Equivalent transistors can be used in this circuit for automotive applications in the 1980s. The frequency is given by the capacitor and the current of the lamp depends on the LM195 transistor.
Mouser has a huge list of sensors for the most diverse applications such as automation, IoT,...
This low-noise, low-drift amplifier was found in a 90's EDN. It can be implemented with modern...
This converter for the 150 MHz band was found in an American documentation. Transistors are...