558 BELL SYSTEM TECHNICAL JOURNAL 



repeater stations, known as auxiliary repeater stations, will be con- 

 structed. The selection of these locations is necessary before the 

 transmission design of a carrier route can be completed. Repeaters 

 for voice frequency circuits are located on existing cable routes at an 

 average spacing of about 45 miles. These same offices are used as 

 cable carrier repeater points, but, because of the high losses at carrier 

 frequencies, two additional carrier repeater stations, on the average, 

 have been provided between each two voice frequency repeater offices. 



The cables and routes having been tentatively decided upon, the 

 route records were studied and locations which were the most prac- 

 ticable from a transmission standpoint were selected. These selections 

 were influenced by the expected maximum section losses, taking into 

 account aerial and underground construction. In general, the dis- 

 tances between the existing voice repeater points were divided into 

 the smallest number of equal parts, the lengths of which did not 

 exceed the maximum permissible carrier repeater spacing, and repeater 

 station sites were tentatively located at the junctions of these parts. 



A physical inspection of these tentative sites was then made and 

 where necessary an alternate site selected. Such factors as accessi- 

 bility of site, suitability for building, availability of primary power, 

 cost of real estate, and willingness of owners to sell determined whether 

 or not the tentative site could be used and, if not, what alternate 

 location might be used. Where a suitable existing telephone building 

 happened to be located near a proposed repeater station location, the 

 possibility of using such building was studied. It has been practicable, 

 however, in only one instance to use an existing building in installing 

 the 34 auxiliary stations provided to date. The sites which were con- 

 sidered satisfactory after the physical inspection were then examined 

 to check their suitability from a carrier transmission standpoint. In 

 cases where transmission limits had been exceeded, the sites were 

 reinspected and compromise locations finally agreed upon. In most 

 cases it has not been difficult to find sites which are suitable both from 

 a transmission and a construction standpoint. Of the 34 type K 

 carrier repeater stations which have been built, 20 were constructed 

 at the sites originally selected from a transmission standpoint. In 

 most of the other cases the final sites were within a short distance of 

 the originally selected locations. In a few cases, however, where ideal 

 sites fell in populous centers or comparatively inaccessible wilds, it 

 was necessary to take unusual steps. 



In one case the site which had been selected from a transmission 

 standpoint fell at a location where the two cables which had been 

 selected followed different conduit runs and were separated by more 



