AK Model 37 Condenser Block Rebuild

[Winky Dink]

After my post on my Atwater Kent Model 37 restoration I was asked about the filter condenser block, but at that time I hadn't done anything with it. Although the radio worked well, the experience of many restorers seemed to indicate that bad things might happen if 85-year-old papers caps are left alone. So, I decided to have a go at it and post some photos showing what lurks beneath the tar.

The Model 37 power unit comes in two separate cases; one for the transformer and one for the filter condensers and chokes. Previously I had only replaced the external wiring.



To preserve the original crinkle finish, I did minimal heating to the outside of the case. I expected that the case to be tightly packed with only a small amount of tar, but this was different. I removed one and a half pounds of tar just to expose the components and wiring. There's a metal plate dividing the case into two sections. One section has two coils; the other has one coil and four paper condensers. To be sure that I would be able to rebuild it properly, I wanted to keep the whole assembly intact, but I anticipated breaking some of the connections, so I color-coded them before removal.



After softening the remaining half-pound of tar, I pulled out the filter condenser assembly, part number 13315. There are two versions of part 13315--early and late. This is the early type. The late type is the same except for the addition of one more condenser.



I made a color-coded a schematic of the assembly to help me reassemble the unit. Continuity and resistance readings through all three coils are good, so the rest of this job should be a piece of cake!...I hope.