Långvågsband

Långvågsband, also known as the longwave band, refers to a specific range of radio frequencies typically spanning from 300 kHz to 3000 kHz (0.3 MHz to 3 MHz). This band is part of the very low frequency (VLF) and low frequency (LF) spectrum, though it primarily encompasses the LF portion. In international radio regulations, the designation for this band can vary slightly, but it generally sits between the medium wave (MW) and short wave (SW) bands.

Historically, longwave broadcasting was widely used for AM radio transmissions due to its ability to travel long distances, especially at night. The propagation characteristics of longwaves allow them to follow the curvature of the Earth (ground wave) and also to be reflected by the ionosphere, enabling reception over vast areas. This made it ideal for national and international broadcasting services before the advent of FM and digital radio technologies.

Today, while its use for general entertainment broadcasting has diminished in many parts of the world, the longwave band still plays a crucial role in certain applications. These include time signal broadcasts, navigation systems like LORAN (though largely superseded), and specialized communication services. The inherent stability and long-range capability of the longwave spectrum continue to make it valuable for these specific, often critical, functions. Interference can be an issue due to its susceptibility to atmospheric noise and man-made electrical disturbances.