This circuit for generating precise reference signals was found in the April 1973 issue of Radio Electronics magazine. The circuit generates 100 kHz signals according to the crystal used.
For those who like experimental circuits, here is a sequential flasher system with LEDs, which can be...
This circuit was found in an ancient American documentation. The integrated circuit is of the time...
This circuit was found in a 1977 Radio Shack documentation. The circuit is tuned to 1.4 kHz, but...