The first true walkie-talkie was built by Don Hings in 1937. It was designed as a portable field radio that was also known as a wireless set or “pack set”. The term "walkie-talkie" (sometimes "talkie-walkie") was coined by journalists reporting on these new inventions during the war.
Until the war broke out in 1939, they were ignored for the most part by the world at large. But after the war began, they suddenly became a vital military technology. CM&S loaned Hings to the Department of National Defence and the National Research Council in Ottawa to help redevelop his invention for use in battle.
After a few years of R&D, Hings' had developed his portable radios into a variety of models for the army. The Model C-58 Pack Set was a tremendously successful design, both in performance and production, with tens of thousands of units being built and shipped overseas. Variants were designed for both European and tropical theatres, along with vehicle- and tank-mounted versions.
Some of the innovations in the C-58 Walkie-Talkie were variable antennas and power supplies for maximum versatility in battle, a voice scrambler to prevent eavesdropping, and a special filter that eliminated battle noises from the transmission. All in a lightweight, high performance, durable package without any moving parts, and extreme simplicity of operation, as the military demanded.