We found this circuit in a 1980s American documentation. The operational amplifiers of the integrated circuit used can be common types in an experimental setup.
This circuit generates 50, 100 and 200 Hz signals from a 3.2768 MHz crystal and has outputs...
This oscillator has its frequency controlled by crystal and its frequency can be between 100 kHz...
This 3, 5, 6, 9 and 12 V power supply selected by a switch has a digital indicator of the selected...