Sylvania Number / Type 48 #48 Vacuum Tube Engraved / Stamped Base NOS-Testing October 17 2025 new in box 1X2 tubes

new in box 1X2 tubes tested to spec on our Paul Hart-calibrated TV7/U

These seven new old stock

These three US-made milspec VR-150 / VT-139 / 0D3A tubes tested to spec in our Hickok 800

It sounds very good with light surface noise and the occasional click and pop

It is also autographed by Mr

Sylvania Number / Type 48 #48 Vacuum Tube Engraved / Stamped Base NOS-Testing October 17 2025 new in box 1X2 tubesThis new old stock testing Sylvania engraved base type 48 tube was tested our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. It measured 80 where minimum (65%) is 50 and 100% is 77. It has a sheet getter; an anode radiator for cooler operation and longer tube life and a banded cross top mica spacer. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY