Using a 4046 PLL we found this circuit in the December 1989 issue of Radio Electronics magazine. The circuit operates at 220kHz, but this frequency can be changed by changing C3.
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...
This circuit uses a piezoelectric transducer to produce sounds like a buzzer. Frequency is...
Guitar preamp (CB22146E) Found in an English publication from 1989, this circuit uses a still...