This transistorized siren was found in the patent section of Radio Electronics magazine from March 1968. The circuit uses components from the time and has a very elaborate configuration.
This circuit was found in the November 1992 issue of Radio Electronics magazine. It uses...
This multivibrator has its frequency controlled by a crystal. Other frequencies can be generated by...
We found this preamplifier circuit with high input resistance, on the order of 30 M ohms, in an...