BENTHIC LABORATORY 



397 



Fig. 154. Comparison of the resolution of the two benthic laboratory TV 

 canaeras. The poor resolution of camera 2 was caused by either oilleak- 

 age into the optics or a faulty electromagnetic focus circuit 



Fig. 155. Benthic labora- 

 tory terminal block area 



valve was connected across the manifold would be accompanied by a reduction in the cavitation 

 noise. This reduction of sound was observed on the grip hydraulic circuit after a few seconds 

 delay, indicating the presence of a slow leak in the system. In future manipulations this fact 

 was taken into consideration by periodically re -energizing the grip solenoid whenever the grip 

 action was used. 



The next manipulation effort attempted was the use of the patch panel to check the perform- 

 ance of the amplitude -modulated communication links. In this operation camera 1 was used. 

 Its location between modules 8 and 9 gave an ideal vantage point for the operation on the patch- 

 panel board located in module 12. The manipulation was successfully carried out and involved 

 the transfer of both ends of the patch cord. One end was moved to the monitor jack on the up- 

 per half of the panel from its original position in the monitor jack on the lower half of the panel 

 (Fig. 156). The other end of the cord was then inserted into the desired jack in the panel (Fig. 

 157). The jack numbers were marginally readable in this particular area, which was in the 

 upper third of the bottom half. The location of the jack was confirmed by counting the jack 

 sequence from a readable number at closer range. During the checking operation it was also 

 necessary to operate the range. During the checking operation it was also necessary to oper- 

 ate the rotary switch in the center of the patch panel (Figs. 158, 159). In one position of the 

 switch, the detent could not be overcome by the wrist-rotate motor torque alone, and thus it 

 was necessary to stall the wrist-rotate motor and then operate the arm-rotate motor to obtain 

 increased torque. Although both functions are driven from identical motors, the loss in the 

 compound gear transmission link, including the worm-gear final reduction of the hand-rotate 

 function, gives rise to a lower stall torque than the spur-gear reduction of the arm-rotate 

 function. 



