Found in the November 1999 issue of Electronics Now magazine, this circuit generates a 6.67 Hz signal from a 4.1952 Hz crystal.
This stage was found in a 1964 Electronic Design. The transistors are of the time and the shape of...
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...
This circuit, which is present in other points of this website, was found in a 90s Hands On...