APPLYING CARRIER TELEPHONE SYSTEMS 



559 



than 2| miles. Two lateral cables, each of that length, would have 

 been required in order to make use of this site. Moving the location 

 back to the point where the cables came together would have resulted 

 in an excessively long carrier repeater section and would have located 

 the station within the business section of Wilmington, Del. The 

 problem was to find a compromise site between these two points where 

 the lengths of lateral cables would not be excessive and the repeater 

 section could be kept within desirable limits. A tide water stream 

 between these two points complicated the problem. 



Nine sites were inspected and four of them studied in detail. Flood 

 and fire hazards, as well as high prices of real estate, were added to 

 the other factors governing the choice. None of the locations was 

 entirely desirable, but a compromise choice was finally made of a 

 location which resulted in the longest repeater spacing in the New York- 

 Charlotte project, but the lengths of the lateral cables were reduced 

 to between eleven and twelve hundred feet. 



Table 4 shows the theoretical spacings which, considering the fixed 



TABLE 4 



Comparison of the Originally Specified Carrier Repeater Spacings and 



AcTU.\L Spacings on the New York-Charlotte and 



Detroit-South Bend Cable Routes 



location of existing repeater points, were selected as best from a trans- 

 mission standpoint, and the actual spacings which it was found neces- 

 sary to use. The theoretically best spacings for the two routes differed 

 because of the difference in spacings of the existing voice frequency 

 repeater points of which use has been made as carrier repeater points- 

 Figure 5 shows the repeater office locations as they are distributed 

 on the New York-Charlotte project. The various types of repeater 

 offices shown are discussed later in this paper. 



Direction of Transmission 

 The circuits used for the two directions of transmission of type K 

 carrier systems operate in separate cables on the projects so far com- 

 pleted and, for crosstalk reasons, these two directions of transmission 

 have been transposed between the two cables at each carrier repeater 

 point.2 The location of branch cables and taps to open wire have an 



