This circuit for multiple sound inputs was found in a Radio Electronics from January 1992. It consists of a Bargraph connected to a multi-input mixer.
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...