(1) Tested Philco 6HB6 Tube with Box Date Code EXT Power Pentode Tube (b)

(1) Tested Philco 6ES5 Tube Date Code BBC High Mu Triode Tube

(1) Tested Raytheon 12EL6 Tube with Box Code IO4 Dual Diode High Mu Triode (a)

(1) Tested Raytheon 12EL6 Tube with Box Code IO4 Dual Diode High Mu Triode (c)

(1) Tested Philco Starlight 6AU8A Tube with Box Date Code 67-09 Triode Pentode

(1) Tested Sylvania 6KE8 Tube with Box Date Code bd DHB Triode Pentode Tube

(1) Tested Philco 6AU8A Tube with Box Date Code 6504 Triode Pentode

(1) Tested Sylvania 6MD8 Tube with Box Date Code fd AJD Medium Mu Triple Triode