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3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested
3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested

3x NOS National Electronics 6679 12AT7 Triple Mica Vacuum Tubes - TV7 Tested

$ 15.84

  • Brand: National
  • Country/Region of Manufacture: United States
  • Custom Bundle: No
  • MPN: 12AT7
  • Model: 6679
  • Modified Item: No
  • Seller Notes: “Tested NOS + on Dan Nelson Calibrated/Upgraded TV7 Digital Meter”
  • Type: Preamp Tubes

Description

Set of 3 NOS National Electronics 6679 12AT7 Vacuum Tubes - All Triple Mica, D Horseshoe Getters TEST RESULTS: Test NOS NO SHORTS, NO LEAKAGES, NO GAS Tube 1: Side 1: 116 = 5800 uMhos Transconductance(Gm) at 14.2 mA (Ia =Anode Plate Current) Side 2: 98 = 4900 uMhos Transconductance(Gm) at 11.0 mA (Ia =Anode Plate Current) Tube 2: Side 1: 108 = 5400 uMhos Transconductance(Gm) at 11.9 mA (Ia =Anode Plate Current) Side 2: 112 = 5600 uMhos Transconductance(Gm) at 12.9 mA (Ia =Anode Plate Current) Tube 3: Side 1: 107 = 5350 uMhos Transconductance(Gm) at 12.2 mA (Ia =Anode Plate Current) Side 2: 114 = 5700 uMhos Transconductance(Gm) at 13.0 mA (Ia =Anode Plate Current) For Reference: The Minimum good value for a 12AT7/6679 tube tested on all TV7 versions is 50/50 = 2,500/2,500 uMhos Gm which is about 65% of life. 'Bogey': Factory Data Sheet NOS when new is 80/80 = 4,000/4,000 (μ℧ ) uMhos Transconductance (Gm) at 3.7/3.7 mA Anode Plate Current Dissipation(+/- 10%) when tested at 100V. NOS is 110/110 = 5,500/5,500 (μ℧ ) uMhos Transconductance (Gm) at 10/10 mA Anode Plate Current Dissipation(+/- 10%) when tested at 250V. TV7's test at 150V. Our Test Set: Dan Nelson restored, upgraded and calibrated, TV7A/U with Digital Meter reading Transconductance in uMhos (Gm) and mA (Anode Plate Current). Many years of shipping Experience with FRAGILE Vacuum Tubes and Vintage Electronics.