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)