NPN and PNP transistor tester (CB22146E)

This simple transistor tester was found in old English documentation. Suitable for general purpose transistors.

Ultra simple Transistor Radio (CB16224E)
We found this elementary receiver in a 1983 publication, but it can be easily assembled today, as any...
0.01 Hz to 7 MHz TTL Astable (CB13814E)
This oscillator was found in a 1976 documentation. The no specified components indicate circuit...
Varicap in the Tuning Circuit (CB4102E)
The figure shows how to use a varicap in a conventional tuning circuit. The circuit may be an...