Tested Matched Pair of IEC Mullard 19EA8 Tubes with Original Boxes.
Date Codes 4D. Made in Japan.
Tubes are closely matched for mutual conductance (Gm), date codes and internal structure - they are identical.
One box has some minor denting near the bottom tab.
Tested on a calibrated Hickok TV-10 military tube tester with no shorts and no leaks with the following results:
Gm Test = 3675-7250 and 3625-6750 micromhos
Minimum pass/good = 2700-4700
