Pitkäaaltoasemas

Pitkäaaltoasema refers to a longwave radio transmission station. These stations broadcast on frequencies in the longwave band, typically between 148.5 and 283.5 kHz. Longwave radio waves have a greater range than shorter wavelengths, especially at night, and can travel over obstacles like hills and mountains more effectively due to their ability to diffract around the Earth's curvature. This makes them suitable for broadcasting over large geographical areas, including across national borders.

Historically, longwave broadcasting was a primary method for reaching wide audiences, particularly for national public service radio. The large antennas required for longwave transmission are a distinctive feature of these stations. While the development of other radio technologies and digital broadcasting has led to a decline in longwave's popularity in some regions, it remains in use for specific purposes, such as broadcasting official time signals, navigational aids, and for certain public broadcasting services where wide coverage is essential. In Finland, for example, Yleisradio previously operated longwave transmitters. The infrastructure for these stations is often substantial, involving significant antenna arrays and transmitter buildings.