This dual-tuned 60 Hz oscillator was found in the Radio Experimenter Special projects of 1993. The circuit has the timing ranges given by C1 which can be changed.
8E) This siren was found in a 1989 documentation. It uses only transistors and includes two power...
We found this circuit, which appears with variations on this site, in a European documentation from the...
The operational amplifier used in this configuration is of an uncommon type today. The circuit can be...