11. The principle of operation is identical to that of a vacuum tube triode . 12. The design used triodes as phase inverters and drivers. 13. It has a total of about 450 tubes ( mostly dual triodes ). 14. Prior to WWII, almost all electronic amplifiers were triodes used without feedback. 15. Even better was a using a vacuum triode because it provided some amplification. 16. In addition to improving the triode vacuum valve, he developed directional loudspeakers. 17. Successful embodiments use the 6AS7G and the Russian 6C33-CB power triodes . 18. The transmitter was a buzzer, and the receiver an amplifier with triode . 19. His triode tube was tubular and had the capability of being double sided. 20. In 1918, Edwin Armstrong used only triodes when he invented the superheterodyne receiver.
