Multi Neon Tester (T457E)

This circuit was found in Popular Electronics from March 1968. It is intended to be tube circuit proof as it operates at high voltages.

15 W Near Complementary Amplifier (CB6280E)
This circuit was found in an Electronics World of 1968, making use of components of the time, not...
Picoammeter (CB6194E)
This 80's General Electric circuit is guarded by the noise-guard for operating current. The...
RTD Bridge with Operational (CB4393E)
The circuit shown in the figure below is from the 1993 Linear Technology Applications. The...