…trying out the WordPress iPhone app.
After being with Tumblr for 4 months, I’m back to WordPress.
3.0 is pretty awesome!
The American Association of Railroads has assigned channel numbers to each of 96 radio frequencies in the 160-161 MegaHertz bands. These frequencies are used in the United States and Canada. Channels 7-96 are used in the U.S. for railroad operations. Channels 2-6 are used in Canada for rail operations only. In the U.S. channels 3-6 are used by railroads for truck operations.
The following table converts from AAR channel number to the appropriate radio frequency (MHz).
Note that these frequencies are not the only frequencies used by railroads. Some railroads also use frequencies in the 4xx.xxx MegaHertz band, particularly around 45x.xxx, 46x.xxx, and 47x.xxx.
Most official railroad radios that synthesize the frequencies have a window that shows the AAR channel number for transmitting and the AAR channel number for receiving. For example, Amtrak’s primary Road frequency in the Northeast Corridor is 160.920 MHz, Channel 54. The window on the railroad radio would show 5454 (transmit on AAR channel 54 and receive on AAR channel 54).
Railroads also use some frequencies to transmit end of train telemetry. Some EOT devices, for example, transmit the train’s brake pressure to the closest tenth of a pound and whether the EOT is moving or not every 40 seconds or whenever there is a change. AAR has allocated 457.9375 MHz and 452.9375 for EOT telemetry with the latter used at the head end to transmit control signals. Most railroads use these frequencies. However, Norfolk Southern uses 161.115 MHz (AAR Channel 67) for EOT devices.
Since EOT devices transmit at two watts, the transmission will travel about 3 to 5 miles. Thus, by setting your scanner to scan these EOT frequencies, you get a warning whenever a train approaches. The problem with this strategy, of course, is that as soon as your scanner picks up anything on 457.9375 or 452.9375, it will lock on that channel. Thus, this strategy works best if your scanner makes it easy to change the channels that are scanned so that you can stop scanning 457.9375/452.9375 when you know a train is close.
The United States, Canada and Bermuda operate their government weather radio stations on the same band.
The original numbering was from the order in which the frequencies were assigned, with 162.55 at first the only frequency, then 162.4 and 162.475 added later to prevent RF interference. The others mainly came into use in the 1990s in less-populated rural, areas and as fill-in broadcast translators relaying an existing station into remote or mountainous areas.
Canadian broadcasts are also transmitted on travelers’ information stations on FM and AM, especially near national parks. Bermuda has only one station dedicated purely for weather, on 162.55 MHz from Hamilton, now operated by the Bermuda Weather Service. It has a second station, however, for marine conditions and forecasts, ZBR, at 162.400 MHz.
All stations transmit a 1050 Hz tone immediately before issuing a watch or warning, and this serves to activate the alert feature on many older radios. Except for Bermuda, all U.S. and later Canadian stations transmit WRSAME codes that allow more advanced receivers to only listen for certain warnings that carry a specific code for the local area, and often to alarm only for serious warnings (for example, a flood warning could be ignored by a person living on a mountain, while a tornado warning is an immediate emergency in all cases).
|Frequency||Old name||New name|
|162.400 MHz||WX 2||WX 1|
|162.425 MHz||WX 4||WX 2|
|162.450 MHz||WX 5||WX 3|
|162.475 MHz||WX 3||WX 4|
|162.500 MHz||WX 6||WX 5|
|162.525 MHz||WX 7||WX 6|
|162.550 MHz||WX 1||WX 7|
Link: Signal – iPhone app
Signal is a utility created by iPhone Dev Team member planetbeing that displays information about the cell tower your iPhone is connected to as well as neighboring cells. It detects and maps the location of all nearby cell towers so that the user can easily get a good idea of their cellular coverage or where to go to get the best cellphone reception. Combined with the free iPhone carrier unlock that planetbeing has helped create, a user can swap SIMs and determine which carrier is best for him or her based on cellular coverage. In addition the map, other useful technical data is displayed including RSCP (signal strength) in dBm and Ec/N0 (signal quality) to all neighbors, the PSC of the cells, as well as the frequency each cell is broadcasting in.
Signal is exclusively available from the Cydia Store on jailbroken iPhone 3G, iPhone 3GS and iPhone 4.