11. The Champ had only one power tube . 12. The highest-power tube currently available is the Eimac, a forced water-cooled power tetrode capable of dissipating 2.5 megawatts. 13. For the Epitaph tour, he switched to using Engl Invaders that are modified to use 6L6 power tube . 14. An alternative solution for power applications is the beam tetrode or " beam power tube ", discussed below. 15. Although the envelope is typically glass, power tubes often use ceramics, and military tubes often use glass-lined metal. 16. Later developments produced beam power tubes which were capable of high-power output at frequencies extending into the UHF region. 17. They use two 5881 / 6L6GC power tubes , a GZ34 tube rectifier and are rated at roughly 40 watts. 18. The operating lifetime of a triode is about 2000 hours for small tubes and 10, 000 hours for power tubes . 19. Instead of the usual EL84 power tubes , the Valpreaux employs either two or four of the semi-obscure "'6973 "'power tube. 20. Instead of the usual EL84 power tubes, the Valpreaux employs either two or four of the semi-obscure "'6973 "'power tube .
