. Practical wireless telegraphy; a complete text book for students of radio communication . g tothe law that the ratio of any oscillationto the one preceding is constant. Thisconstant ratio is called the damping ofthe oscillation and the Naperian loga-rithm of the ratio of one oscillation„. ,, T^ jr. •„ .■ ^° ^^^ preceding one is called the -Highly Damped Oscillations. » ■, t ■ t Logarithmic in the group of oscillations of Fig. 103, the maximum amplitudes ofsuccessive alternations are represented by A^, A^, A^, A*,^ etc., and Ai_A _ Al In terms of logarithms we may write A *wher
. Practical wireless telegraphy; a complete text book for students of radio communication . g tothe law that the ratio of any oscillationto the one preceding is constant. Thisconstant ratio is called the damping ofthe oscillation and the Naperian loga-rithm of the ratio of one oscillation„. ,, T^ jr. •„ .■ ^° ^^^ preceding one is called the -Highly Damped Oscillations. » ■, t ■ t Logarithmic in the group of oscillations of Fig. 103, the maximum amplitudes ofsuccessive alternations are represented by A^, A^, A^, A*,^ etc., and Ai_A _ Al In terms of logarithms we may write A *where e ^= base of the Naperian system of logarithms; = a constant termed the logarithmic decrement. By transposition If we assume that the oscillations in a circuit are extinguished when the ampli-tude of the last oscillation is .01 of the initial oscillation, the complete number ofoscillations (M) in a spark discharge can be computed as follows: Ailog 1-5 M= . AiIf we denote the last oscillation by A then -^ = 100, and since the Logarithm of 100 = Axthen ^, -f «. THE RADIO TRANSMITTER. 91 Hence in a group of oscillationsWhere 8 = + M=- ■ = 47 complete oscillations. The tuning qualities of a train of electric waves from any given transmitting station dependgreatly upon the decrement of the oscillations and, therefore, the determination of the quantity,.^ „ ., „ , „ is an important measurement. It is found 104-Feebly Damped ^^y experiment that a transmitter having less than 24 complete oscillations in theantenna circuit per single spark discharge,possesses undesirable tuning qualities andwill interfere with the operation of otherradio stations not tuned to the same wavelength. A group of 24 complete oscillationscorresponds to a decrement of for acomplete oscillation which is the arbitraryfigure enforced by U. S. Statutes. Thismeans that if the oscillations in agiven antenna circuit have a decrement Aiof , the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
