Believe it or not, you can still get NOS (New Old Stock) tubes through Radio
Shack. I recently bought a backup set of tubes for my R.L. Drake SW-4A, which I
purchased new in 1975. I gave the list to the salesperson at Radio Shack, and
they called me in two weeks, with the complete list ready for pickup. They all
came in Realistic tube boxes, and appeared to be new. Funny thing is, I have
never replaced a tube in this receiver, and it still performs like the day I
bought it! Now that says something about well built old tube receivers. Good
DXing to you, Gary