A study of an artificial telephone line

Citation

Swedlund, Lloyd E. (1928) A study of an artificial telephone line. Master's thesis, California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-02252005-132801

Abstract

The purpose of this study was to perform tests on an artificial telephone line to illustrate the fundamental principles of telephone transmission line phenomena. The artificial line and the equipment used with it was given to the California Institute of Technology through the generosity of the companies associated with the American Telephone and Telegraph Company. It was designed primarily to be operated as a telephone line although resistors are provided which can be short-circuited to make the line equivalent to a power circuit. The tests described in this study were taken only when the line was connected as a telephone line. The tests included measurements of the distribution of current, voltage, and impedance at a number of frequencies in the voice range with different terminal conditions of the line. The effect of loading was studied by the use of shunt resistors. Resonance, reflection, and the Ferannti effects were also observed and measured. The value of an artificial line lies in approximating or actually reproducing the conditions in a real line, so this line was investigated to see how nearly it behaved as a real line.

Thesis Files