Geneva Frequency Plan of 1975
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The Geneva Frequency Plan of 1975 (GE75) is the internationally agreed frequency plan which was drawn up to implement the provisions of the Final Acts of the Regional Administrative LF/MF Broadcasting Conference (Regions 1 and 3) held in Geneva, Switzerland, in 1975. It covers radio broadcasting in the long and medium wave bands outside the Americas (separate agreements being in place for North and South America).
The plan was drawn up under the auspices of the World Administrative Radio Conference (WARC) of the International Telecommunication Union (ITU) with the assistance of the European Broadcasting Union (EBU/UER)
The Geneva plan replaced the 1948 Copenhagen plan. It became necessary because of the large number of broadcasting stations in these frequency ranges leading to ever more mutual interference. That Geneva wave plan entered into force on 23 November 1978 and although its intended lifespan was only until 1989 it is still valid (with small modification by mutual coordination between countries) today.
Most existing European radio stations were required to change their broadcasting frequencies following implementation of plan . In most cases the changes were slight (only one or two kilohertz) but were more drastic in some cases, particularly in the United Kingdom. However the increased number of radio services and reduction (in most cases) of interference to radio signals (particularly at nighttime) was considered by broadcasters to be worth the initial inconvenience.
As a result of the plan most medium wave (and later longwave) stations outside North and South America operate on exact multiples of 9 kHz which helps reduce heterodyne interference.
[edit] Predecessors to the GE75 Plan
- Geneva 1925 (effective 14 Nov 1926) 10 kHz spacings on MW;
- Brussels 1928 (effective 13 Jan 1929) 9 kHz spacings on MW (10 kHz above 1000 kHz);
- Prague 1929 [1](effective 30 June 1929) "European Radio-electric Conference of Prague 1929" 9 kHz spacings on MW (10 kHz above 1400 kHz);
- Madrid/Lucerne 1932 [2] (effective 15 Jan 1934) "Lucerne Convention European Wavelength Plan" Mostly 9 kHz spacings but not harmonic multiples;
- Montreaux 1939 (was to be effective 1940 but never implemented due to World War II);
- Copenhagen 1948 [3](effective 15 Mar 1950) "European LW/MW Conference Copenhagen 1948 (European broadcasting convention)" Mostly 9 kHz (8KHz above 1529 kHz 7, 8 and 9 kHz on LW) spacings but not harmonic multiples—offset 1 kHz on MW and (generally) 2 kHz on LW.
