SOME APPLICATIONS OF TYPE "J" CARRIER SYSTEM 347 



With these selections of entrance cable facilities and tentative 

 repeater station locations, the distribution of gain and line loss by 

 repeater sections is shown in Table I. A satisfactory distribution of 

 line loss has been obtained and an analysis of these data shows that 

 further improvement is impracticable. Therefore, the tentative 

 repeater station locations were adopted. 



Figure 4 is a diagram of the major line and equipment parts of the 

 Dallas-San Antonio lead. The J carrier path is shown by heavy solid 

 lines, the C and voice on the same wire with the J by light solid lines, 

 and all other circuits, classed as non-J, by dotted lines. Figures 5 to 8, 

 inclusive, show in more detail the arrangements at the huts and 

 repeater stations. The figures for the Dallas Hut and Temple Re- 

 peater Station are typical, and huts and unattended repeater stations 

 not shown differ from these only in minor details. It will be noted that 

 all wire on the toll line is brought through the repeater stations while 

 only that wire on which J carrier is superposed is routed through the 

 huts except at Austin where all wire to the north is brought through 

 the hut to allow the future application of crosstalk suppression filters if 

 required. For both huts and unattended repeater stations, short 

 lengths of loaded spiral-four conductors are used from the six-inch 

 spaced wire at the terminal poles to the equipment in the buildings. A 

 single continuously adjustable load unit is used for each pair and is 

 located with the equipment. Paper insulated pairs under the same 

 cable sheath as the spiral-four conductors are used for the non-J wire. 



As previously mentioned, the conditions at Austin were complicated 

 by a single cable for existing circuits and a new cable for J carrier in 

 both directions. Figure 9 is a diagram of the existing and new cables 

 to the filter hut and terminal poles, and Fig. 10 shows the inter- 

 connection of circuits and equipment used at the filter hut, terminal 

 poles, and central office. 



Terminal and repeater equipment in existing offices is located in 

 space adjacent to other equipment terminating toll circuits, and makes 

 use of the common office equipment and power plant. The relation of 

 the J carrier terminals to the other equipment in the Dallas Toll Office 

 is shown in Fig. 11. 



The new repeater stations and the filter huts are arranged for 

 unattended operation. The equipment in the filter huts is such that no 

 adjustment or attention is required other than periodic inspections. 

 In the unattended repeater stations the power supply equipment is 

 automatic in its operation. Although periodic maintenance attention 

 is necessary, it is desirable that any abnormal condition be recognized 

 as soon as practicable and a system of alarms has been provided from 

 each unattended station to an adjacent main repeater or terminal 



