Medelfrekvensen

Medelfrekvensen, or medium frequency, refers to a range of radio frequencies used for various communication purposes. This band typically spans from 3 to 30 megahertz (MHz). It is a crucial part of the radio spectrum, falling between the lower frequency shortwave bands and the higher frequency very high frequency (VHF) bands.

One of the key characteristics of medelfrekvensen is its ability to propagate over long distances. This is primarily due to its capacity to reflect off the ionosphere, a layer of charged particles in the Earth's upper atmosphere. This reflection allows radio waves to travel beyond the horizon, enabling both shortwave broadcasting to a wide audience and long-distance communication, particularly during daylight hours when the ionosphere is more conducive to reflection.

Historically, medelfrekvensen has been vital for international broadcasting, maritime communication, and amateur radio. Many well-known shortwave radio stations utilize these frequencies to transmit programs across continents. Ships at sea also rely on medelfrekvensen for communication with shore stations and other vessels, especially in areas where satellite communication may not be available or cost-effective. Amateur radio operators find this frequency range particularly interesting for its potential for DXing, or contacting distant radio stations. The propagation characteristics can vary significantly depending on the time of day, season, and solar activity, adding a dynamic element to its use.