Thanks to matt_s78mn, I have almost a complete set of NOS RCA Radiotron period tubes for this set
I'm only missing a UX280. Also, one output tube is a 45 while the other is a UX245. I don't think there's any difference though.
One thing I did notice right away is the filament glow. These old 224s light up immediately with a bright white light. Later 24As have the typical slowly brightening, orange glow. I guess that's what the A means - controlled, improved filament glow ?
The UX245 required some assembly. I couldn't find any evidence that the leads were ever soldered. Maybe some sloppy quality control
Once I put a base on, it tested like new
Speaking of quality control - I came across this tube
