Hendrik Johannes van der Bijl was born in Pretoria in 1887 and studied at Victoria College (today Stellenbosch University) before travelling to Germany to complete his doctorate in electrical engineering. While busy with his studies he unwittingly reinvented the thermionic valve that had first been developed by the American Lee de Forest in 1906. Van der Bijl’s research came to the attention of the American physicist Robert Millikan, who invited him to join his staff at the University of Chicago.
Van der Bijl was tasked with improving De Forest’s invention so that it could produce “continuous waves at even intensity” for long distance radio broadcasts. He subsequently fine-tuned the thermionic valve for wireless radio and produced a major scientific work, The Thermionic Vacuum Tube, which was considered fundamental to the study of radio. He also developed the first “scrambling” device for radio speech, and engineered the transmission of the human voice from New York to Paris (a distance of 4 800km) by short-wave wireless. For the next 20 years Van der Bijl’s improved thermionic valve became the standard design on which all modern broadcasting and television depended.
In 1920, at the age of 34 Van der Bijl was called back to South Africa by the then Prime Minister Jan Smuts to advise the government in the planning of South Africa’s industrial development. Van der Bijl oversaw the Iron and Steel Corporation’s first plant at Pretoria, but with the increased demand after World War II, 100 km2 was bought to build a large steel works and model town. The steel works began operating in 1947 and the town (Vanderbijlpark, named after dr Van der Bijl) was proclaimed in 1949.
An exhibition chock full of radios is currently on display at the National Museum and will run until May 2019. Make sure not to miss it!
Photo 1: dr Hendrik van der Bijl; photo credit: http://www.eskom.co.za/sites/heritage/Pages/Dr-Hendrik-van-der-Bijl-12.aspx