Reference tube is tested first then the tube listed for sale.
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See photos comes as is no returns
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I use my Etracer curve tracer in tandem with research and experience. One of the only other modern testing devices at this level would be the Amplitrex AT1000, but even that unit cannot develop full spectrum graphical analysis the way the Etracer can.
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Full mutual conductance test, strong pristine nos pair: 110/110 ~ 109/110 % gm (65) + leak/short/gas/life/sound checks. 12at7 ecc81 ecc801s e81cc 12at7wa B739 B309 6211 cv4024 cv455 a2900 6060 6201 5965 12ay7 12av7.
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These were made for industrial use, and can take long periods in full cutoff without changes in characteristics. Large Gray Ladder Plates, O Getter. Tube 1 Gm 9900/9700.
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Mullard made for GE. Vacuum Tube. sections of a single tube. Within 3% I consider to be 'Balanced'. Tested at 92/90. Code = B0T4. Clean tubes will radiate heat better & operate cooler. Test results may differ between various testers for many reasons such as technical design, aging components, etc.
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I test all tubes thoroughly and with great care. I test to the best of my ability, and I report all results honestly.
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I use my Etracer curve tracer in tandem with research and experience. One of the only other modern testing devices at this level would be the Amplitrex AT1000, but even that unit cannot develop full spectrum graphical analysis the way the Etracer can.
eBay