Wave Transmitter

The Wave Transmitter was a combined radio transmitter and receiver built by the Brazilian priest and inventor Roberto Landell de Moura, capable of sending audio over both radio waves and modulated light in a manner similar to a photophone. Landell began wireless experiments in the mid-1890s, received a Brazilian patent for a related photophone device in 1901, and traveled to the United States that year to seek patent protection, receiving United States Patent No. 771917 for the Wave Transmitter in 1904. The device used an electromechanical microphone paired with what he called a phonetic interrupter, which converted sound vibrations into electrical sparks or flashes of light that could be received and converted back into audio, and American technicians who evaluated his work at the time judged his wireless system superior to what had already been developed elsewhere. Landell returned to Brazil in late 1904 in significant debt and failed to win government support for further demonstrations, partly because of skepticism toward his additional claims about interplanetary communication, and his work remained largely forgotten in Brazil and abroad for decades afterward.