The RCA UV200 was one of the two initial valves sold by RCA. The maker was General Electric.
The UV200 was a soft valve, it had a low pressure argon gas filling. At the time soft valves were considered to be more sensitive for the role of signal detection. The filament is pure tungsten and thus this was a bright emitter. The other valve introduced at the same time was the UV201, a bright hard vacuum amplifier triode.
The electrode structure follows the pattern of the earlier VT-14
The brass base cap with printed lettering.
The UV200 box. The anode voltage for this valve is limited to 25 Volts whereas the UV201 has a maximum anode voltage of 100 Volts. The box still has the original RCA logo that dates it to the early 1920s.
The logo taken from the box.
Thanks to Joe Gruber for sending the images.
The envelope is mm in diameter and, excluding the UV base pins, is mm tall.
Reference: Joe Gruber. Type UV200 was first introduced in 1920. See also1920 adverts.