This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be done based on transistors with known gains.
This circuit is from a Popular Electronics from the 90's. It can be implemented with equivalent...
This two-transistor preamplifier was found in a 1960 Sylvania transistor manual. The output...
The gated oscillator shown here turns on when a “1" Iogic Ievel is applied to the input. The...