Attached address is a schematic for your radio showing tube types. Those tubes were used in 1927 & 1928.
Norm
http://ww3.nostalgiaair.org/schematics/RCA/_RCA_1-32.gif
: I have a RCA Radiola model 41. No tubes or info. Does anyone know age and tube compliment? Set seems in pretty good shape. Speaker was changed though. Very heavy. Any info would be helpful.