TRANSCONTINENTAL TELEPHONE LINES 245 



Wire 165 mils in diameter was used on this construction west of 

 Oklahoma City because of its strength and resultant relative freedom 

 from interruptions. Transmission losses were also a factor in this 

 case. Rolled sleeve joints were used in splicing the wire because of 

 their strength and good electrical characteristics. Flat tie wires, 

 shown in Fig. 4, were used to reduce chafing of the line wire when 

 the wires vibrate. Tie wires are not used at transposition points, as 

 may be seen in Fig. 3. 



Repeater Stations 



The computed losses on open-wire pairs of this type at high-carrier 

 frequencies and under different weather conditions are shown by Fig. 5. 

 Field tests confirm these data. To off"set the line losses it will be 

 necessary to locate repeater stations at intervals of from fifty to one 

 hundred miles, depending upon the weather conditions which may 

 be expected. Between Oklahoma City and Whitewater, California, 

 in order to operate the twelve-channel carrier telephone systems, it will 

 be necessary to equip sixteen intermediate repeater stations. Most of 

 these will be unattended and maintained from other offices. 



It is not practicable, of course, to bring the open-wire pairs directly 

 into all repeater stations and in some cases entrance cables several 

 miles long must be used. Although ordinary non-loaded cable pairs 

 may be used for this purpose, their usage involves transmission diffi- 

 culties, and except where other factors dictate the use of this type of 

 facility, it is planned to use low-loss cable conductors of a new design. 

 These cable pairs have more favorable impedance characteristics as 

 well as lower losses. 



With the building and the further equipping of this latest open-wire 

 line across the western states, open-wire facilities have played one 

 more important part in the development of long-distance telephony. 

 Although cable is being found more and more useful, there still remain 

 many important links in the nation-wide telephone communication 

 network where, for the present at least, the open-wire line can serve 

 best and the development of it toward maximum usefulness is still being 

 carried on. 



