Long wave transmitter
The long wave transmitter at Roumoules, which was inaugurated in 1974, works on 216 kHz (until 1988: 218 kHz) with a transmission power of 1400 kilowatts (until 1976 2000 kW). It consists of two 1000 kW transmitters switched in parallel, which are however run with 700 kW output power. A third 1000 kW unit is available since 1983. Although this unit is only used as backup unit, it is possible to switch all three units in parallel, which would allow an operation with a transmission power of 3000 kW.
As aerial the long wave transmitter uses a directional aerial with a maximum pointing toward Northwest (azimuth: 309°). It consists of three 300 metre high guyed masts, which are insulated against ground and ground-fed. As backup for this antenna a 330 metre high guyed, ground-fed lattice steel mast radiator is available on the site. This mast allows of course only an omnidirectional radiation pattern.
The grounding system of the long wave transmitter is very large. The total length of all wires of the grounding system is 200 kilometres. It covers an area of 150 hectares. Because the area around the mast is used for agriculture, the ground wires are laid in a depth of 80 centimetres.
Medium wave transmitter
In 1987 a switchable directional antenna consisting of five ground-fed guyed masts was built nearby for the 1467 kHz medium wave frequency, which was previously transmitted from a transmitter at La Madonne. This antenna allows a switchable directional radiation in the following directions:
The action for changing the direction lasts only 5 seconds. Remarkable is, that there are no helix buildings at the basements of the masts used for medium wave transmission and that the devices for tuning the masts to the transmission line, which is as that of the long wave transmitter built as overhead line, are placed in the open air.
The medium wave Roumoules transmitter has an output power of 1000 kW. It is also used for transmitting the religious program of Trans World Radio. In opposite to the long wave transmitter, which can be received at day- and night time well in Southern France, Northern Italy, Switzerland and Southern Germany, this transmitter cannot be normally received well in areas more than 100 kilometres away from Roumoules. However at nighttime its waves may have because of its excellent skywave propagation at least the same range as those of the long wave transmitter.
Power supply
Transmitter Roumoules has a great power consumption. This is covered by 2 transformers each capable of 5000 kW. The power is delivered by a 150 kV and a 220 kV powerline. This way of power supply is overdimensioned (it would mean, that each community with 5000 people would have its own substation to the 150kV-grid), but it ensures a very safe power supply. Nevertheless there is a generating set of 3300 horse power (2460 kW) on the site and a possibility to supply the station of the local 20kV grid.
power distribution transformers
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