Sylvania 5U4 5U4GB Vacuum Tube Rectifier Black Plate Nine Eleven Transconductance measured 72 for Tube

Transconductance measured 72 for Tube One and 76 for Tube Two where minimum (65%) is 58

Tube One measured 64 while Tube Two measured 66 where minimum (65%) is 46 and 100% is 71

new in box Realistic (Radio Shack) Gold Clad Japanese-made 6AU6A tubes tested to spec on our Paul Hart-calibrated TV7/U: 75

new in box GE 22JR6 tubes tested to spec on our on our Jackson 648

a top slanted-D getter and L1E -- or IJI -- date codes

Sylvania 5U4 5U4GB Vacuum Tube Rectifier Black Plate Nine Eleven Transconductance measured 72 for TubeThis black plate Sylvania 5U4GB rectifier tube tested 52 48 in Sections One and Two, respectively, on our Paul Hart calibrated TV7 U where minimum (65%) is 40 40 and 100% is 62 62. It has a top O getter; a crenelated top mica spacer; black plates and jd AED date codes. THIS TUBE'S CENTERING PIN IS MISSING AND IT HAS BEEN MARKED FOR SAFE AND EASY INSERTION. THERE IS A CLOSE UP PHOTO OF THE BASE TO SERVE AS A REMINDER. WE HAVE SCORES OF THOUSANDS OF