Matched Pair General Electric GE 6BL7 6BL7GTA Vacuum Tubes NOS NIB Matched Pair 1622 Wish I knew who actually

Wish I knew who actually made them

Detector and First Audio 12AV6

new in box matched pair of RCA 6GU7 dual triodes was tested on our Jackson 648 Mutual Conductance tester for shorts

Transconductance readings are indicated on the tops of the tubes

These end links appear to be made of stainless steel and rose gold or copper

Matched Pair General Electric GE 6BL7 6BL7GTA Vacuum Tubes NOS NIB Matched Pair 1622 Wish I knew who actuallyThis new old stock, new in box (For Tube One) matched pair of GE MANUFACTURED 6BL7GTA dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 49 50 for Tube One and 50 50 for Tube Two (RCA LABELED). where minimum (65%) is 25 25 and 100% is 38. 5 38. 5. They have O getters; copper support rods; great flashing; stout black plates; anode radiators for cooler