 | FM broadcast band: Encyclopedia II - FM broadcast band - OIRT bandplan
FM broadcast band - OIRT bandplan
The OIRT FM broadcast band covers 66 to 74 MHz. It was used in the Union of Soviet Socialist Republics and most of the other socialist countries of Eastern Europe, with the exception of East Germany and Yugoslavia, which always used the 87.5 to 108 MHz broadcast band in line with Western Europe.
Following the collapse of the communist governments in Eastern Europe, the 87.5 to 108 MHz band began to be adopted and is now in use in all countries. This was prompted by the expansion of broadcasting and the modernisation of existing transmission networks, using new or second-hand transmitters from western countries, together with a general desire for standardisation with the West.
Many countries have completely ceased broadcasting on the OIRT FM band, although declining use continues in others, mainly the former republics of the USSR. The future of broadcasting on the OIRT FM band is limited, due to the lack of new consumer receivers for that band.
Countries which still use the OIRT band include Russia[2], Belarus[3], Moldova[4] and Hungary[5]. However, Hungary plans to close down its remaining transmitters in 2006.
Unlike Western practice, OIRT FM frequencies are based on 10 kHz rather than 50 or 100 kHz multiples. This may have been to reduce co-channel interference caused by Sporadic E propagation and other atmospheric effects, which occur more often at these frequencies.
The 4 meters amateur radio allocation used in many European countries is entirely within the OIRT FM band. Operators on this band and the 6 metre (50 MHz) band use the presence of broadcast stations as an indication that there is an "opening" into Eastern Europe or Russia. This can be a mixed blessing because the 4 metre amateur allocation is only 0.5 MHz or less, and a single broadcast station causes considerable interference to a large part of the band.
It will be noted that the System D television channels R4 and R5 lie wholly or partly within the 87.5-108 MHz FM audio broadcast band. Countries which still use System D therefore have to consider the re-organisation of TV broadcasting in order to make full use of this band for audio broadcasting.
Other related archives107.9 MHz, 12-07, 1984, 2006, Americas, Articles to be expanded, Automobiles, Bandplans, Belarus, Broadcast engineering, CCIR, Cleanup from December 2005, Deviation, ERP, East Germany, Eastern Europe, FM, FM broadcasting, FM radio, HAAT, Hungary, ITU, Italy, Japan, MHz, Moldova, OIRT, Portable, Russia, Sporadic E propagation, System D, TV, U.S., Union of Soviet Socialist Republics, VHF, Yugoslavia, adjacent channels, amateur radio, audio, bandplan, broadcasting, capture effect, channel, class-D, frequency modulation, interference, kHz, modulation, radio, radio stations, receiver, selectivity, socialist, subcarrier, subcarriers, tuners
 Adapted from the Wikipedia article "OIRT bandplan", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki |
