As early as 1936, shortwave radio was tested on the Iron Ore Line, and in the late 1940s, experiments were conducted with radio link connections on the Stockholm–Boden route. However, the performance did not meet expectations, and the system was never fully developed.

Around the mid-1950s, American mobile and fixed radio stations were introduced for local use, such as for rail yard and locomotive radio communications.

In the early 1960s, advancements in transistor technology resulted in mobile stations becoming lighter, decreasing from five to two kilogrammes. The Autophon SE 18 A was a revolutionary station that entered the market during this time.

In 1962/63, Storno introduced a portable station, the CQP 500, weighing only 700 grammes.

Local radio systems at SJ

Rail yard radio is based on equipping personnel at rail yards with walkie-talkies connected to central equipment at the office of the rail yard management personnel. The central equipment is also connected to the telephone network.

Locomotive radio, installed in the locomotive, allows the driver and the shunting supervisor to communicate with each other.