There are a number of VHF FM broadcast bands in use around the globe, and within these channels or frequencies are generally organised to provide the minimum of interference, while using the spectrum in an efficient manner.
Each country allocates the channels and frequencies in a slightly different manner, although within the overall ITU guidelines. As a result there is a large degree of conformity across the globe for the bands and channels used, although there are some local variations
Main VHF FM bands
There are a number of band allocations used around the globe:
- 87.5 - 108.0 MHz: : This is the "standard" VHF FM band - the one that is most widely used around the globe.
- 76.0 - 90 MHz: : This VHF FM band is used in Japan.
- 65.8 - 74.0 MHz: : This VHF FM band is known as the OIRT band. It was used in Eastern Europe, although few countries (Russia, Ukraine, and some other still use. However there is a move to using the more standard 87.5 - 108 MHz band.
VHF FM broadcast band plan for UK
In the UK, the VHF FM broadcast band is split between the various forms of broadcasting supplied by the national broadcaster, the BBC, which is funded by a licence fee, and independent radio which is funded on a commercial basis, chiefly by advertising.
|UK VHF FM Broadcasting Band Plan|
|87.5 - 88.0||Restricted Service Licences|
|88.0 - 90.2||BBC Radio 2|
|90.2 - 92.4||BBC Radio 3|
|92.4 - 94.6||BBC Radio 4|
|94.6 - 96.1||BBC local radio|
|96.1 - 97.6||Independent local radio|
|97.6 - 99.8||BBC Radio 1|
|99.8 - 102.0||Independent national radio|
|102.0 - 103.5||Independent local radio|
|103.5 - 104.9||BBC local radio|
|104.9 - 108.0||Independent local radio|
It can be seen that specific BBC national radio stations are allocated bands within the overall band-plan. The requirement for this amount of spectrum enables the whole country to be covered without undue levels of interference because stations are not sufficiently spaced in distance.
VHF FM broadcast channels & frequency plans for North America
In North America, the VHF FM band plans and frequencies are allocated in a slightly different way to other areas.
The VHF FM channels range from 87.8 to 108.0 MHz, proving an overall bandwidth of 20.2 MHz.
The stations are assumed to have a bandwidth of 200 kHz, and they are allocated centre frequencies (dial frequencies) with odd numbers for the figure after the decimal point, i.e. 87.9, 88.1 . etc.. This provides a total of 101 channels. These are given FCC designations of 200 for 87.9 through to 300 for a frequency of 107.9.
The upper 80 channels, VHF FM channels 221 to 300 on frequencies between 92 and 108 MHz are used for commercial broadcasting. The lower 21 channels, i.e. those between channel numbers 200 and 221 are reserved for non-commercial educational broadcasts. Note that Canada and Mexico, countries that directly border onto the USA do not observe this reservation
Japanese VHF FM frequency band
The VHF FM band that is sued within Japanese extends from 76 to 90 MHz because the 90 to 108 MHz band is used for analogue VHF television - three channels each 6 MHz wide.
The Japanese VHF FM band is only 14 MHz wide and this limits the number of stations that can be accommodated, and as a result, many stations use AM.
Australian VHF FM band
Australia has taken on board the standard VHF FM band allocation of 87.5 - 108 MHz. Although VHF FM broadcasting opened in 1947, it did not gain sufficient market acceptance inth e early days and as a result the system was shut in 1961. It then re-opened in 1975 as VHF television closed.
Now much broadcasting takes place on VHF FM, with talk stations adopting he AM frequencies.OIRT VHF FM band
The OIRT VHF FM band was used within much of the old Soviet block where they were members of the International Radio and television Organisation in Eastern Europe - OIRT. These countries included the USSR (now Russia) as well as most Eastern European countries, although not Eastern Germany and Yugoslavia as it was then.
The OIRT VHF FM band covers 65.8 - 74 MHz. It has advantages that the coverage area provided by the OIRT band is greater than that provided by the more widely used 87.5 - 108 MHz band.
As a result of the band being relatively small, and the lower requirement for high fidelity, the channels are only 10 kHz wide. The narrower bandwidth also helps with selective propagation issues that are more prevalent at these frequencies as well.
Most countries that used the OIRT band are now moving to the more standard 87.5 - 108 MHz allocation.