Band III
From Wikipedia, the free encyclopedia
Band III is the name of a radio frequency range within the very high frequency part of the electromagnetic spectrum.
Band III ranges from 174 to 230 MHz, and it is primarily used for radio and television broadcasting.
Contents |
[edit] Television
[edit] North America
The band is subdivided into seven channels for television broadcasting, each occupying 6 MHz.
| Channel | Frequency Range |
|---|---|
| 7 | 174-180 MHz |
| 8 | 180-186 MHz |
| 9 | 186-192 MHz |
| 10 | 192-198 MHz |
| 11 | 198-204 MHz |
| 12 | 204-210 MHz |
| 13 | 210-216 MHz |
[edit] Europe
European Band III allocations vary from country to country, with channel widths of 7 or 8MHz. The standard channel allocations for most of Europe are 7 MHz wide and are as follows:
| Channel | Frequency Range |
|---|---|
| E5 | 174-181 MHz |
| E6 | 181-188 MHz |
| E7 | 188-195 MHz |
| E8 | 195-202 MHz |
| E9 | 202-209 MHz |
| E10 | 209-216 MHz |
| E11 | 216-223 MHz |
| E12 | 223-230 MHz |
The Irish system is shown below.
| Channel | Frequency Range |
|---|---|
| D | 174-182 MHz |
| E | 182-190 MHz |
| F | 190-198 MHz |
| G | 198-206 MHz |
| H | 206-214 MHz |
| i | 214-222 MHz |
| J | 222-230 MHz |
[edit] Radio
The band has only come into use for radio broadcasting within the last decade, and is used for Digital Audio Broadcasting. It is subdivided into a number of frequency blocks
| Block | Centre Frequency |
|---|---|
| 5A | 174.928 MHz |
| 5B | 176.640 MHz |
| 5C | 178.352 MHz |
| 5D | 180.064 MHz |
| 6A | 181.936 MHz |
| 6B | 183.648 MHz |
| 6C | 185.360 MHz |
| 6D | 187.072 MHz |
| 7A | 188.928 MHz |
| 7B | 190.640 MHz |
| 7C | 192.352 MHz |
| 7D | 194.064 MHz |
| 8A | 195.936 MHz |
| 8B | 197.648 MHz |
| 8C | 199.360 MHz |
| 8D | 201.072 MHz |
| 9A | 202.928 MHz |
| 9B | 204.640 MHz |
| 9C | 206.352 MHz |
| 9D | 208.064 MHz |
| 10A | 209.936 MHz |
| 10B | 211.648 MHz |
| 10C | 213.360 MHz |
| 10D | 215.072 MHz |
| 10N | 210.096 MHz |
| 11A | 216.928 MHz |
| 11B | 218.640 MHz |
| 11C | 220.352 MHz |
| 11D | 222.064 MHz |
| 11N | 217.088 MHz |
| 12A | 223.936 MHz |
| 12B | 225.648 MHz |
| 12C | 227.360 MHz |
| 12D | 229.072 MHz |
| 12N | 224.096 MHz |
| 13A | 230.784 MHz |
| 13B | 232.496 MHz |
| 13C | 234.208 MHz |
| 13D | 235.776 MHz |
| 13E | 237.488 MHz |
| 13F | 239.200 MHz |
[edit] Worldwide Usage
In the UK and part of Ireland, Band III was originally used for monochrome 405-line television. However this was discontinued by the mid 1980s. Some European countries (including Ireland) still use Band III for higher definition colour television, although this is now being gradually phased out. The use of the band for Digital Audio Broadcasting is now being widely adopted.
In North America, use of the band for colour television broadcasts is still widespread. Favourable propagation characteristics and reasonable power limits (up to 65kW for full-power digital television, versus 20kW or less on VHF Band I) have caused many US broadcasters to elect to move full-power ATSC stations to Band III VHF once NTSC US analog television is shut down in 2009.
