Physics:Band III

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Short description: Range of radio frequencies

Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-band VHF, in contrast to Bands I and II.

Broadcast Television

North America

The band is subdivided into seven channels for television broadcasting, each occupying 6 MHz.[1]

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

Europe

European Band III allocations vary from country to country, with channel widths of 7 or 8 MHz.

The standard channel allocations for European countries that use System B with 7 MHz channel spacing 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 (8 MHz) 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

Oceania

Australia has allocated 8 channels in Band III for digital television, each with 7 MHz bandwidth.

Channel Frequency Range
6 174-181 MHz
7 181-188 MHz
8 188-195 MHz
9 195-202 MHz
9A 202-209 MHz
10 209-216 MHz
11 216-223 MHz
12 223-230 MHz

Russia and other former members of OIRT

Russian analog television is transmitted using System D with 8 MHz channel bandwidth.

Channel Frequency Range
6 174-182 MHz
7 182-190 MHz
8 190-198 MHz
9 198-206 MHz
10 206-214 MHz
11 214-222 MHz
12 222-230 MHz

Radio

The band came into use for radio broadcasting at the turn of the 21st century 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

Worldwide usage

Europe

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. Other European countries (including Ireland) continued to use Band III for analogue 625-line colour television.

Digital television in the DVB-T standard can be used in conjunction with VHF Band III and is used as such in some places. The use of sub-band 2 and sub-band 3 band for Digital Audio Broadcasting is now being widely adopted. Sub-band 1 is used for MPT-1327 trunked PMR radio, remote wireless microphones and PMSE links.

North America

In North America, use of the band for television broadcasts is still widespread. Favorable propagation characteristics and reasonable power limits (up to 65 kW for full-power digital television, versus 20 kW or less on VHF Band I) has meant that many US broadcasters elected to move their full-power ATSC stations from UHF frequencies to Band III VHF when all full-power NTSC analog television services in the US shut down in 2009.[2]

References