Today, it is namely the Alexanderson Day, in memory of Ernst Alexanderson who invented the alternator (below). It is celebrated by actually broadcasting from the only electro-mechanical alternator of the kind. Radio amateurs around the world don't miss this opportunity, and at least some reports about received signals reached me during the visit (via internets).
I'm not gonna go into details about the Grimeton VLF Transmitter. Wikipedia already did. But I can provide some pictures, a video and some soundscapes!
When you enter the area, these fine antennae are in your sight.
The Alexanderson alternator. Steampunk!
Man in uniform fine-tuning the broadcast. The noise is alarming!
Action shot of the actual broadcast.
One more picture of the alternator. All pictures are here.
I brought my sound recorder as well, so, well... Download and do whatever, if you feel like it. (no copyright BS, but you need to use port 9002).