This filter for frequencies from 300 Hz to 3.4 kHz was found in the February 1995 Radio Electronics magazine. Other operational amplifiers can be experimented, and the source must be dual.
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...