Sylvania 5U4 5U4GB Vacuum Tube Rectifier Black Plate Nine Eleven Tube One measured 64 while

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

It has flat

This new old stock-testing Svetlana 6550C / 6P27 perforated plate output tube was tested on our Maxi-Matcher 2 with 400 volts on the plates and a bias of -48 volts for shorts

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

Sylvania 5U4 5U4GB Vacuum Tube Rectifier Black Plate Nine Eleven Tube One measured 64 whileThis 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