(1) Tested Very Strong RCA 6BK5 Tube with Box Date Code CL RCA 6BK5 Tube (c)

(1) Tested 1949 RCA JRC 3Q4 Tube with Box Date Code 6-48 Mil Spec RCA 3Q4 Tube

(1) Tested RCA 12EM6 Tube with Box Date Code LR Diode Tetrode Tube

(1) Tested Very Strong RCA 6AF3 Tube with Box Date Code ND Half Wave Rectifier

(1) Tested RCA 6JU8A Tube with Box Date Code HD 6JU8 A Quadruple Diode Tube (a)

(1) Tested Strong RCA 12H6 Tube with Cleaver Brooks Box Date Code DE Diode (e)

(1) Tested Strong RCA 12H6 Tube with Cleaver Brooks Box Date Code DE Diode (a)

(1) Tested Strong RCA 12H6 Tube with Cleaver Brooks Box Date Code DE Diode (b)