Found in a 1924 book by Gernsback, this circuit uses a double variable capacitor, a component not very common at the time. Listening was done on a loudspeaker at the time.
Obtained from an Electronic Engineering of the 90s, these circuits can be applied to almost any...
The components used in this National Semiconductor circuit are not common today, but the...
This electronic ignition circuit was found in Motorola's Linear Databook of 1990. The components are not...