The Allouis longwave transmitter first entered service, as France's central longwave transmitter, in 1939. It is located near the village of Allouis.
Prior to its destruction in 1944 by German forces, it used an aerial with four masts and a transmitter rated at 500 kilowatts.
On 19 October 1952 a new 250-kW transmitter came into service. This used a special cage aerial, mounted on a 308-metre high earthed mast. In 1957 the transmission power was increased to 600 kW, in 1974 to 1000 kW, and in 1981 to 2000 kW. Transmission power is reduced to 1000 kW during the hours of darkness.
In 1974 the aerial was renewed. The cage aerials were removed and the mast height was increased to 350 m. A second mast of the same height was constructed at the same time. Since 1977 the Allouis transmitter in Allouis has been used to transmit not only the France Inter radio channel, but also AMDS-mode time signals.
The carrier frequency of the transmitter is a standard frequency, being derived from an atomic clock in the transmitter building.

See also

Télé Distribution Française