Type 10 tube

[jim]

Picked up this Type 10 tube at a hamfest.  It is 100 years old.   I wonder how it sounds.   Jim

[PRR]

Cool!!

Appears to be a few years shy of 100.
https://www.radiomuseum.org/tubes/tube_10.html
First year    1925 -- Collector info
First Source (s)    Nov.1925

Particularly notable as the power tube in Bell Lab's experimental "home loudspeaker", and IIRC in RCA's commercial version.
https://www.radiomuseum.org/r/rca_9_25.html
Note the price: almost three times the price of a Model T.

At that, note that it runs 425V and 10k loading to get 1.6 Watts. That power was fine but the high voltage and many-many-turn winding were annoying. This leads to '43 and other tubes to make a whole Watt in 2k at 100V.