NOS NIB Matched Pair Vintage Tung-Sol USA 1S4 [DL1] Transoceanic Vacuum Tubes

Tube Type / Number: 1S4 [DL1]
Actual Brand*: Vintage Tung-Sol
Printed Brand: Tung-Sol
Quantity of Tubes: Matched Pair
Plate Construction: Silver Smooth
Getter Construction: Top Fat D
Country of Manufacture: USA
Visible Date Codes: 322752 & 322652
Lettering Condition: 75 Percent
Year Made:
Mica Spacers: 2
Smoked Glass? No
Engraved Base? No
Boxes Included? 2 Boxes - Both Original
Notes: For Zenith Transoceanic

Gm Test Results: 55 & 58
Minimum Good Value: 36
NOS Test Value: 58
Life Calculation: 100+% (where 65% = fail)

Tests as NOS?: Yes
True NOS?*: Yes

** 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.