Measuring Methods for Maintaining the Transmission Efficiency of Telephone Circuits
F. H. Best · Transactions of the American Institute of Electrical Engineers · 1924
Maintenance of the transmission efficiency of the telephone plant is conducted by a special force using methods and apparatus that have been developed for this purpose. This paper gives a brief description of the transmission characteristics of some of the common types of telephone circuits, outlines a general method for measuring their transmission efficiency and describes several of the most modern types of transmission measuring sets together with a brief mention of the oscillators which supply the power for testing.