. Practical wireless telegraphy; a complete text book for students of radio communication . L a radio-frequency coilconsisting of a few turns of rather coarse wire or copper tubing (without an iron core).S-1 is the spark discharge gap, the usual form being two brass or zinc rods about ^ inchor less in diameter. When current is flowing through the primary winding P, with correct separation of thespark gap electrodes, a violent spark discharge will take place following each alternation THE RADIO TRANSMITTER. 83 of the charging current or at the points, A, B, C, D, E and F shown. The discharge up
. Practical wireless telegraphy; a complete text book for students of radio communication . L a radio-frequency coilconsisting of a few turns of rather coarse wire or copper tubing (without an iron core).S-1 is the spark discharge gap, the usual form being two brass or zinc rods about ^ inchor less in diameter. When current is flowing through the primary winding P, with correct separation of thespark gap electrodes, a violent spark discharge will take place following each alternation THE RADIO TRANSMITTER. 83 of the charging current or at the points, A, B, C, D, E and F shown. The discharge uponanalysis is found to consist of groups of radio-frequent oscillations which alternate throughthe condenser and inductance at an extremely rapid rate* per second of time. More clearly,if the frequency of the charging current is SCO cycles per second (or 1,000 alternations), thecondenser C will be charged 1,000 times per second and 1,000 spark discharges will take placeat the gap S. This will result in the flow of 1,000 groups of radio-frequent oscillationsthrough the discharge Fig. 94—Complete Cycle of Events in the Discharge of a Condenser. The term spark frequency is employed to designate the number of spark dis-charges, bridging the gap per second of time. In certain types of radio sets thespark frequency equals the alternations of the charging current, but in othertypes the frequency of the sparks may vary in accordance with the general designof the apparatus (to be explained in the chapter following). 87. Analysis of a Spark Discharge.—A spark discharge such as thatcreated by the condenser Fig. 94 consists of a series of cycles of alternating cur-rent of constantly decreasing amplitude, the frequency of which may be verygreat. These are known as damped oscillations, a single group of which areshown in Fig. 89. The complete cycle of events in the discharge of a condenser may be summarized asfollows: Referring to the diagrams. Fig. 94-a-b-c-d-e: Just previous
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
