XTAL oscillator with fine tuning (CB22403E)

We found this circuit in an old English documentation. The integrated circuit is of a specific type of the time.

Digital Mixer (CB212E)
A stereo digital mixer using the 4053 is built as shown in figure bellow. The IC must be powered...
DC Motor Reversal with Transistors (2) (CB11602E)
I found this circuit in an English publication from 1989. This configuration can be mounted with...
TTL Circuit Protector (CB17135E)
The purpose of this circuit is to prevent TTL circuits from receiving a voltage greater than 5 V...