Sylvania 6K6 6K6GT Vacuum Tube Black Plate Chrome Dome / Silver Top NOS-Testing US-Made 5GM6 NOS It is dead quiet when

It is dead quiet when the preamp is muted and has excellent frequency response

These five RCA 5763 tubes tested as follows on our Paul Hart-calibrated TV7/U:

They are lightly microphonic and not suitable for environments with excessive vibration

(New US-made 6V6s typically test with plate current from the mid-teens to mid-30s with transconductance from 2300 micromhos or so

it tested as follows:

Sylvania 6K6 6K6GT Vacuum Tube Black Plate Chrome Dome / Silver Top NOS-Testing US-Made 5GM6 NOS It is dead quiet whenThis Sylvania 6K6GT tube was tested on our Maxi Matcher with 325 volts on the plates and a bias of 36 volts for shorts gas and transconductance. There were no shorts or gas. It measured 1680 micromhos and drew 19. 2 milliamps' plate current where new nominal is within one standard deviation of 1900. As I write, I am playing it my Mini Mite 2013 and it sounds great. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE