. Practical wireless telegraphy; a complete text book for students of radio communication . varied until the maximum strength of signals is protect the filament and assist adjustment, modern sets have a small ammeter connectedin series with the lamp filament by which the degree oj incandescence is definitely fixed. 143. A Repeater Vacuum Valve Circuit.—A method for repeating, thecurrent of radio frequency flowing in the telephone circuit back to the grid circuitof the same bulb appears in Fig. 181. This system has been found to be particularlysuccessful in operation and gives incre
. Practical wireless telegraphy; a complete text book for students of radio communication . varied until the maximum strength of signals is protect the filament and assist adjustment, modern sets have a small ammeter connectedin series with the lamp filament by which the degree oj incandescence is definitely fixed. 143. A Repeater Vacuum Valve Circuit.—A method for repeating, thecurrent of radio frequency flowing in the telephone circuit back to the grid circuitof the same bulb appears in Fig. 181. This system has been found to be particularlysuccessful in operation and gives increased strength of signals from a given sta-tion. Part of the energy of the oscillations of radio-frequency flowing in thetelephone circuit is repeated back to the secondary circuit through the couplingcoils (of radio-frequency) L-1 and L-2, and the amplitude of the grid oscillations• thereby increased. The amplified grid oscillations then react upon the telephonecircuit, producing still greater variation of the local current, thus further reinforc-ing the oscillations of the ^^y^ Fig, 182—Audio-Frequency Repeater Circuit. Fig. 183—Tuned Regenerative Vacuum Valve Circuit. The complete process does not interfere with the action of the valve as a detector,which at the same time charges the grid condenser in the usual fashion, but with in-creased strength, due to the repeating action of the system. To permit the oscillations of radio-frequency to flow across the telephones, the con-denser C-3 is connected in shunt. This circuit will function without the condenser C-3,the necessary capacity being found in the parallel cords of the telephone. The current of audio-frequency flowing in the local telephone circuit may be repeatedto the grid circuit by the method shown in the diagram of connections. Fig. 182, wherea coil of audio-frequency (one of large inductance values) L-1 is coupled inductivelyto a similar coil, L-2, which is connected in series with the secondary win
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
