This fader or fader was found in a 90s Popular Electronics. The circuit uses transistors that are equivalent to BC548. Input and output cables must be shielded.
Found in a Philips publication from the 1970s, this circuit uses a DO040, which is difficult to obtain...
This circuit was found in a 1978 American publication. It beeps if the car's lights are on and the...
This circuit is from an Electronics World of 1964. The circuit can be made with modern...