC. R. Channel 14
170.200-170.220...........U.S.C.G.S. 470.0125-470.2875..Domestic Public
170-225-170.325.......Ind. Land. Tr. (Base, Mob.)
170.425-170.575...........For. Cons. 470-3125-471.1375....Public Safety
170.975-171.250.Govt. Ind., Land Tr. 471.1625-471.2875...Reserve Pool A
171.388-172.725.....Bur. Recl., For. 471.3125-471.4125..Pwr. Tel. Maint
Cons., Ind., Dept. Ag. 471.4375-471.6375.......Spec. Ind.
& For., Govt. 471.6625-471.7875...Reserve Pool B
172.775.....................Nat. Pk. 471.8125-472.3375.............Bus.
173.025.....................U.S.W.B. 472.3625-472.4375.............Taxi
173.075...................U.S.C.G.S. 475.4625-475.7875......R.R. Motor
173.204.....Mot.P., Pet., Bur. Recl. Carrier, Auto Emer.
Press Relay. 472.8125-472.9875.......Pet., For.
Prod., Mfg.
406-512 MHz BAND 473.0125-473.2875..Domestic Public
406.000-420.000................Govt. 473.3122-474.1375....Public Safety
420.000-450.000..................HAM 474.1625-474.2875...Reserve Pool A
450.050-450.950...........Remote Br. 474.3125-474.4125..Pwr. Tel. Maint
451.000-451.150................Util. 474.4375-474.6375.......Spec. Ind.
451.175-451.750....For. Prod., Pet., (Mobile)
Power, Tel. Maint. 474.6625-474.7875..Reserve Pool B
474.8125-475.3375................Bus.
475.3625-475.4375................Taxi
475.4625-475.7875........R.R., Motor
Carrier, Auto Emer.
475.8125-475.9876...Pet., For. Prod.,
Mfg.
806-947 MHz BAND
806.000-816.000.......Domestic Public
(Mobile)
816.000-821.000.......Mobile Trunking
851.000-861.000.......Domestic Public
(Base)
861.000-866.000.........Base Trunking
902.000-928.000.Industrial Scientific
These frequencies are subject to change and might vary some from area to
area. For a more complete listing, refer to the Police Call Radio Guide
Including Fire and Emergency Services at your local Radio Shack store.
You might discover one of your regular stations on a frequency that is not
listed. This could be what is known as an "image." For example, if you
find a station on 453.2750 that you also hear on 474.8750, do a little
math to see if it is an image. Take the intermediate frequency of 10.8
MHz and double it (21.6 MHz). Then subtract 21.6 MHz from the "new"
frequency. If the answer is the normal frequency, you have tuned to an
image. Occasionally, you might get interference on a weak or distant
channel from a strong broadcast 21.6 MHz (2 x 10.8 MHz) below the tuned
frequency. this is rare, and the image signal is usually cleared whenever
a broadcast on the actual frequency is in progress.
(ALL-11/08/94)