INDUCTIVE LOADING FOR TELEPHONE FACILITIES 



185 



performance, greatly increased the demand for service, up to the beginning 

 of the business depression in the early 1930's. 



CABLE A 



CABLE B 



Fig. 9— Installed aerial toll cable loading. Four different methods of supporting the 

 loading-coil cases are used in this installation, which provides loading for two cables: 

 (a) On the platform of a 2-pole "H" fixture. (1 large welded steel case, and 5 large cast 

 iron cases.) (b) A pole balcony supporting a large welded steel case. In this installation, 

 it provides an extension of the "H" fixture, (c) A small welded steel case equipped with 

 brackets, and fastened directly to pole, (d) Clamping a small lead-sleeve case to the 

 main cable and its supporting strand. (This case contains program circuit loading coils.) 



Around 1930, improved assembly-arrangements were worked out for the 

 permalloy-core loading units. These involved the assembly of the individual 

 loading units in individual unit-containers, and the code designations were 

 changed. These used the letters 'TB", and the same numbers as in the P- 

 type units; the complete designations being PIB, P2B, etc. 



