Asked by: Brian Newlove, CottinghamLike any antenna, a TV aerial is made of metal. Electromagnetic waves carrying television signals induce tiny electrical currents in the antenna. The television set amplifies the signal and selects the information that carries vision and sound. Engineers refer to TV aerials as 'yagi arrays'. The metal plate at the array's far end reflects the signal back down its length. The parallel rod-like structures that run along the length of the aerial are specially spaced to optimise signal strength.