Hendrik van der Bijl

Sixty years ago this month, the PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS (IRE) included a classic paper on the theory of vacuum-tube amplifiers by Hendrik van der Bijl. At the time, he was in the laboratory of the Western Electric Company, the manufacturing unit of the American Telephone and Telegraph Company. His paper disclosed some of the important work dealing with the design of vacuum-tube triodes which he had accomplished since joining Western Electric in 1913. Van der Bijl pointed out that the vacuum tube deserved much of the credit for the “recent rather remarkable developments in the art of radio communication.” He outlined a theory based on a fundamental equation which gave the plate current as a function of plate and grid voltages and the structural parameters of the tube. He observed that it would be quite difficult to achieve satisfactory operation of electronic devices “without an explicit mathematical formulation of the operation.” Continue reading