Variant Globe. Condition Tested as NOS. VT-51 are similar to Type 10 VT-25 but have a higher amplification factor they are close but not considered a direct plug and play sub. Getter Side Foil Square.
Item Tag: VT-51
NOS GE VT-51 841 GLOBE TUBE DATED 1937 TESTED AT 135%
GE VT-51 841 Globe Tube. Tube #1 tests at 52 Approx 135%. This Tube Tests 106% on Dan Nelson calibrted TV/7 Tube Tester. Years ago, I put away a bunch of great Tubes.