This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
This circuit was obtained from an English magazine from 1977. It is a toy musical instrument that...
April 11, 2016 - Mouser Electronics, Inc. is pleased to announce the availability of the new ...
Found on Popular Electronics this circuit has variations found throughout this site and section....