Longwave transmitter Allouis
The longwave transmitter Allouis went in service in 1939 as central longwave transmitter of France. It is located in the village of Allouis.
Until its destruction in 1944 by German Forces it used an aerial with four masts and a transmitter with 500 kilowatts. On October 19, 1952 a new longwave transmitter with a power of 250 kilowatts went into service. It used as aerial a special cage aerial, which were mounted on a 308 metre high guyed mast. These reusens were fed near the basement of the mast and were grounded at the other end, which was 915 metres away from the mast. In 1957 the transmission power was enlarged to 600 kilowatts, in 1974 to 1000 kilowatts and in 1981 to 2000 kilowatts. In spite of this, transmission power is reduced to 1000 kilowatts at nighttime.
In 1974 the aerial was renewed. The reusen aerials were removed and the mast was enhighed to 350 metres. There was also a construction of a second mast of the same hight. Since 1977 the transmitter in Allouis is not only used for transmission of the radio programme France Inter, but also for the transmission of time signals, according to the AMDS-mode.
The carrier frequency of the transmitter is derived from an atomic clock in the transmitter building. It is therefore a standard frequency.