One of the important requirements on oscillators is to have stable frequency of oscillation. The frequency stability problem for vacuum tube oscillators has been extensively in-estigated

however

the same problem for transistor oscillators has not been adequately treated. It is therefore the purpose of this paper to offer a detailed analysis on the frequency stability of transistor feedback oscillators.General equation of oscillations for feedback oscillators are first derived by using the linear analysis based on the cascade parameter matrix representation of 2-port networks. Analysis is then applied to the various types of transistor feedback oscillators. Various types of the equivalent circuits for the common-emitter network and various forms of feedback networks using only pure reactive elements are used in deriving the equationsof oscillations. Elements of the feedback networks are assumed to remain unchanged andparameters of the transistor networks are assumed to be varied in the investigation of the frequency drift of transistor oscillators.Feedback networks are grouped into three major groups according to their geometries: the three-arm π configurations

the four-arm and the five-arm configurations. Conditions of oscillations

conditions of frequency stability for oscillators using these groups of feedback networks are discussed and results are summarised into three tables for ready references.