NOS In Box Matched Pair GE USA 12B4A Black Plate Top O Get Vacuum Tubes 100+%

Tube Type / Number: 12B4A
Actual Brand*: GE
Printed Brand: GE
Quantity of Tubes: Matched Pair
Plate Construction: Black
Getter Construction: Top O
Country of Manufacture: USA
Visible Date Codes: CI 188-5
Lettering Condition: 50 Percent
Year Made:
Mica Spacers: 2
Smoked Glass? No
Engraved Base? No
Boxes Included? 2 Boxes - ONE Original, ONE NOT Original
Notes:

Gm Test Results: 52 & 54
Minimum Good Value: 32
NOS Test Value: 52
Life Calculation: 100+% (where 65% = fail)

Tests as NOS?: Yes
True NOS?*: No

** Please note, many tubes will test NOS but will actually have a few hours of use on them. A truly NOS tube will have excellent getter flashing condition, no dirt/grime, usually in the original box, and no filament deposits. If a tube is listed  as "tests NOS" but is listed as "not True NOS" please expect the tube to have a small amount of use *

All tubes have been tested using only the best tube testers. We have a large fleet of tube testers, and every single one of them has been calibrated within the last year by industry experts. We mainly use the Hickok TV-7D/U, but occasionally we may use a Hickok 539, 533A, or 600A.