hull: tr.\nsmitter of modulated waves 



319 



reduced power, it is necessary to make the number of turns in 

 the compensating winding adjustable. The compensating wind- 

 ing of the transformer is composed of 100 turns No. 16 d. c. c. 



/Jutematic Sender 



To 



ISO volt 



500 cuc/e 



Genera toih 



Fig. I. Diagram of connections of modulated- wave transmitter. — A. 

 Plate and grid coupling coils. Continuous coil wound on fibre tube 5 'A" in diam- 

 eter. 80 turns No. 18 solid wire spaced Vs" apart; and taps brought out every 5 

 turns on grid side and every ten turns on plate side of coil. B. Antenna switch. 

 D. Generator field rheostat. E. Electron tube, type P pliotron. F. Antenna-coil; 

 30 tums-litzendraht, wound on fibre tube (i^ j ^' in diameter; taps brought out every 

 two turns; mounted so as to slide over coupling coil, in order to vary mutual induc- 

 tance. G. Stopping condenser ; mica ; C = 0.004 ™fd. H. Automatic sender, driven 

 by D. C. motor, which is supplied from the field circuit of alternator. L2. Filament 

 ammeter, /i. Antenna ammeter. R. Filament rheostat. T. Supply transformer, 

 2 kva.; ratio of turns, 40/1 ; full load voltages, 160/6500. Tj. Filament transformer, 

 special construction. The main windings consist of 200 turns No. 16 d. c. c. wire 

 on the prirnary side, connected across the 180- volt supply, and 120 turns No. 16 

 d. c. c. wire on secondary side, connected to filament circuit. 



wire, with a tap every twelve turns from 30 to 100. The fila- 

 ment rheostat makes it possible to adjust the filament current 

 for any steady value of primary voltage on the transformer; 

 the series compensating winding makes it possible so to adjust 

 the transformer to the supply circuit that the filament current 



