This circuit, from a component manual, also applies to other components in the same family. The font does not have to be symmetrical, and the characteristics are given next to the diagram.
Found elsewhere in this section, this circuit mimics the noise of a steam locomotive. This was...
This circuit was obtained in an American documentation from the 80's. The transistors can be...
This circuit is from a 60's documentation. The capacitance C1 can be between 20 pF and 0.01 uF...