This circuit was obtained from the March 1994 Electronics Now magazine. The circuit uses a common transistor which can be a low noise type such as the BC549.
The search coil of this detector consists of 140 turns of wire 18 in an 8 inch diameter form. The...
This circuit was found in a 1989 documentation and was intended to be part of a presence...
In the figure we show a configuration for a crystal controlled overtone oscillator using a...