Portable beacon and radio telephone for aircraft guidance - has control circuit permitting automatic response to aircraft signal

摘要

A portable beacon used in aviation transmits automatically when a signal is received from an aircraft and therefore does not require an operator although radio telephone circuits are included. A portable beacon comprises a radio telephone (2) with handset (8) and comprising transmission (3), reception (4) and battery power supplies (5). A double pole switch (11) permits selective connexion of the antenna (10) and power supplies to either receiver or transmitter circuits and is also relay (13) operated from a switch (12) on the handset. Automatic control circuits (14) comprising a detector (15) and amplifier (16) with relay (17) and switch (18) driven from a separate power supply (19) permit an unmodulated signal to be transmitted when a brief signal is received from an aircraft (1).