(1) Tested Strong RCA 6CL6 Tube Date Code EK RCA 6CL6 Power Pentode Tube (d)

(1) Tested RCA 6CL6 Tube Date Code 3-13 RCA 6CL6 Power Pentode Tube

(1) Tested RCA 6CL6 Tube Date Code EK RCA 6CL6 Power Pentode Tube (a)

(1) Tested Strong RCA 6CL6 Tube Date Code EK RCA 6CL6 Power Pentode Tube (c)

(1) Tested Strong RCA 6CL6 Tube Date Code EK RCA 6CL6 Power Pentode Tube (b)

(1) Tested GE 6CL6 Tube Date Code 61-35 General Electric Power Pentode Tube (a)

(1) Tested RCA 6CU5 with Box Date Code NF Black Plate Beam Power Pentode Tube

(1) Tested RCA 6CU5 with Box Date Code CV Black Plate Beam Power Pentode Tube