Grimeton Radio Station

Listen for a moment. Out here in the Halland countryside, east of Varberg, the loudest sounds are usually the wind and the birds. The fields roll away in soft greens and browns. Then you lift your eyes, and a line of steel towers marches across the farmland. Each one carries wide arms at the top, like a giant telegraph pole drawn by a child. This is Grimeton Radio Station — and those towers once carried messages across the Atlantic Ocean.

To understand why this place exists, picture the world just after the First World War. Telegraph messages between Europe and America travelled mostly through undersea cables. Those cables were expensive, slow to repair, and often controlled by other countries. Sweden wanted its own direct line to the United States. A new technology promised a way to do it — sending long-distance signals through the air, without any wire at all.

The station was built in the early 1920s and began its transatlantic service in the middle of that decade. Its partner station stood on Long Island, near New York. Messages went out as Morse code — short and long pulses — and operators on the far side wrote them down. For business people, journalists, and families with relatives who had emigrated to America, this was a fast new link to the other side of the ocean.

Now look again at the towers. There are six of them, each about 127 metres tall. They stand in a straight line, spaced far apart, and together they hold up the antenna — a set of wires that stretches for roughly two kilometres. The towers themselves do not send the signal. They are simply holders. The real work happens in those wires hanging between them, high above the grazing land.

Here is the first surprise. Grimeton does not use the kind of radio you know from a car or a kitchen. It works on very low frequency, often shortened to VLF. Its signal sits at 17.2 kilohertz. That is so low that, if it were sound instead of radio, a human ear could almost hear it as a high whistle. Waves this long follow the curve of the Earth, and they can even pass a little way into seawater.

Inside the transmitter hall is the heart of the station — the Alexanderson alternator. It was designed by Ernst Alexanderson, a Swedish-born engineer who made his career in the United States. Instead of glowing radio valves or modern electronics, this machine makes radio waves mechanically. A heavy steel rotor spins at very high speed, and that motion creates the signal. It is closer to a giant electric generator than to anything we would call a radio today.

And here is the second surprise. Machines like this were once the leading technology for long-distance radio. Within a few years, however, shortwave radio and electronic transmitters made them old-fashioned. Almost all of them were scrapped. The alternator at Grimeton is the last one in the world that still works. This is why the site was added to the UNESCO World Heritage List in 2004 — as a rare, complete record of early wireless communication.

The buildings deserve a careful look too. The architecture is calm and classical, with clean lines and well-ordered windows. It feels more like a public institution than a factory. That choice says something about how people saw radio at the time. It was not just machinery. It was national infrastructure, a source of pride, and the designers gave it a dignified home in the middle of the fields.

The station did not stop working when transatlantic telegraphy moved on. Because very low frequency waves can reach a little way under the sea, the signal was useful for sending messages to submarines. For many years, the site served the Swedish navy in this role. So the same fields that once sent business telegrams to New York later helped keep contact with vessels hidden under the waves.

Today, the old alternator still comes to life on special occasions. The best known is Alexanderson Day, held each summer, and there is often a broadcast around Christmas as well. On these days, the station uses its historic call sign, SAQ. Amateur radio fans across Europe and beyond tune in, listen for the Morse code, and send reports back to say they heard it. A message from the 1920s machine still reaches people around the world.

If you are here when the machine runs, notice the sound and the feeling of the hall. The rotor turns with a deep, steady hum. The air feels warm from the equipment. Engineers watch dials and switches that look like props from an old film. Even on a quiet day, the size of the machinery tells the story. Everything is heavy, solid, and built to run for decades.

As you walk around the grounds, think about the scale of the whole system. The power came from this building. The signal travelled up into the long antenna. From there, it spread out over the land, over the sea, and toward a listener thousands of kilometres away. All of this happened before television, before the internet, and before most homes had a telephone.

The landscape around you has changed very little. Cows and sheep still graze beneath the wires. Farm roads cross the fields between the towers. That contrast is part of the charm of Grimeton — a peaceful rural scene with one of the great engineering projects of its era running straight through it. Stand near the base of a tower and look up. The crossarm feels very far away against the sky.

Before you leave, pause and let the place settle. Listen again to the wind moving through the steel and the wires. A century ago, people stood in these same fields and knew that words were flying from here to America in invisible waves. As you walk back toward the road, count the towers one more time. Six quiet giants in a row — still standing, still ready to speak.