Matched Pair General Electric GE 12SL7 12SL7GT Vacuum Tubes Valves NOS NIB Philharmonia 100% is 77/77

100% is 77/77

Transconductance measured 24

new in box matched pair of Sylvania gray glass 7C5 tubse was tested on our Maxi-Matcher 2 with 400 volts on the plates and a bias of -36 volt for shorts

where minimum (65%) is 25/25 and 100% is 38

They measured 86/82

Matched Pair General Electric GE 12SL7 12SL7GT Vacuum Tubes Valves NOS NIB Philharmonia 100% is 77/77This new old stock, new in box matched pair of GE MANUFACTURED 12SL7 12SL7GT dual triodes was tested on our Pau Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 38 41 for Tube One and 42 41 for Tube Two (RCA LABELED) where minimum (65%) is 32 32. These tubes have copious bottom flashing, bottom, D getters, steel plates and steel suppost rods. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES.