The TK970 crystal oscillator is designed to operate in a dynamic vibration environment while maintaining low phase noise on its output. The oscillator utilizes fi fth overtone SC cut crystal as the heart of the oscillator circuit. This provides the frequency stability and good aging performance of this non-ovenized oscillator. Incorporating a vibration isolation system and a narrow band crystal fi lter, the oscillator maintains excellent phase noise and frequency stability in a severe vibration environment. This unit was designed for use as a low noise frequency reference for radar applications.