This 1968 Hughes circuit uses period components and operates at 8 Hz. Current equivalent components may be employed. Note the high supply voltage.
This circuit, found in documentation from the 1980s, uses an operational amplifier from that time....
This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational...
This circuit was found in a 1980s documentation. It is intended for remote vibration monitoring...