 It was built using the electronics being developed for the Airborne Interception radar systems, which worked on the 1.5 m band.This high-frequency, for the era, allowed it to use smaller antennas that could be swung back and forth to look for returns, in contrast to the enormous fixed antennas of the 6.7 m wavelength Chain Home system.When the war opened, the "Luftwaffe" began mine-laying missions where the bomber aircraft would fly almost all of their mission flying at low altitude.