Abstract: This invention relates to a recoverable tethered platform system and to a tethered platform for use therewith. One end of a tether line is retained at a surface station while the majority of the line is initially mounted on a mandrel in the platform and is drawn from this mandrel as the platform descends. This permits more rapid descent of a platform since there are substantially no line drag forces to overcome during descent. During recovery, the line can be wrapped on a mandrel which is the same as the mandrel in the platform and this rewound mandrel may then be substituted for the empty mandrel in the platform for redeployment.

Abstract: A pressure transducer capable of measuring very high pressures with great accuracy. The transducer includes a metal structure enclosing a volume which forms a resonant cavity to provide the tuning element in a UHF oscillator. The resonant cavity provides an inductance and a variable capacitance, the capacitance being variable as a function of the pressure to be measured. A transistor oscillator is very loosely coupled to the tuned circuit and provides positive feedback to maintain the oscillation. Due to the loose coupling between the transistor and the tune circuit, changes in the input reactance of the oscillator circuit have very little affect on the frequency of the tuned circuit. The frequency varies as a function of the pressure and provides an indication thereof. Two embodiments of the transducer are described. A first embodiment includes two concentric tubes, a section at the center of the outer tube being reduced in diameter to form an annular gap to provide the variable capacitance.

Abstract: An acoustic transducer for use under water is constructed in such a manner that when out of the water the transducer element is substantially isolated from vibrations that otherwise would be coupled thereto from the mounting base on which it is mounted.