This circuit was found in a 90s Popular Electronics. It produces a muted tone similar to that produced by a bell. The signal must be applied to an amplifier.
This circuit was published in Popular Electronics from the 90's. The components are common, as...
We found this receiver in an old English documentation. The JFET is commonly used and the bipolars can...
In this circuit, a unijunction transistor controls a multivibrator providing a rectangular signal...