 "Knickebein" was soon superseded by "X-Gerät" and "Y-Gerät" directional beams, which in turn were eventually jammed by 80 Wing in the ongoing Battle of the Beams.In early November intelligence pointed to a major operation being planned by the "Luftwaffe" against the Midlands (Operation "Mondscheinsonate" (Moonlight Sonata).The operation orders to the "X-Gerät" stations on 14 November were intercepted but could not be deciphered by Bletchley Park in time, although 80 Wing's aircraft detected the "X-Gerät" radio frequencies.