National NC-98 restoration

The first fire up. Its working! Still a few small issues. The face plate bulbs are burned out, and the volume pot only works about half way. So excited to hear this 1955 radio come to life!

We've got glow!

Breaking in the dim bulb tester with the NC-98.

I ended up replacing 4 of the 9 tubes.

This radio uses two 6BD6 tubes. Both tested weak. These tubes are fairly rare, and believe it or not I didn't have a single one in my collection. However I found that the 5749 tube is a substitute, and I had several of those. The two I picked out measured excellent and above spec.

Testing the tubes. Turns out that the original tubes were all Sylvania. So all of the tubes have been replaced at some point...

All capacitors replaced!

Found where the disconnected capacitor went, and I replaced it.

Got the last electrolytic capacitor replaced. The new one is about 1/10th the size.

Frayed wires in the plug looking a little iffy... I went ahead and fully disassembled it, cleaned everything and fixed the frayed wires.

Got the power supply section recapped. Three 22uf caps.

Found and installed a replacement trimmer capacitor. I found it on a junk parts chassis from the same vintage. Circa 1955.

Got another radio on the bench. National NC-98. Initial inspection... Overall its clean and not corroded. Lots of dust. Wrong rectifier tube. Rectifier tube glass feels loose, and may be broken. All but 3 if the tubes look to be original Tung-Sol. Bottom plate missing. All original capacitors. One capacitor disconnected and has yellow electrical tape on it. One trimmer capacitor is completely broken in half and will need to be replaced. It'll be a challenge but I think I can fix it