This circuit uses a capacitor that depends on the frequency of the crystal. We found it in a 1967 documentation. The maximum frequency is around 100 kHz.
The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue...
According to the consulted American publication of the 1980s, a zener diode can be used for DC...
This circuit originally appeared in a publication of 1997. With the changes, the circuit can be...