







e =0.185 



e = 0.19 



9 





9=0.18 









8 



~ 











7 



- 











•D 



- 











o 



^' 



D 

 Z 



uu 

 < 



- 











3 



- 











2 



- 









1 



- 



, AL 



L 



12 3 4 5 6 



RADIUS, cm 



Figure 9. Sensitivity of various modes to curvature. 



Figure 10 is a plot of spool length as a function of OD given an ID of 5 inches and 

 cable lengths of 5 km and 10 km. Plots are shown of cables of several different diameters to 

 show the effect of a slight reduction in cable diameter on the spool volume. 



3.1.4 PROGRESS TO DATE 



Several key cable measurements were done in FY 80. These included 



— Attenuation changes attributable to ruggedizing the bare fiber to the 

 finished cable form. 



— Attenuation change attributable to precision-winding the cable into a 

 self-standing spool. 



— Attenuation changes attributable to operating pressure levels. 



— Excess attenuation during payout attributable to bending at the peel-off 

 point. 



24 



