. QST . may be ob-tained from a 100-kc. crystal. Includedis a series of graphs that help to explainthe manner in which the circuit works. think the results would be of interest to otherhams. Circuit Operation It was immediately apparent that the expla-nation offered in the original article is grid resistor has little effect on the frequencyof the subharmonics. The cathode by-pass capaci-tor is likewise ineffective, although there is anoptimum range for both these components intheir effect on the stability of operation. The proper explanation seems to be that therelaxation pulse f
. QST . may be ob-tained from a 100-kc. crystal. Includedis a series of graphs that help to explainthe manner in which the circuit works. think the results would be of interest to otherhams. Circuit Operation It was immediately apparent that the expla-nation offered in the original article is grid resistor has little effect on the frequencyof the subharmonics. The cathode by-pass capaci-tor is likewise ineffective, although there is anoptimum range for both these components intheir effect on the stability of operation. The proper explanation seems to be that therelaxation pulse from the screen circuit is fedto the LC network composed of L, Ci and Czthrough the crystal operating at near its seriesresonant frequency. A transient oscillation isexcited in the tuned circuit which, for , has a frequency of 350 kc. Thus thegrid signal consists of the resonant frequency ofthe crystal with the frequency of the tunedcircuit superimposed upon it (Fig. 2A). The CSC. Fig. 1 — Circuit for ob-taining subinterval mark-ers from a 100-kc. capacitances less lit. are in /i/if. Ci andC2 are SO-^i/jf. air trim-mers. All resistors }/2 watt,unless otherwise — Power transformer:750 , 40 ma.; 5 volts,2 amp.; volts, 2 amp. 22 QST for Bottom view of thecrystal calibrator. positive crests of this complex wavetrigger the tube in such a way that thescreen voltage appears as in Fig. 2B,and the output voltage as in Fig. is little or no synchronizing action, sincethe crystal does not feed back any of the 350-kc.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
