The RS241 is a directly heated triode transmitting valve with a maximum anode dissipation of 15 Watts.
The gettering is both on the lower envelope and the dome. The lettering can be seen to be etched into the glass. The Telefunken name is visible. Given the construction with a glass support rod the top gettering could indicate that the valve was made using the Azide process.
This valve was made for the German military and carries the words RLM Eigentum and BAL716. The BAL716 identification shows it was made to the German Luftwaffe standard and inspected at that particular office. The RLM Eigentum indicated that the valve was the property of the Air Ministry of the Reich (1933-1945).
The anode side view together with the glass rod that supports the filament springs.
The reinforced anode seen through the Telefunken name. At the top the filament strands can be seen, some are intact but the middle one has broken.
Top supports for the grid and anode are also anchored into the glass rod at the side.
The glass support is held in place by a central rod fixed to the pinch.
The balloon envelope is 60 mm in diameter, and excluding the B4 base pins is 125 mm tall.
Reference: Data-sheet. Type RS241 was first introduced in 1931. See also1931 adverts.