The 845 or VT-43 is a general purpose, 100 watt, triode with a mu of 5.3 that was designed to be an audio amplifier tube. They were first available in 1928 as the UV845. The first example was made by RCA and the second example was made by GE. These tubes were made with the designation SE-3945 for the Navy. De Forest made their version designated 545 and United made a version the 845W. The third example is marked as an Amperex tube, but is a re-marked 845W made by United.
Length = 7.87" Diameter = 2.31"
Max voltage = 1250
Max current = 150
Fil voltage = 10
Fil current = 3.25