A high-power General Electric GL-861 triode. This vacuum tube, which measures 43 cm in length, was capable of up to 400 W of power at frequencies up to 20 MHz. The large size is dictated both by the relatively high power and the need for high-voltage isolation. A tube plate voltage of up to 3000V could be applied. While there has been no identified application directly in the nuclear industry, this tube was used to train engineering and physics students at the University of Toronto who graduated and played important roles in the industry. This model of electron tube was developed ~1935.
