(1) Tested GE 6KA8 Tube with Box Great Britain Date Code HI Triode Pentode

(1) Tested Ford Philco 6KA8 Tube with Box Japan Date Code 2L Triode Pentode (a)

(1) Tested RCA 6CX8 Tube with Box Date Code CR Medium Mu Triode Pentode Tube

(1) Tested RCA 6KA8 Tube with Box Date Code GJ Triode Pentode Tube

(1) Tested Sylvania 6GH8A Tube with Box Date Code ae Triode Sharp Cutoff Pentode

(1) Tested Sylvania 6CU8 Tube with Box Date Code am YAD Triode Pentode Tube

(1) Tested Sylvania 17JZ8 Tube with Box Date Code dg AOR Triode Beam Pentode

(1) Tested Westinghouse 6KA8 Tube with Box Date Code 67-43 Triode Pentode Tube