Semi-automatic keys like this "American Vibroplex" automatically produced rapid morse code dots by using a weighted pendulum to quickly make and break contact in the electrical circuit. The operator would make the dashes manually but could send much faster than with an ordinary key.
King & Company produced this key under license from a company that worked with Horace Martin, inventor of "Vibroplex" semi-automatic key.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.