This 1/2 hertz high selectivity filter was found in the December 1990 issue of Radio Electronics magazine. The source must be symmetrical. The capacitors can be changed for other frequencies.
We found this oscillator in a 1979 amateur radio documentation. The circuit can use transistors like the...
This circuit is nothing more than a powerful audio oscillator or buzzer with a power transistor. The...
This circuit is from a Radio Electronics from February 1970. The circuit has a light bulb as an...