Description
Tube Type / Number: 5U4GB
Actual Brand*: Unknown
Printed Brand: Unknown
Quantity of Tubes: Date Matched Pair
Plate Construction: Black Smooth
Getter Construction: 2 Side []
Country of Manufacture: USA
Visible Date Codes: 188-5 1T & 188-5 LU
Lettering Condition: 10 Percent
Year Made:
Number of Mica Spacers: 2Sawblade I
Glass Coating: Clear
Engraved Base? No
Boxes Included? Multiple Boxes - NONE Original
Notes: 1 Tube Rattles, Tall Bottles
Gm Test Results: 62/62 & 65/62
Minimum Good Value: 40/40
NOS Test Value: 50/50
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.