1949 motorola table top

[dieseljeep]

Originally Posted by timmy

m5 is the ballast tube, does anyone know how many resistors are in this metal tube and what the values are because the schematic shows m5 at the line in as 37 ohms, or how to test to see if its good. the amount for an original ballast is just nuts at 85.00 i would rather use ceramic resistors to make this up if i had to.

Capacitance voltage drop is the way to go! I know it isn't authentic, but neither is a cluster of high wattage resistors. Plus, there is a cushioning effect on the inrush current.
The original ballast tube had some kind of an iron alloy wire, that would rust through. That's the reason, the new ballasts are glass, that are filled with, what I understand is nitrogen gas.