The 6155 or QY3-125 is a 125 watt tetrode designed to be an all glass replacement for the 4-125A/4D21 The first example is marked RCA but made in Germany. The second example was made by Mullard. The 6155U made by Amperex is very similar.
Length = 4.75" Diameter = 2.25"
Max voltage = 3000
Max current = 220 ma
Fil voltage = 5
Fil current = 6.5 amps GOTO INDEX