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 simple circuit uses small speakers for both listening and speaking (microphone). The feeding is...
This little transmitter was found in a documentation about the transmitter being intended for the...
This remote-control transmitter for the 27 MHz band was found in the November 1960 Radio...