This circuit was found in a Philips documentation from 1970. The components are of the time, difficult to find today, but the configuration can be adapted to use modern equivalent components.
This flood or humidity alarm was found in an English publication in 1991. It can still be fitted...
This simple transistor tester uses a common 3 mA analog instrument that has its scale changed as...
This RF amplifier step has a dynamic range of 140 dB and can amplify signals from 0.5 to 40 MHz....