. Practical wireless telegraphy; a complete text book for students of radio communication . longer wave,Xj^ =: shorter true coefficient of coupling is obtained from the following formula; M K=- Where M =mutual inductance of the oscillation transformer,Lj =self-inductance primary,L, =self-inductance secondary. •Statements (1), (2) and (3) apply to all coupled transmitters of the American Marconi Company. 196 PRACTICAL WIRELESS TELEGRAPHY. 168. Plotting of Resonance Curves.—A calibration of the closed andopen circuits of a radio-transmitter is frequently desired to determine, let us say
. Practical wireless telegraphy; a complete text book for students of radio communication . longer wave,Xj^ =: shorter true coefficient of coupling is obtained from the following formula; M K=- Where M =mutual inductance of the oscillation transformer,Lj =self-inductance primary,L, =self-inductance secondary. •Statements (1), (2) and (3) apply to all coupled transmitters of the American Marconi Company. 196 PRACTICAL WIRELESS TELEGRAPHY. 168. Plotting of Resonance Curves.—A calibration of the closed andopen circuits of a radio-transmitter is frequently desired to determine, let us say,the variation of frequency or wave length occasioned by the insertion of a certainamount of inductance. The results of such measurements are plotted on cross-section paper in the form of a curve (or perhaps a straight line). The principaladvantage of such plotting lies in the fact that it enables one to take a character-istic set of readings at two or more decisive points and thus determine interme-diate values by following the general outline of the curve. Aerial TuningInductance. CondenserScale WATTMETER- Fig. 217- -Complete Apparatus for Measuring Decrement of Antenna Oscilla-tions and Plotting a Resonance Curve. The resonance curve of the radiated wave of a transmitter is a graphic way of showingthe relation between the amplitude of the current and the frequency or wave-lengths at andnear the fundamental frequency. The value of the plotting lies in the fact that it enablesthe experimenter to obtain, in a general way, the over-all distribution of energy in the emittedwave, the decrement of damping and the relative power of the two waves, if present. To plot the resonance curve of the radiated wave, a waveraeter is required, in serieswith which is connected either a hot wire milliammeter or a hot wire wattmeter. Themilliammeter should have a range of, say 40 to 240 milliamperes, while the wattmeter mayhave a scale reading of .01 to .1 watt. The latter instrument is prefe
Size: 1508px × 1657px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
