Radio Corporation of America
No introduction needed. Formed in 1919, the giant of the radio tube world has perhaps the most number of variants of all manufacturers. My focus will be to add something new to the puzzle of figuring out these high quality tubes.
One of several manufacturers 'contracted' to make tubes for RCA branding.
Some of the same companies made tubes for other brands: notably Cunningham / Audiotron Sales Co.
Detectors - RCA 200 series tubes
(21) variants identified
Amplifiers - RCA 201 series tubes
RCA Tube Litigation