This configuration appears at several points in this section, obtained from different sources. This is from American documentation. The gain is 20 and the transistor can be a BC549.
We found this logic level tester in a 1976 documentation. The circuit is powered by the voltage of the...
This is a circuit that appears several times in this section and in articles. It is a preamplifier for...
The unijunction transistor for this circuit, found in a 1976 publication, may be 2N2646. The...