Posts

Tuning the AM broadcast band

Image

Alignment part 2

Image
Did a full IF and RF alignment on the NC-98. It took 2 or 3 hours. All the repairs worked including the new trimmer capacitor. Its working excellent!

Alignment

Image
Starting on the alignment. Looks like the 455khz crystal has drifted to 452.6khz. The alignment will correct for the drift. The drift is normal, due to the age of the crystal. 65 years and counting

Bands

Image
Ran the National NC-98 for a couple hours. I am surprised by how well it is working. Pretty darn good sensitivity and selectivity. The only band that doesn't work well is the D band. That is the one where I had to replace the broken trimmer capacitor. A full alignment will be required, that's next in the list

Volume

Image
Repaired the volume pot by removing it and adding some Deoxit. Ran it back and forth a bunch and now it is fully functional

Bulbs

Image
Looked in my collection and found some NOS new old stock GE 47 bulbs. I replaced the two burned out ones in the NC-98. It looks beautiful!