. A study of wireless telegraphy and wireless telephony . at from New York to San Francisco,recently opened with impressive ceremony. In wireless telephony, the wires 1-^ and 12 are removedand unchanged electromagnetic waves employed instead. In brief,in wireless telephony, we need: (a) An arrangement for generating the undamaged electricwaves in the transmitter. (b) Means for modulating the amplitude of these wavesin accordance with the wave form of artificial speech. (c) An arrangement for receiving these electric waves ofvariable amplitude, and causing them to affect a speaking telephone. T
. A study of wireless telegraphy and wireless telephony . at from New York to San Francisco,recently opened with impressive ceremony. In wireless telephony, the wires 1-^ and 12 are removedand unchanged electromagnetic waves employed instead. In brief,in wireless telephony, we need: (a) An arrangement for generating the undamaged electricwaves in the transmitter. (b) Means for modulating the amplitude of these wavesin accordance with the wave form of artificial speech. (c) An arrangement for receiving these electric waves ofvariable amplitude, and causing them to affect a speaking telephone. To produce the persistent train of waves of high frequencynecessary, several methods are used, such as: 1) The singing arc method (see p /9 ) 2) The mercury arc method. 3) The high frequency alternator method, mercury arc method is shown in Fig. 39. It consistsof a glass tube T, pumped to ahigh degree of vacuum. To it areattached two carbon anodes A andE and a mercury cathode K. D isa generator to establishan arc, and E is a small auxilliary. Vreelands Oscillator. 54. electrode to help stare this arc in the chamber. /.hen this arcis established, it will be seen to divide into two branches--one between A and K, the other between B and K. The resistanceR and the choke coils L and are used to steady the two arcs,between the two anodes A and B is connected an oscillation cir-cuit, containing a condenser U and two coils FP^, the functionof the latter by their magnetomotive force being to deflect thearc inside the vacuum bulb, and to cause the cathode stream ofthis arc to oscillate in a plane perpendicular to the axis of thecoils in such a manner that this oscillating cathode stream im-pinges first on one and then on the other of the anodes A and deflection of the cathode beam is produced due to the factthat the two parts can not keep equal conductivities alter thearc has been established, and this causes irregular fluctuationswhich in turn give ri
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1915
