Transistor Sine Wave Oscillators-Squegging and Collector Saturation

The previous analysis of the amplitude limiting properties of transistor sine wave oscillators is extended to include the calculation of self-modulated or squegging conditions as well as the effects of collector-base diode saturation. The conditions for avoiding squegging are clearly defined in terms of known or directly measurable circuit parameters. If squegging is desired then a clear boundary is established between initial squegging that is sinusoidal and initial squegging that is exponential. For sinusoidal frequency squegging the squegging frequency is shown to be of the form
(ql_{DC}/kT)(1/C')(f(x))
where C' is a circuit parameter and
f(x)
is a plotted function of the oscillator feedback voltage.