Abstract :
The simplification in construction and operation of the personal radio beacon which a pulsed system gives justifies the need for a special receiver in the search aircraft or vessel. A double pulse is used to (1) give maximum system sensitivity, (2) permit discrimination between beacons, (3) facilitate synchronization. Speech may be transmitted from the beacon by pulse frequency modulation. Reception from the search vessel is by a super-regenerative circuit. The search equipment can detect beacon pulses at a range 90 statute miles at 10,000 ft.(145 km at 3,050 m). When mounted in a boat, double Yagi aerials are used giving a detection range of six miles (9.7 km).
