Abstract: A transducer of acoustic energy through a water medium is fabricated in a manner which assures high reliability yet significantly reduces cost per unit by including modified conductive elements. A pair of flat conductors are interleaved sinuously through a ferroelectric stack in a mutually orthogonal relationship. The conductors are so interleaved as to electrically couple the elements of the ferroelectric stack in parallel in accordance with proven transducer design. At least one rod axially extends through the sandwiched ferroelectric elements and conductors to hold them in compression and to assure a reliable electrical connection for producing an integral hydroacoustically cooperating structure.

Abstract: Audio communications between divers or between a diver and a surface craft are made without unduly burdening the divers. Diver carried throat microphones pass vocal signals to a preamplifier-amplifier package. The package drives a transducer which projects amplified vocal signals that are capable of being heard by the other diver or feeds signals to a surface power supply pack and a speaker while a surface microphone enables communications from the surface to the divers. The divers don't carry any additional electronics instrumentations and, since there is no signal heterodyning, distortion is reduced.

Abstract: A hose-like hydrophone array is insensitive to ambient pressure variations hile retaining an acceptable performance capability. Ferroelectric cylinders mount rigid cylinders at opposite ends and are separated by elongate lengths of corrugated tubing. A dielectric oil fills the cylinders and lengths of corrugated tubing to make the array relatively insensitive to pressure variations. Since the dielectric oil is several times (five to 10) more compressible than the ambient water, the ferroelectric elements can more compliantly respond to a broader bandwidth of impinging or radiated acoustic energy. The radially rigid lengths of tubing hold a greater volume of the relatively compressible oil to permit this response.

Abstract: A transverse variable reluctance transducer of acoustic energy is configu to lend itself to being towed through the water while it radiates acoustic energy. Its elongate, cylindrical shape, which has an axial tunnel running its length, allows the flow of cooling water to prevent excessive heat from building up. The transducer's linear vibrator motor has its outer shell windings DC excited while the inner core or reciprocator has its windings AC excited. As the AC source is changed from one frequency range to another, responsive changes in the projected acoustic signal are radiated from suitably interconnected projection surfaces. In one configuration, one of the projection surfaces is in communication with the fluid flowing through the axial tunnel at one end of the transducer and another projection surface faces radially outwardly from the transducer's opposite end. Another configuration has both of these projection surfaces facing radially outwardly at opposite ends of the transducer.

Abstract: An improved line array transducer increases its effectiveness by ensuring a ore responsive trailing as it is towed through the water. An elongate sleeve contains a number of longitudinally spaced transducer elements which are responsive for the transmission or reception of acoustic energy. An interconnected, flexible bladder carried inside of a towing is coupled to the elongate sleeve. As the paravane leads the line array to its predetermined operational depth, the more compliant bladder yields to the pressure and is compressed. This compression of the bladder forces a contained gas into the interior of the elongate sleeve and the transducer's interiors to pressure compensate the array. By suitably choosing the materials and appropriately dimensioning the bladder, sleeve and transducer elements, an essentially neutrally buoyant line array is fabricated for deployment at the predetermined operational depth. Such an array trails responsively and does not generate excessive flow noise.