12-30-2014, 03:25 PM
You have more concerns than 5x4/5u4 substitution. You can check that out with a tube manual or Duncan Amp web site.
Your 37 has the philco wire problem, hidden caps in the bakelite and IF cans and bad electrolytics that may have been wired wrong.
I would check the continuity of all major parts, power transformer, output transformer, IF's, all osc. and ant coils. Then I would check resistors for opens and high values. Then I would replace all caps. Then I would make sure wiring is safe.
Much later, when you are ready to power up, I would use a variac or a dim bulb device and heavily fuse the power transformer. These things are hard to get and expensive.
Good luck, millievolt
Your 37 has the philco wire problem, hidden caps in the bakelite and IF cans and bad electrolytics that may have been wired wrong.
I would check the continuity of all major parts, power transformer, output transformer, IF's, all osc. and ant coils. Then I would check resistors for opens and high values. Then I would replace all caps. Then I would make sure wiring is safe.
Much later, when you are ready to power up, I would use a variac or a dim bulb device and heavily fuse the power transformer. These things are hard to get and expensive.
Good luck, millievolt
