| Hearing the USA (in 2002!) |
| U.S. Low VHF Bandplan |
| Steps of 20 kilohertz NFM. FROM TO ALLOCATION 30.000 30.560 US Government 30.560 31.980 Business/ Industry/ Forestry 31.990 32.000 Public Safety 32.000 33.000 US Government 33.000 33.100 Public Safety 33.120 33.400 Business/ Petroleum 33.420 34.000 Fire 34.000 35.000 US Government 35.020 36.000 Paging/ Business 36.000 37.000 US Government 37.020 37.420 Police/ Local Government 37.460 37.860 Power/ Water/ Pipeline 37.900 38.000 Highway maintenance/ Special Emergency 38.000 39.000 US Government 39.020 40.000 Police/ Local Government 40.000 42.000 US Government 42.020 42.940 State Police 42.960 43.680 Business/ Paging 43.700 44.600 Transportation 44.620 45.060 State Police/ Forestry 45.080 45.860 Police/ Local Government/ Highways 45.900 46.040 Police/ Emergency 46.060 46.500 Fire 46.520 46.580 Local Government 46.610 46.970 Cordless Phone bases 47.020 47.400 Highway maintenance 47.440 47.680 Industry/ Emergency 47.700 49.580 Industry 49.670 49.900 Cordless Phones Handsets |
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| Since the autumn of 1998 it has been possible to hear a variety of signals from the USA at Low VHF from here in Europe. The reason for this has been our current position in the 11-year sunspot cycle, which governs reception at these frequencies. There is some debate as to when the peak of the current cycle actually occurred and there is some suggestion that in the last months a second solar peak has taken place. So, reception conditions should be good for some time to come. The reception of these and other world-wide signals is via the atmospheres F2 layer, and in the Northern Hemisphere the time to have a listen is late September until April. For the USA check 30- 50 MHz in NFM, steps of 20 kilohertz. In mid winter American traffic can be heard from around 1pm until about an hour after sundown. After sunset the higher frequencies disappear first while lower ones like the Fire comms at 33 MHz can hang on for an hour or two. The above bandplan will give you an idea of where to look and what you are likely to hear there, and the fact that 99% of these signals are in English makes identification of these signals a real possibility. Here are a few tips for working out the source of that amazing signal you just heard! I.D Most American public services will use an allocated ID usually heard at the end of a transmission. Keep your ears open, or better still attach a tape or mini disc recorder to your scanner- that way you won’t miss much. Incidentally it’s amazing how often you can mishear a fast spoken ID so it’s good to have something to refer back to. Once you have a full or partial ID you can check it out at the Federal Communications Commission online database. You can perform a variety of searches there as well as actually just look up an ID. See the below link. References to locations and roads. US Fire and Police communications will often refer to town or county names and road or highway numbers. If you for instance hear a reference to an Interstate followed by say the last numbers of an ID you will be able to go to the FCC database knowing which states the signal may have come from, this plus the partial ID will make a positive identification much easier. The more info you can glean from a transmission, the more likely you are to work out what it was and where it came from. There is a link at the bottom of this page, which gives details of the location of all of Americas Interstate Highways. There is also a text file with a full list of American county names. You will often hear these referred to as many American Fire and Police departments are organised on a county basis and often use the county name in dispatches. A good road atlas of the USA is an absolutely invaluable tool in working out what you are listening to. Soft cover versions printed by the AA in Britain are both cheap and easily found on the high street. In the past I have listened to Firetrucks speeding to accidents on Interstates and have been able to track their progress due to their references to mile markers intersections and turnoffs!. A Police chase is even more exciting- One of the best I have heard was a firefight and car chase involving State Troopers on Tryon Road in Raleigh, North Carolina! (Beats listening to Irish taxis getting lost anyday!). Time-checks Public service transmissions from the USA often end with time-checks, familiarise yourself with where the time zone boundaries lie. If you hear a Highway Patrol dispatcher give a time UTC minus 5 hours it is therefore more likely to be North Carolina than say Missouri. See the link below. Finally check out my loggings page here to give you an idea of what is to be heard right now. Happy listening!. |
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| US Fire 33.42-34mhz in 20 kc steps NFM |
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| Useful Links |