This circuit was found in a Radio Electronics from February 1966. With it it is possible to trace the curve of a tunnel diode visualizing it on an oscilloscope.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...