Details
Used old stock tubular bulb octal beam power tube. Various brands.
NSN/FSN = 5960001005894, 5960001169927 (6V6GTY), 5960005534568, 5960005534569, 5960006174839, 5960006360533 (6V6GTY), 5960008248737 (6V6GTY), 5960008281857
HP/Agilent Number = 1923-0057
Signal Corps Number = VT-107A