Details
Used old stock 9 pin miniature twin triode. RCA brand. ECC83 is the European designation.
NSN/FSN = 5960000812559, 5960001667664, 5960004859160, 5960005093055, 5960005397913, 5960006178559, 5960006562447, 5960007123983, 5960007812814, 5960007934377, 5960008412352, 5960008920825
HP/Agilent Number = 1932-0030, 1932-0051, 1932-0054, 1932-0056, 1932-0065, 5080-0021, 5080-7330, 5080-7340, 5080-7341, 5080-7342, 5080-7362
Tektronix Number = 154-0043-00