. Practical wireless telegraphy; a complete text book for students of radio communication . hat of a simple coil withoutan iron core. When the telegraph key is pressed and the control circuit of battery B opened,the iron core, in respect to the winding M-1 becomes magnetic, and its self-induction is at amaximum. In this position of the telegraph key, the voltage across the terminals of theradio-frequency alternator is maximum and maximum current flows in the antenna this way the dots and dashes of the Morse telegraph code can be readily formed, andin fact, the signals may be transmi
. Practical wireless telegraphy; a complete text book for students of radio communication . hat of a simple coil withoutan iron core. When the telegraph key is pressed and the control circuit of battery B opened,the iron core, in respect to the winding M-1 becomes magnetic, and its self-induction is at amaximum. In this position of the telegraph key, the voltage across the terminals of theradio-frequency alternator is maximum and maximum current flows in the antenna this way the dots and dashes of the Morse telegraph code can be readily formed, andin fact, the signals may be transmitted at an extremely high speed with a practically non-arcing control. Practically no current is induced in the winding M-2 (the control winding) becauseit includes both legs of the core of winding M-1. It is necessary in this system that theampere turns of windings M-1 and M-2 be practically equal. •Alternate arrangements of this circuit are in use, which are fully described in the April, 1916,Proceedings of the Institute of Radio Engineers. TRANSMITTERS OF UNDAMPED OSCILLATIONS. 269. 1 270 PRACTICAL WIRELESS TELEGRAPHY. For the transmission of speech, a microphone transmitter may be connected in the circuit of B and wireless telephony carried on at large powers. A photograph of a 75 K. W. high frequency alternator of the Alexanderson type appears in Fig. 282. So far, alternators of this capacity have been used for laboratory experiments only, but there is no reason to believe that they will not prove a commercial success, at least at high power land stations. Radio-frequency alternators for the production of lower frequencies, in the region of 30,000 cycles per second, are less difficult to construct than the type just described, on ac-count of the reducedperipheral speed of thearmature. An alterna-tor, for example, gen-erating current at a fre-quency of 30,000 cyclesper second would excitean aerial having a natur-al wave length of 10,000meters and provided theproper output
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
