This telephone recording circuit was found in the June 1979 issue of Radio Electronics magazine. The components are common at the time and the power is supplied by the power grid.
Using an operational amplifier, this circuit was found in the March 1996 issue of Electronics Now...
This simple transistor gain test acts as an oscillator for the transistor under test. The circuit is...
Found in a 1980 documentation, this circuit drives a transducer (X1) when the car battery has its...