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. (The) oscillation valve in the transmission and reception of radio messages . OpenCircuit A = AerialL-3 = Loading InductanceL-1 = Primary Receiving Tran 5for me C-3 = bhort wave CondenserG = Ground L-2 = Secondary of Receiv-) C-1C-2 TD ing TransformerVariable CondenserShunt CondenserTelephonesRectifier or Detector ) Closed(Circuit The open and closed circuits shown in Fig. Ill areinductively coupled. Conductive or direct coupling may be usedas in Fig. IV, or the so called electrosttitic coupling in Fig. V. c. Thousands of variations of the above threefundamental types of circuits are in use.
. (The) oscillation valve in the transmission and reception of radio messages . OpenCircuit A = AerialL-3 = Loading InductanceL-1 = Primary Receiving Tran 5for me C-3 = bhort wave CondenserG = Ground L-2 = Secondary of Receiv-) C-1C-2 TD ing TransformerVariable CondenserShunt CondenserTelephonesRectifier or Detector ) Closed(Circuit The open and closed circuits shown in Fig. Ill areinductively coupled. Conductive or direct coupling may be usedas in Fig. IV, or the so called electrosttitic coupling in Fig. V. c. Thousands of variations of the above threefundamental types of circuits are in use. The open and closed oscillation circuits (or theantenna and datector circuits) must be tuned to closeresonance in any two circuit receiving system, in order toget the maximum value of the oscillating E. M. F. v/hich isimpressed across the terminals of the detector. The use ofcrystal rectifiers does not require such care and precisionin tuning as some of the vacuum tube circuits to be describedlater. HISTORY OF THE OSCILLATION VALVE Dr. J. A. Fleming of London was the first to employthe emmission of electrons from heated metals, to rectify ordetect radio frequency oscillations in a wireless telegraphreceiving system. He called his product a glow lamp oscillationdetector, or oscillation valve. He adopted the latter name,because he found that the lamp would conduct electricity betterin one direction than in the opposite. Thus, if the valve was connected to a source ofradio frequency oscillations, one-half
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Keywords: ., bookcentury1900, bookdecade1920, bookidtheoscillati, bookyear1922