This simple Morse Code oscillator was found in a 1980s American documentation. The power supply should be powered with 5V and the integrated can be the 7400.
This circuit is from a 1970 General Electric documentation. It can be found with variations on this...
This circuit was found in a General Electric documentation from 1970. It is used in an optical...
This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and...