Telegraph engineering : a manual for practicing telegraph engineers and engineering students (1922)
Hausmann, Erich, 1886- · New York : D. Van Nostrand Company · leaf 61
Of the four arrangements indicatedthe two which are used in present practice are: the polardifferential duplex and the polar bridge duplex. 2. The Differential Duplex. — The operation of the dif-ferential duplex can best be explained on the basis ofsingle-current operation. This method, known as…
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
