This circuit was found in an American documentation from 1975. The components of the time can no longer be found easily, but they can be tested equivalent.
MXT1665T-A Family from Microchip Brings the User Experience of Multi-Touch HMI into the VehicleCHANDLER,...
This circuit excites an LED, which will flash at a frequency adjusted by the trimpot. The other...
This 1 to 40 MHz amplifier is from a 1969 Motorola documentation. The components are of the time...