This piece originally ran in the July 2020 issue of EAA Sport Aviation magazine.
This telephone-telegraph dating back to World War I was designed to be used by ground troops in situations where telegraph and phone lines were in poor shape. It could be used as a field telephone, or, by using the buzzer, the key could send out an intermittent current and send Morse code via audio. It was manufactured in 1917 for the U.S. Signal Corps by the Stromberg-Carlson Telephone Manufacturing Co. of Rochester, New York.