Matched Pair Sylvania 7B7 Vacuum Tubes 6H6 Octal They may be Chinese

They may be Chinese

Transconductance was 1670 for Tube One and 1570 for Tube Two where new/nominal is within one standard deviation of 1900

milspec Sylvania 3Q5GT / JAN-CHS-3Q5GT / VT-221 tubes tested to spec on our Paul Hart-calibrated TV7/U

Support Rods: copper

Matched Pair Sylvania 7B7 Vacuum Tubes 6H6 Octal They may be ChineseThis nearly perfectly matched pair of Sylvania 7B7 tubes was tested on our Paul Hart calibrated TV7 for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 58 for Tube One and 59 for Tube Two where minimum (65%) is 43 and 100% is 66. They have mica snubbers for increased vibration resistance and lowered microphonics and great flashing. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT.