(1) Tested Delco 12V6GT Tube.
Date Code 5-13.
The 188 EIA code indicates that this tube was made by GE for Delco.
The wording on the base is partially worn away and faded - see photos.
This tube tests as NOS.
Tested on a calibrated Hickok TV-10 military tube tester and exhibiting no shorts or leaks with the following results:
Gm Test = 3800 micromhos
Minimum pass/good = 2320
NOS rating = 3480
~ Please view all 4 photos ~