This oscillator that generates signals below the audible range (sub audio or infrasound) was found in a 1965 documentation. Transistors are for general use.
We found this circuit in a Radio Electronics. The circuit can be seen elsewhere on this site. The...
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit was obtained from an English magazine from 1979, but it can be easily assembled today...