This simple general-purpose transistor mixer was taken from an article in Electronics Now magazine in March 1994. You can choose a low-noise transistor such as the BC549.
This crystal radio or galena was found in an English documentation from the 70's. The diode must...
We found this circuit in a 2002 documentation. What it does is put in a reduced power outlet for...
This circuit was found in a 1988 publication. The circuit is an alarm with interrupt sensors that...