. The Bell System technical journal . X OSCILLATORS 625 by the inductances U , Li, U and the capacitances Ci , C2 , C3. Theseresonant circuits are coupled to the terminals by mutual inductances Wi ,W2, W3. In series with these appears the inductance measured at very lowfrequencies Lq , the self inductance of the couphng loop. The circuit inFig. 114 may be regarded as a symbolic representation to be used in evaluat-ing Z, just as a mathematical expression may be a symbolic representationof the value of an impedance. In practical cases, the resonances are usually considerably separated infrequen
. The Bell System technical journal . X OSCILLATORS 625 by the inductances U , Li, U and the capacitances Ci , C2 , C3. Theseresonant circuits are coupled to the terminals by mutual inductances Wi ,W2, W3. In series with these appears the inductance measured at very lowfrequencies Lq , the self inductance of the couphng loop. The circuit inFig. 114 may be regarded as a symbolic representation to be used in evaluat-ing Z, just as a mathematical expression may be a symbolic representationof the value of an impedance. In practical cases, the resonances are usually considerably separated infrequency, and near a desired resonance the efifect of others may be addition, if the Q is high we may add a conductance Gr across the capaci-tance to represent resonator losses (Fig. 115). It would be equally legiti-mate to add a resistance in series with L. In Fig. 115 a load impedanceZt has been added. Fig. 115 is a very accurate representation of a slightlylossy resonator, a low loss coupling loop, and a load impedance. The. Fig. 115.—Etjuivalent circuit showing connection between the oscillator gap regardedas one pair of terminals and the oscillator load for an oscillator resonator having only oneresonant frequency near the frequency of operation. meaning of L and C will be made clearer a little later. We will now clarifythe meaning of m. Suppose no current flows in the coupling loop (Z = co ).Let the peak gap voltage be V. The peak voltage across m will be F„, = mV/L (a4) In a resonator, if a peak voltage V across the gap produces a peak flux \p,nlinking the coupling loop when no current flows in the coupling loop, then F„, - d^p^Jdt = tnV/L (a5) This defines m in terms of magnetic field, and L. Figure 115 is also a quite accurate representation of Fig. 113. In thiscase the terminals are taken as located at the end of the wave is the inductance of the iris, which will vary with frequency. When we are interested in the impedance at the gap as a functio
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