video-modulated signal for optional use of additional monitors. 

 Around this basic component the underwater television vehicle was 

 constructed. Actually several modifications were necessary for use 

 at relatively low light levels imposed in undersea use. For photo- 

 grsphing the monitor screen the picture quality required fine control 

 of light, A Service engineer ad^ted a simple differential gearing 

 principle to the existing manual optical focus system to provide remote 

 lens-aperture control of l6mra. C mount or wide angle lens in a range 

 of f 2.8 to f 22.0 (fig. 7). 



1800 RPM REVERSIBLE 

 IRIS CONTROL 

 DRIVE MOTOR 



IRIS CONTROL RING GEAR S 



OPTICAL FOCUS HOUSING 



OPTICAL FOCUS COUPLING RING GEAR 



(INTERNALLY MOTOR DRIVEN) 



Fig. 7. Remote Iris Control Device for Modified R.G.A. Model ITV-5 

 Industrial Television Camera. 



POWER SUPPLY 



A reliable and stable source of 110 volt AC 60 cycle power was 

 important to operate the commercial television equipment. To insure an 

 adequate power supply, a 3 KW generator was used with motor generator 

 set and voltage regulator. Portable povjer units were used satisfactorily 

 but television performance was found to be only as reliable as the power 

 source. A separate source of 2ii volts DC power was used for the scanning 

 drive unit. 



11 



