This circuit can detect static charges or extremely low voltages. The circuit was found in ancient American documentation and makes use of a JFET. A BF245 which is a more modern transistor can be used.
Unlike white noise, pink noise has a spectrum whose amplitude decreases with frequency. This...
We found this circuit in the April 1992 issue of Radio Electronics magazine. The circuit uses an...
This circuit sends its signals through a wall acting as an FM spy. The circuit is from an...