trodes 25, 25a, and 25b surrounded by windings 26, 26a, and 26b, respectively.  The drawing shows the supply lines, 17b, 17c of the cathode and its filament and that of the plate 22a. 

              The basic plan of the electric supply is represented in Fig. 4.  The part 27 feeds an initial branch with low voltage alternating current: this consists of a rectifier 28 (e.g., a Kenotron) whose rectified current is modulated at a frequency variable between 30 and 120 pulses per minute of means of a resistance 29, the control apparatus for which will be described with reference to Figs. 7 and 8.  The current so modulated is passed through the electromagnets 13 and 23 in such a manner as to generate, normal to the cathodes 11 and 17, a modulated field of 10,000 to 20,000 gauss. 

              The part 27 also feeds a variometer (interrupter) 30 which modulates the current of this part at a variable frequency 30 to 120 pulses per minute, the current pulsed in this way serving to feed the remainder of the installation, to wit: The magnetron, 7; 

A converter 31 whose excitation is modulated at a variable frequency 300 to 900 Hz, yielding a doubly modulated current (first at 30-120 pulses per minute, then at 300-900 Hz) which feeds the coils 15, 16 and 26; 

Another converter 32 producing a low voltage direct current modulated at 30-120 pulses per minute by the variometer 30.  This current feeds the motor 21 as well as the motors driving the variometer 30 and the apparatus controlling the resistance 29.

              The current produced by the converter 32 also feeds a voltage step-up apparatus 33 consisting of a vibrator followed by a transformer and a rectifier, and producing a direct current varied at 30 to 120 pulses per minute imposed by the variometer 30.  The maximum value of the voltage produced by the apparatus 33 is, for instance, 300,000 V, but this value may vary up or down, depending on the power one wishes to operate with. 

              The current produced by the voltage step-up apparatus 33 feeds the coils 4b of the cyclotron and 24 of tube 9, as well as a rheostat 34 permitting regulation of voltage to the desired value between 5000 V and 70,000 V.  This voltage is applied to an oscillatory circuit 35 which produces oscillations at a frequency variable at will of wavelength between 1 m and 18 m.  The current available to the output terminals 35a, 35b of this oscillating circuit 35 is thus a high tension current modulated first at 30 to 120 pulses per minute (by the variometer 30) and secondly at a wavelength 1-18 m.  This current feeds the coils 4c and 14; the electrodes, 25a, and 25b are connected to terminals 35a and 35b, respectively, and electrode 25 is connected to the midpoint 35c.- 

              Cathodes 11 and 17, the "dees" of the cyclotron, and the plates 10 and 22, not shown in the diagram of Fig. 4, are connected to the output of the step-up assembly 33, while the heating current for the filaments 11e and 17a is furnished by the resistance 29.