PERFORMANCE INDEX OF QUARTZ PLAlliS 



237 



VOLTAGE ACROSS CRYSTAL TERMINALS 



Fig. 15.8 — Observed variation of Performance Inde.x as a function of voltage across the 



crystal terminals. 



60 



"■ < 



U DC 



>- o 



t i 



O 1 



< o 



5 20 



DECREASING 



40 60 80 100 80 60 40 



PERCENT OF MAXIMUM Ig WITH 



VARIATION OF PLATE TUNING 



P"ig. 15.9 — Observed variation of effective crystal capacitance in a Miller oscillator. 



