This circuit is from a 1980s Motorola documentation. The circuit can be made with modern equivalent components. The original circuit is for the 115 Vac (110 V) grid and has two settings.
This circuit produces the sound of percussion such as blocks, drum, bell, etc. The frequency...
We found this oscillator in a publication from the 1960s. The frequency is around 600 Hz with the...
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...