This medium wave radio works with any general purpose NPN transistor. The diode must be made of germanium and a coil formed by 50 + 50 turns of wire 26 to 30 on a ferrite rod.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....