. An elementary manual of radiotelegraphy and radiotelephony for students and operators . ught into apposition, as the continualaction of the spark erodes or cuts away material from the sparkballs, leaving them rough. The general appearance of a Marconiship transmitter is as shown in Fig. 8, which gives a view ofthe Marconi transmitting api)aratus used on board ship, the setcomprising a motor-alternator for producing the alternating currentwhich is seen below the table, and the spark balls, condenser andoscillation transformer on it. At one time it was considered an advantage to divide the spa
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . ught into apposition, as the continualaction of the spark erodes or cuts away material from the sparkballs, leaving them rough. The general appearance of a Marconiship transmitter is as shown in Fig. 8, which gives a view ofthe Marconi transmitting api)aratus used on board ship, the setcomprising a motor-alternator for producing the alternating currentwhich is seen below the table, and the spark balls, condenser andoscillation transformer on it. At one time it was considered an advantage to divide the spark up between several spark surfaces by putting balls in series, but this does not appear to be the case, and it is usual now to employ a single spark gap. A view of a fixed single park gap is shown in Fig. 0. 2^6 RADIO TELEGRA PH V When an inductive coupled transmitter is being used consistingof a radiator or antenna coupled to a condenser energy storingcircuit, as shown in Fig. 7, then as long as the spark at the sparkballs endures the primary condenser and inductance forms a closed. Fig. 8.—View of Marconi Ship Wireless TelegraphTransmitting Apparatus. circuit, and the reaction between the current in it and thecurrent induced in the open antenna circuit gives rise to theproduction of a complex oscillation as already explained, whichis resolvable into oscillations of two frequencies. To avoid thisdivision of the energy it is now usual to employ some form ofquenched spark gap which has also the property of producingspark discharges of high frequency and of extremely regularoccurrence to form what is called a musical spark. KA DIG TELEG RA PI/IC S TA !47 It has btiMi ulivftdy ineiilioiu«i that when two siiuxtlli thickCKjiper plates nro jthued very near to each other, say half amilliinetro, with surfaces perfectly jKinillel, a condenser dischargemade to take place between theui, the discharge does not endure,but is soon quenched or arrested by the cooling action of the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
