This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
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....