RCA UV-202 Tube

RCA UV-202
The UV-202 tube was introduced in 1921, and was a larger, more powerful version of the UV-201.  It was widely used by amateurs in low-power transmitter applications, as in the following photo of 8BNY's transmitter, circa 1922.  Most had brass bases, but the last ones made had Bakelite bases.  The UV-202 was superceded by the UV-210 in 1925.  Shown below is the Cunningham version, the C-302.  
Ham Transmitter Using UV-202's
Cunningham C-302