. Practical wireless telegraphy; a complete text book for students of radio communication . the shaft . and a suitable scale supplied. The ball ^^^ ^^ mm^^JHM wintek windings A and B are connected in series and if, in one concentric position, they are :onnected so that their magnetic fields op-pose the inductance of the variometer will be practically zero, but if the inner ball is turned on its axis, the inductance will gradually increase, maximum inductance being obtained, when the inner coil has completely changed sides with respect to the outer coil. For receiving apparatus, the inner and o
. Practical wireless telegraphy; a complete text book for students of radio communication . the shaft . and a suitable scale supplied. The ball ^^^ ^^ mm^^JHM wintek windings A and B are connected in series and if, in one concentric position, they are :onnected so that their magnetic fields op-pose the inductance of the variometer will be practically zero, but if the inner ball is turned on its axis, the inductance will gradually increase, maximum inductance being obtained, when the inner coil has completely changed sides with respect to the outer coil. For receiving apparatus, the inner and outer balls are generally wound with No. 24 B. and S. wire if connected in the antenna circuit and with No. 32 B. and S. wire, if connected in series with the secondary or detector circuit. Although the variometer is a very useful instrument for tuning the re-ceiver, it possesses the disadvantage of offering considerable resistance to the passage of radio-frequent cur-rents when used at inductance values near to zero. That is to say, a sim- Fig. 192—The Construction of the Fig. 193—The Tuning Variometer Complete. *See paragraph 30; also fig. section H appendix. RECEIVING CIRCUITS, DETECTORS, TUNING APPARATUS. 167
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
