Abstract :
The paper surveys developments in radio aids to air/sea rescue since 1940, and discusses the medium frequency c.w. and v.h.f. radar beacons in general use during the second world war, together with later post-war developments of these equipments. The development of a v.h.f. c.w. dinghy beacon and the use of the airborne v.h.f. homer as the search equipment are discussed together with the change in operational requirements for a personal equipment with communication facilities. The author suggests that a crystal-controlled v.h.f. beacon having a low duty cycle may most readily satisfy international requirements for future radio aids to air/sea rescue. The desirability for a crash location beacon is also put forward.
