(1) Tested Balanced RCA 6SN7GTB Tube.
Short bottle envelope with a thin base.
Date Code 513 (March of 1955).
Balanced mutual conductance (Gm) with a side square D getter and 4 hole black staggered plates.
Tested on a calibrated Hickok TV-10 military tube tester with no shorts and no leaks with the following results:
Gm Test = 2750-2750 micromhos
Minimum pass/good = 1650-1650
Also performance tested in-circuit through a Class A amplifier with no microphonics detected.
~ Please view all 5 photos ~
