Found in a 90’s Radio Electronics, this circuit uses a component from the time, difficult to find today. It generates 12 tones in different octaves.
This 100 Hz filter was found in the August 1993 issue of Electronics Now. The components can be...
Found in an Elektor from the 90s, this circuit can be powered directly by the power grid. The...
The power supply for this circuit found in a QST magazine is given in the previous circuit. The...