Audio Level Indicator (CB22046E)

We found this circuit in an old English documentation. The JFET can be any general purpose and the instrument a 50 or 100 uA microammeter.

50 mW Amplifier (CB24449E)
This low-power transistorized amplifier was found in documentation from the 90s. The circuit uses...
Metal Detector (CB12077E)
This circuit is from Popular Electronics from March 1991. It can still be assembled with the...
Symmetric Power Supply (CB15712E)
The voltage of this symmetrical power supply depends on the regulating integrated circuits, which...