What does "Knickebein" mean?

Short answer

Knickebein means "bent leg": the system's code name came from the shape of its antennas. The British called the beams Headache and built transmitters named "Aspirin" to mimic their signal. The RAF gave the X-Device its own code name, "Ruffian."

Published: November 4, 2026 · Updated: November 4, 2026 · Edited by Above Ten Thousand · Editorial policy

The Radio House in Fabianinkatu, Helsinki, 1941

"Crooked leg"

Knickebein means "crooked leg"; it was the shape of the antennas that gave the system that code name.

The British names

The RAF gave the beams the code name Headache. Transmitters, christened "Aspirin", were built to imitate the beam signal. The first jammers, called "Aspirins", were used against the Knickebein beams.

The X-Gerät and other code names

The RAF assigned the X-Device its own code name, "Ruffian". The X-Gerät worked at a much higher frequency than the Knickebein, around 60 MHz. The equivalent signal zone of the X-Gerät was only about 100 yards (91 m) wide at 200 miles (320 km) from the antenna. The experimental unit Kampfgruppe 100 was given the task of using its X-Gerät equipment to guide other aircraft to the target. The main antenna of the X-Gerät, called Weser, was installed just west of Cherbourg, in France. The system that used the Y-Gerät apparatus was known in the United Kingdom as "BENITO".