Energy pulse

In 1941, a Dalek saucer had a "big dish" fitted on its side transmitting an energy pulse which forced all the lights in London to switch on, leaving the city vulnerable to German attack. Modified spitfires were sent to stop the signal and, after the Eleventh Doctor temporarily deactivated the Daleks' shields, Danny Boy destroyed the dish and the pulse with it. (TV: Victory of the Daleks)