Before assembly of underwater connectors, make sure all connector 0-rings are 

 in place and in satisfactory condition. Coating these 0-rings with grease also is 

 recommended. Otherwise, manufacturer instructions should be followed. 



The towcable armor should be inspected during each retrieval and during launch- 

 ing, particularly at the remote sensor locations, for signs of abrasion and for 

 broken wires. The remote sensors will induce a degree of stress concentration in 

 the towcable and increase susceptibility to local fatigue failure. If more than one 

 or two armor strands are broken at a particular location, the cable should be cutoff 

 at this location and reterminated. To decrease the likelihood of cable fatigue, the 

 remote sensors shoud be shifted to slightly different locations each time they are 

 secured to the towcable. If experience with the system indicates that the cable 

 fatigue at the remote sensor location is a problem, a rubber liner in the brass clamp 

 may reduce this tendency. Otherwise, alternate methods of securing the sensors will 

 have to be examined. 



The towcable will begin to show red-colored corrosion as the galvenizing is 

 abraded away. Washing the cable with freshwater during retrieval will help prolong 

 the life. With proper care, the towcable probably can be used for about 500 hours 

 of towing. If the towcable is put into storage for an extended period, it should 

 be thoroughly cleaned of any saltwater deposits. A coating of grease may also help. 

 Recently, Rochester Corporation has begun to manufacture this cable design using 

 Nitronics 50, a material which apparently is not susceptible to corrosion. As a 

 further measure to prolong cable life, the minimum cable bend radius should never 

 be less than 150 mm (12 in.). 



Some ribbon-fairing normally will be stripped from the cable by sheaves, etc. 

 during streaming and retrieval. Approximately 50 percent of the fairing can be lost 

 before performance of the fairing is appreciably degraded. 



CONTROL ELECTRONICS OPERATION 



To operate the control electronics, preset the following switches and control 

 on the shipboard instrument package prior to connection to the ac line. 



Control Unit 



1. ON-OFF SWITCH - to OFF position 



2. RANGE SWITCH - to position 



3. RANGE VERNIER - to 0050 



58 



