[AI2V]

By all means, upgrade the 36 tube to a 77 tube. It's pretty much the same circuit as the earlier version, the Model 19. The phenolic tube sockets are a source of nasty intermittents; if you can, replace those sockets; cleaning, pinching, and polishing them didn't do anything. .

With new sockets and the 77 upgrade, I've got a super radio that's a true "keeper"