Cyril Frank Elwell (August 20, 1884 – February 11, 1963) was an Australian-born[1] American inventor and pioneer in development of radio.

[4] Elwell designed a large transformer for electric arc furnace reduction of iron ore; this became the topic of his thesis.

In 1908 he switched interests to wireless communication after investigating a system for voice transmission by spark gap transmitter invented by Francis Joseph McCarty (1888-1906) in 1902.

The apparatus Elwell had evaluated proved unsuitable, but he knew of the Poulsen arc converter, which differed from the spark gap in producing a continuous wave.

Equipment and technique rapidly improved and by 1911 Federal Telegraph was prepared to bid on contracts to provide Navy communication to Hawaii.