What are the specific ways that a type 1614 vacuum tube differs from a type 6L6?

Question

Both the 6L6 and the 1614 were beam power tetrodes in a metal envelope with an octal base. The 6L6 was the original version of the beam power tetrode, and was announced in the late 1930's. The 1614 seems to have been developed during WW2. The general answer seems to be that the 1614 was a more rugged version of the 6L6, intended for military use. I want to know exactly what are the changes that were made to the internal structure to accomplish this rugged type 1614. Also, changes in specifications, such as plate dissipation, maximum voltages, etc.

Answer 1

Read the text at the bottom of this site. It looks like the 1614 has higher power dissipation and was intended for class C rf amplification.

http://www.tubecad.com/december2000/page19.html