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.TV Frequency Table csgnetwork.com
Channel Frequency range7174–180 MHz8180–186 MHz9186–192 MHz10192–198 MHz11198–204 MHz12204–210 MHz13210–216 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 rangeE5174–181 MHzE6181–188 MHzE7188–195 MHzE8195–202 MHzE9202–209 MHzE10209–216 MHzE11216–223 MHzE12223–230 MHz
The Irish (8 MHz) system is shown below.
Channel Frequency rangeD174–182 MHzE182–190 MHzF190–198 MHzG198–206 MHzH206–214 MHzi214-222 MHzJ222-230 MHz
Oceania Australia has allocated 8 channels in Band III for digital television, each with 7 MHz bandwidth.
Channel Frequency range6174–181 MHz7181–188 MHz8188–195 MHz9195–202 MHz9A202–209 MHz10209–216 MHz11216–223 MHz12223–230 MHz
Russia and other former members of OIRT
Russian analog television is transmitted using System D with 8 MHz channel bandwidth.
Channel Frequency range6174–182 MHz7182–190 MHz8190–198 MHz9198–206 MHz10206–214 MHz11214-222 MHz12222-230 MHz
Radio
The band came into use for radio broadcasting at the turn of the 21st century and is used for DAB (Digital Audio Broadcasting).
It is subdivided into a number of frequency blocks used for multiplexes:
Block Centre Frequency5A174.928 MHz5B176.640 MHz5C178.352 MHz5D180.064 MHz6A181.936 MHz6B183.648 MHz6C185.360 MHz6D187.072 MHz7A188.928 MHz7B190.640 MHz7C192.352 MHz7D194.064 MHz8A195.936 MHz8B197.648 MHz8C199.360 MHz8D201.072 MHz9A202.928 MHz9B204.640 MHz9C206.352 MHz9D208.064 MHz10A209.936 MHz10B211.648 MHz10C213.360 MHz10D215.072 MHz10N210.096 MHz11A216.928 MHz11B218.640 MHz11C220.352 MHz11D222.064 MHz11N217.088 MHz12A223.936 MHz12B225.648 MHz12C227.360 MHz12D229.072 MHz12N224.096 MHz13A230.784 MHz13B232.496 MHz13C234.208 MHz13D235.776 MHz13E237.488 MHz13F239.200 MHz
Grayed frequencies aren't used for DAB. Furthermore, some countries like Germany don't use channel 13's frequencies to prevent interference with aviation frequencies.
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.FCC TV Query: US DTV construction permit listings for VHF Band I (ch 2–6) and III (ch 7–13)
Amateur (Ham) Radio has a small allocation of the band, known as the 1.25meter band, from 219 to 220MHz and 222.0 to 225.0 MHz for communications.
References