Microphone preamp (CB22043E)

This preamp was found in an old English publication. Any usage JFET can be employed. The output is high impedance.

Transistors and Diodes Tester (CB18658E)
This simple circuit makes it possible to test diodes and transistors for generating use and medium...
1 to 25 V power supply (CB8892E)
This 2.5 A power supply was found in a 90's QST magazine. The power transistor must be mounted on a...
Digital capacitance control (CB7552E)
This circuit is a digitally controlled variable capacitor. We found it in American documentation from...