1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU42!.3-)33)/.G0G0-%$)!G0G0#(!2!#4%2)34)#3490%3G0G0/appreciatingat the same time that system designers require flexibility in the choice of cables in order to optimize the overallcost per unit length of individua
2、l systems;recognizingthat the most significant cable characteristics in determining whether any two cables may be joined together are:- the inner diameter of the outer conductor,- the characteristic impedance of the cable,recommendsthat for submarine systems handling line frequencies up to 45 MHz the cable used in the deep water sections ofsuch systems should conform with the limits set out in Table 1/G.631.TABLE 1/G.631Inner diameter of outer conductorCharacteristic impedance25.0-25.5 mm43-46 37.0-38.5 mma) 53-54 b) 60-62 43.2 mma) 49-50 b) 53-54 c) 60-62
