NIB 1953 Sylvania USA 6BL7GT Black Plate Top [] Get 3 Mica Vacuum Tube 73/108%

Tube Type / Number: 6BL7GT
Actual Brand*: Sylvania
Printed Brand: Sylvania
Quantity of Tubes: Single
Plate Construction: Black
Getter Construction: Top []
Country of Manufacture: USA
Visible Date Codes: H3E 426
Lettering Condition: 100 Percent
Year Made: 1953
Mica Spacers: 3
Smoked Glass? No
Engraved Base? No
Boxes Included? 1 Box - Original
Notes: Crooked Mica, Poor Getter Flashing

** If the actual brand does not match the printed brand, this is perfectly normal. This is because many manufacturers made tubes for each other and also printed various amplifier and radio brand names on tubes destined for those companies. The actual brand was determined by the EIA codes printed on the tube. In some cases, the brand will be determined by the tube's construction **

General Mutual Transconductance (Gm) Test Results:

30/47 Where the Minimum is: 25/25 and the NOS value is: 41/41
or
73/108% of what a NOS tube should test where the Minimum "good" value is 65%

Tests NOS?: No
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.