GB363307A - Artificial line networks for use in telegraphic and like systems - Google Patents

Abstract

363,307. Artificial lines. WESTERN UNION TELEGRAPH CO., 195, Broadway, New York, U.S.A. Aug. 15, 1930, No. 24544. Convention date, Sept. 4, 1929. [Class 40 (iii).] Relates to artificial lines for use in high-speed telegraphy for balancing both the surge impedance and the propagation constant of a loaded or unloaded cable throughout a suitable frequency range. For balancing inductance and reactance, each section of the artificial line comprises two inductances 10, 13, and two resistances 11, 14, and these may be arranged as shown or in several other ways, Figs. 2 .. 6 (not shown). For balancing leakance and capacity, each section comprises one or more resistance-capacity arms 16 in shunt with large condensers 15, the time-constants of the arms 16 being different from one another, while the capacity 15 is distributed throughout the line to a greater extent than the arms 16. It may be shunted by simple resistance also if desired. The Specification shows how the leakance/frequency and capacity/frequency characteristics of the cable can be simulated by adding together the characteristics of the branches 15, 16. The invention is shown as applied to a loaded cable 2 with a non-loaded shore portion 1, these being separately balanced at 4 and 3 as described in Specification 246,429, [Class 40 (iii), Telegraphs, Electric]. Reflections due to discontinuities in the characteristics, of the cable are balanced by means of similar discontinuities introduced into the artificial line.