Science Fair Project Encyclopedia
Broadcast band
The broadcast band is actually several chunks of the radio spectrum. In the U.S. the major broadcast bands are:
| Common Name | Frequencies | Cycles/Second | Modulation | Band | Notes |
| "FM" | 88 to 108 | MHz | Frequency Modulation (FM) | Very High Frequency (VHF) | Usually music, due to the clarity and high bandwidth of FM. Relatively short range. |
| "AM" | 535 to 1700 | kHz | Amplitude Modulation (AM) | High Frequency (HF) | Usually speech and news, where a lower bandwidth will suffice. Long range at night due to the ionosphere lowering in altitude. |
| "Shortwave" | 5.9 to 26.1 | MHz | Mostly FM, some AM and single-sideband (SSB) modes. | HF | Very long range through "skipping". Standard time frequencies can be heard here. |
| "Broadcast Television" | 54 to 88, 174 to 216, and 470 to 806 | MHz | vestigial sideband modulation for video and FM for audio | VHF and Ultra High Frequency (UHF) | Channels 2 through 6 are from 54 to 88 MHz. Channels 7 through 13 are from 174 to 216 MHz. Channels 14 through 69 are from 470 to 806 MHz. |
In Europe, North Africa and Asia, longwave radio frequencies between 153 and 281 kHz are used for domestic and international broadcasting.
See also
10-26-2009 08:16:03
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The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details