This circuit uses a parallel resonant crystal to control the frequency. The circuit is from Radio Electronics magazine, February 1993. Equivalent transistors can be used.
With the first project we present, a relay is activated in the presence of light. We can use it as...
The ZN414 is an uncommon integrated circuit currently used in the elaboration of very simple MW...
This circuit can be used to detect the signals from the previous circuit or from any radio...