Italian Sylvania 12SN7 12SN7GTA Vacuum Tube NOS NIB 8BQ5 Nonal new in box Zenith 6GV5

new in box Zenith 6GV5 tube tested to spec on our Paul Hart-calibrated TV7/U

They measured (from left to right

They measured 52

This CD plays fine

Transconductance: 2200 micromhos Transconductance: 2270 micromhos

Italian Sylvania 12SN7 12SN7GTA Vacuum Tube NOS NIB 8BQ5 Nonal new in box Zenith 6GV5This new old stock, new in box Italian Sylvania 12SN7GTA dual triode was tested on our Hickok 600A for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured a perfectly balanced 2700 2700 micromhos. (New 6SN7s typically test within a standard deviation of 2600 micromhos; minimum (65%) is 1690). It has copper support rods; staggered gray plates; copious flashing and a large, side D getter. I have played it in one of