Langwellen

Langwellen, literally long waves, is a term used in radio engineering and physics to describe electromagnetic waves with longer wavelengths than those of most common broadcasting bands. In radio terminology, long waves generally refer to the low-frequency part of the spectrum, roughly from 30 kHz to 300 kHz, which corresponds to wavelengths of about 1 to 10 kilometers.

Propagation and characteristics. Longwave radio signals propagate primarily as ground waves, traveling along the surface of the Earth and bending around obstacles that would block higher-frequency signals. This mode of propagation allows long-distance reception even beyond the line of sight, especially over seawater where ground conductivity is high. At the same time, longwaves can be less reliable for high‑capacity communications due to their low data rates and greater susceptibility to man-made and natural noise. In some conditions, skywave propagation can contribute at the lower end of the band, but it is less dominant than for higher frequencies.

Applications and usage. Historically, longwave communications have been used for nationwide broadcasting and time-signal transmissions in various countries, as well as for maritime and special-purpose communications. In many regions, longwave broadcasting has declined in favor of medium wave, shortwave, and digital services, but some broadcasters and time-signal stations still operate on longwave frequencies.

Relation to other bands. Langwellen are distinct from medium waves and shortwaves, which occupy higher frequencies and rely more on ionospheric reflection for long-distance reach. The term emphasizes the relationship between wavelength, propagation behavior, and the practical constraints of transmitting equipment at these frequencies.