Radio wave
Radio waves were part of the electromagnetic spectrum which could only be detected with radios.
Pulsars emitted powerful beams of energy in the form of radio waves. (PROSE: Ghost Devices [+]Loading...["Ghost Devices (novel)"])
The Daleks could convert radio waves into light waves so that they could see anything that was happening around them, even millions of miles away. (COMIC: City of the Daleks [+]Loading...["City of the Daleks (comic story)"]) One Dalek Emperor could read thoughts through radio waves. (COMIC: The Brain Tappers [+]Loading...["The Brain Tappers (comic story)"])
In October 1963, Susan Foreman suffered from headaches caused by a hypersonic signal being transmitted over radio waves. (AUDIO: Hunters of Earth [+]Loading...["Hunters of Earth (audio story)"])
Professor Neob Frankel provided Kurt Wurlitzer with a rubber spacecraft which was designed to absorb radio waves. (COMIC: Operation Wurlitzer [+]Loading...["Operation Wurlitzer (comic story)"])
Star whales transmitted their song as radio waves. (AUDIO: The Song of Megaptera [+]Loading...["The Song of Megaptera (audio story)"])