I am going to write a blog post about transmission antennae which will (hopefully) contain more information than you will ever need about the matter. This will make me look like so much of an expert that you will be in awe and scared to ask questions. With any luck, it won't look like I just learned all this stuff off Wikipedia...
Last Sunday the Days on the Claise Special Operations Bureau went to a village near Issoudun, in the Berry. In doing so we passed by some magnificent (if somewhat alien looking) radio transmitters.
These are the shortwave high power aerials used by Radio France Internationale for their shortwave broadcasts. These are receivable in most parts of the world, so at various times of the day RFI broadcasts are made in English, Kiswahili, Hausa, Spanish, Portuguese, Romanian, Russian, Persian, Chinese, Vietnamese and Cambodian. The funding for this comes directly from the budget of the French Minister of Foreign Affairs.
The antennae are known as ALLISS Antenna (from ALLouis + ISSoudun, the two sites in France they are located) and are very high power rotatable transmitters. There are 12 on the Issoudun site, and they can broadcast to the whole world from this one site. They are what I guess you could call fully configurable - not only do they rotate, but they can also change a number of other parameters with a staff of just three people. This means that if they want to focus broadcasts on just one part of the world they can do so within 15 minutes. Naturally they are a very expensive unit (between US$10million and US$15 million a piece). Even their own publicity states "Any competent and reasonable transmission planning person should look at all other shortwave transmission options before considering ALLISS."
in the foreground. In the background are the old style antennae.
p.s. yesterday was about 60°C warmer (+38°C) than it was 6 months ago (-20°C). In Simon maths that is a 10° increase of temperature per month. Luckily, the increse should stop any day now...