This circuit was obtained from an Electronics Design of 1964. The circuit makes use of tunnel diodes that are uncommon today. The circuit works with very weak signals.
This circuit was found in 80's Popular Electronics. Transistors are commonly used. The...
This low current source uses some components that are hard to find in ours. The transformer is a...
This circuit is from a manual based on information from Japanese components from 1981. The power...