. Practical wireless telegraphy; a complete text book for students of radio communication . n of inspectors of the American Marconi Company prefer either the hot wirewattmeter, or the crystal detector and head phones as indicators of resonanceabove all others. 162. Uses of the Wavemeter.—The wavemeter may be employed: (1) To place two or more circuits of radio-frequency in resonance; (2) To measure the wave length of the closed or open oscillation circuits ofa radio transmitter. (3) To determine the percentage of coupling between the closed and open cir-cuits of a transmitter; (4) To
. Practical wireless telegraphy; a complete text book for students of radio communication . n of inspectors of the American Marconi Company prefer either the hot wirewattmeter, or the crystal detector and head phones as indicators of resonanceabove all others. 162. Uses of the Wavemeter.—The wavemeter may be employed: (1) To place two or more circuits of radio-frequency in resonance; (2) To measure the wave length of the closed or open oscillation circuits ofa radio transmitter. (3) To determine the percentage of coupling between the closed and open cir-cuits of a transmitter; (4) To determine the decrement of damping; (5) To calibrate a receiving set (by means of an exciting buzzer); (6) To determine the wave length of a distant transmitting station at thereceiving station. (7) To determine the purity of the wave emitted from the antenna. 163. Simple Use of the Wavemeter.—A simple use of the wavemeter isshown in the diagram. Fig. 211, wherein the natural wave length of an aerial isto be measured. In the diagram. Fig. 211, S is the secondary winding of an indue-. x-^<^ Fig. 211—Diagram for Measuring the Natural WaveLength of an Aerial. PRACTICAL RADIO MEASUREMENTS. 191 tion coil fitted with a vibrator, S-1 a spark discharge gap of simple design con-nected in series with the aerial A-1. L is the inductance coil of the wavemeter; Cthe variable condenser; D a crystal rectifier, and P the head telephone. When the induction coil is set in opera-tion a spark discharge takes place at S-1,the aerial circuit being traversed by groupsof oscillations at a frequency determined bythe distributed values of inductance andcapacity of the aerial, or,1N=
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
