Radio transceiver for locating casualties buried in snow - has pressure equalisation of interior of sealed casing to allow operation at high altitudes

摘要

The transceiver has a casing containing the electronic transceiver circuit, with a water-tight internal compartment (3) into which the loudspeaker (2) is fitted. A valve (9) operated manually via a push-button (12) allows the interior of the loudspeaker to communicate with the outside. Pref. the valve (9) has a valve flap (10) displaced longitudinally along a cylindrical housing (11) by depression of the push-button (12) attached to its top face, against a spring bias acting on its bottom face. The interior of the valve housing (11) communicates with the outside via an opening (13) in the casing (1) and with the loudspeaker compartment (3) via a passage extending through the wall of the valve housing (11). A toroidal seal (18) surrounds the push-button stem. The transceiver is operable at high altitudes.