Abstract :
The Naval Research Laboratory has developed a cable television system for use with the deep ocean search equipment used to locate the lost submarines THRESHER, SCORPION, ALVIN, and EURYDICE. The video equipment differs from most previous long-cable (6000 m.) systems used in the deep ocean in that the television signals are heterodyned into the 0.5-4. 25 MHz band in order to eliminate interference with existing search-system telemetry without Incurring the very large cable losses encountered at higher frequencies. The resulting heterodyne equipment is unusual because the 3.75 MHz band width is of the same order of magnitude as the 4.25 MHz carrier frequency, rather than being much smaller as is the usual case. This unusual feature causes a number of problems which limit performance of the television system. The equipment was de signed to minimize the determental effects of these problems. The television system was integrated into the search equipment and sucessfully field tested aboard the USNS MIZAR in the fall of 1.974.
