This oscillator uses a small IF transformer taken from an old transistor radio. FET admits equivalents. The circuit can be used to calibrate radios.
This circuit from an old American publication uses a 12 V transformer and an incandescent lamp in an...
The integrated circuit used in this regulator is quite old. Its 1970s casing is still made of...
This crystal oscillator uses a common transistor and its frequency depends on the crystal used. We...