1 pair of GE JG-5751 vintage tubes. These have the triple mica, shiny black plates and a slanted rectangle
getter.
Tested on a rebuilt and calibrated Heathkit TT-1A mutual conductance tester.
Tube 1 tests at 14001450 micromhos.
Tube 2 tests at 1400/1450 micromhos.
Reject point on the TT-1A for this tube is 780 micromhos with 1200 micromhos the average new tube reading.
No Gas, shorts, leaks or grid emissions. Strong life test.
The TT-1A is one of the best testers ever made. It's right up there with the best Triplett, Weston, RCA, high-end Hickok 539 series, and Western Electric testers.
The TT-1A can test at a relative high plate voltage with precision bias and a proper applied signal voltage to derive an active gm reading. Shorts and leakage tests are among the best, and a grid current test for power tubes will show as low as a 2 micro-amp leakage. A life test to estimate remaining useful service, independent plate buss, cathode buss, and grid buss are each selectable. The TT-1A has one of the largest, sag resistant, transformers of any tester.
If no box is shown they will ship in a generic white box or a vintage box from another manufacturer.
Satisfaction guaranteed. Any issues please contact me directly for a solution.
Free shipping on additional tubes purchased at the same time. Wait for a invoice or I can refund the difference.
Thanks for looking!