Transistor gain meter (CB20522E)

This circuit was found in a publication in the 1950s, mainly applying to germanium transistors of the time.

Scale expander for microammeter (CB7363E)
This circuit was found in a 1967 Ferranti manual and can be applied to modern operating...
Sound Intensity Meter (CB11533E)
This ultra-simple meter uses an output transformer and a small speaker as a microphone. The...
High impedance stage (CB20564E)
This high input impedance amplifier stage was found in a 1963 documentation. The transistor...