Transistor gain meter (CB20522E)

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

Variable Filter (CB6239E)
This filter was found in an 80's English publication. However, it can be implemented with modern...
Sinusoidal to Square Converter (CB5105E)
This circuit, which can be used as a shield, was found in old documentation. The circuit must be...
6 500 Gain Amplifier (CB6642E)
Found in Philips documentation from 1968 this circuit operates at frequencies up to 10 MHz with 76...