The 4X150A is a 150 watt, forced air cooled, power tetrode with a full rating frequency of 500 MHz that was first introduced by Eimac about 1947. The 4X150D is the same tube with a 26.5 volt filament. These tubes were later improved with 250 watt dissipation anodes and were redesignated the 7034/4X150A and 7035/4X150D. The first, second and third examples are made by Eimac with different markings and anode construction. The fourth example was made by Amperex and the fifth was made by RCA.
Length = 2.47" Diameter = 1.64"
Max voltage = 1250
Max current = 250 ma
Fil voltage = 6
Fil current = 2.6 amps