Looks to me like either a 5R4GY or 5U4G, though most of my 5U4G's have ribbing on the plates, not all. That would be my best guess.
If he looks really good at the glass at the right angle he should find the marking of what the tube is. I have found that on many tubes, even if the markings are rubbed off from age or cleaning they can still be faintly found under the right light at the right angle. Just something to try if he doesn't mind looking.
If he looks really good at the glass at the right angle he should find the marking of what the tube is. I have found that on many tubes, even if the markings are rubbed off from age or cleaning they can still be faintly found under the right light at the right angle. Just something to try if he doesn't mind looking.
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Plates are too short for any 5R/U4 I've seen.
My guess is a Type 80 or 5Y3G. Look at the pic on the right:
http://dmradios.com/280.jpg
Cheers!
My guess is a Type 80 or 5Y3G. Look at the pic on the right:
http://dmradios.com/280.jpg
Cheers!
Hmmm... I may stand corrected. To me though it is a bit hard to tell at that angle if it is a ST-16 or close up of a ST-14 bottle. If he can provide a shot from straight on that would be better.


Looks suspiciously like a UX-4 4 pin base to me, (is it?) and the plate structure looks like an 80 to me as well.
It looks a little cloudy down near the base. (mercury) And the plate structure is exactly the same as a NOS RCA type 83 complete with the two supporting rods up the middle.
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If he looks really good at the glass at the right angle he should find the marking of what the tube is. I have found that on many tubes, even if the markings are rubbed off from age or cleaning they can still be faintly found under the right light at the right angle. Just something to try if he doesn't mind looking.
Try heavy breathing (on the glass). Fogging up the glass sometimes reveals the markings. A trick that Stan at the tube center showed me....
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