Abstracts of Technical Articles by Bell System Authors (01 July 1949)

* A. I.E. E. Transactions, v. 67, pt. 1, pp. 557-561, 1948. 596 Electrical Engineering, v. 68, pp. 215-221, March 1949. Metal Progress, November 1948. Proc. I. R. E., v. 37, pp. 258-263, March 1949. ABSTRACTS OF TECHNICAL ARTICLES 597 Recent Improvements in Loading Apparatus for Telephone Cables.6 S. G. HALE , A . L . QUINI.AN, and J. E . RANGES. Through the use of improved materials, manufacturing techniques, and designs, a series of exchange-area loading coils has been provided which is equivalent electrically to the superseded types but requires one-third less copper and has considerably smaller overall dimensions. 

Similarly, 3-coil toll cable loading units have been provided with a saving of one-half in both copper and core material, with a small sacrifice in electrical behavior as compared with superseded types. The reduced size of the new coils and units, together with improved assembly arrangements, made possible a 65 per cent saving in the volume and weight of the cases housing them.

The Coaxial Transistor WINSTONE . KOCK and R . L . WALLACE , J R . The success of the earlier types of transistors led to the exploration of other forms of similar amplifiers, one of which is the coaxial transistor. A description of its construction, characteristics, and many advantages is contained in this article. Paralleled-Resonalor Filters.'' J. R. PIERCE. This paper describes a class of microwave filters in which input and output waveguides are connected by a number of resonators, each coupled directly to both guides.