I'm overhauling my 1941 Zenith this weekend

[tom.j.fla]

Hi, Here is another way to solve the 6X5 problem and keep the tube. If there is room above or below the chassis add a small transformer with a 6.3 volt 1 amp secondary and wire the 6X5 heater to the new transformer, do not ground the heater of the tube. Connect the cathode to one of the heater pins, that way you do not have the break down issues of that tube. I do that with all of my old Zenith radios with transformers and 6X5 or equ. tubes. hope this helps. All the best,Tom