Grimeton VLF transmitter

The Grimeton VLF transmitter is a radio station in Varberg fitted with six 127-meter towers that support extensive antenna wires for long-distance communication. The facility uses an Alexanderson alternator system with rotating magnets that generate signals at 17.2 kilohertz frequency.

Built between 1922 and 1924, the station became Sweden's sole telecommunication link to other countries during World War II, transmitting critical messages when other connections were cut off. The facility maintained this vital role until regular communications channels were restored after the war.

The station embodies early industrial design through its mechanical transmission methods, reflecting how people once imagined connecting distant parts of the world. Walking through the site, you see engineering craftsmanship from an era when radio was cutting-edge technology for society.

The site offers regular guided tours where you can see the working equipment and understand how the system operates in practice. Wear comfortable shoes, as visiting the towers and outdoor areas means walking across the grounds and climbing stairs.

The site houses the last working Alexanderson alternator on Earth, making it a living example of a technology no longer used anywhere else in the world. Every July during Alexanderson Day, visitors can watch the transmitter still sending Morse code signals across Europe, demonstrating machinery from over a century ago.