RCA Radiotron Number / Type 56 Vacuum Tube Globe Balloon Style Engraved / Stamped Base NOS-Testing Postcards From These four US-made belll-plate number

These four US-made belll-plate number / type 77 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

These Ken-Rad-MANUFACTURED

The bottle was already tightly-affixed to the base

Tube One measured 42 while Tube Two measured 45 where minimum (65%) is 46 and 100% is 71

RCA Radiotron Number / Type 56 Vacuum Tube Globe Balloon Style Engraved / Stamped Base NOS-Testing Postcards From These four US-made belll-plate numberThis new old stock TESTING RCA Radiotron type 56 triode was tested on our Paul Hart calibrated TV7 for shorts, gas and transconductance. There were no shorts or gas. It measured an outstanding 82 where minimum (65%) is 37 and 100% is 57. It has a thin, rounded rectangle top mica spacer; rounded dark gray plates; a dimple, sheet getter; excellent flashing and a sharply engraved base. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE