Found in a 90’s 303 Circuits, this circuit uses components that are still common and has a common LED as indicator.
This circuit was found in an English magazine from 1978, but it can be easily assembled today,...
It can be obtained from Mouser Electronics the new MAX14871 Maxim consisting of a full-wave...
This transmitter has the frequency that depends on the crystal. We find it in a 1980s...