Elementary telegraphy : a manual for students; written specially to meet the requirements of the ordinary grade of the subject as published in the syllabus of the city and guilds of London Institute (1910)
Pendry, H. W. (Henry Walter) · London ; New York : Whittaker & Co. · leaf 84
CD (2) o o C3) Fii:. 4S.—Coiineotioiis of 4-teriiiinal key. (1) Switch to receive ; (2) switchto send, lever at rest; (3) switch to seiifl, lever ilejiresscd. … Fi<i. 40.—r)-teriiiiiial D.f.key-with ailjii.stablicciitaf1.s. circuits. With a(ljusta])le contact screws, i)latiiiuiii con-tacts, mounted on an ebonite slab lixed on a j^olisliedmahogany base, tlie Doul)lo current Vex, five terminal, 74 ELEMENTARY TELEGBAPHY as it is called, is a most…
Telegraph
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