Details
New old stock metal octal beam power tube. Various brands. Tubes marked 1622 are metal 6L6 tubes tested for proper operation in RCA theater amplifiers.
NSN/FSN = 5960001169929 (6L6Y), 5960002280053, 5960005576384
HP/Agilent Number = 1923-0034
Tektronix Number = 154-0087-00
Signal Corps Number = VT-115