The Alexanderson Day (named after the inventor Ernst Fredrik Werner Alexanderson) is the great day of the open house at the VLF transmitter Grimeton. On Alexanderson Day the only workable rotating machine transmitter in the world is used to transmit short Morse messages on 17.2 kHz, which should be easily receivable in all of Europe. A modern and very convenient way for their reception is a PC with a coil connected to the soundcard input and FFT-analysis software.
Alexanderson Day for 2005 is planned to be July 3, 2005. See []