The RS237 is a power triode made for the German war effort in the mid to late 1930s. They were used originally in airbourne transmitters. One internet source quots them being used in a Heinkel HE-111 bomber.
The anode dissipation is 100 Watts and while the anode seems to be perforated in mesh fashion it is in fact dimpled and not pierced in this example.
Looking at the filament under a glass it appears to be thoriated tungsten wire formed into a pair of inverted V's.
The assembly is rugged and clearly professional. The support structure is clamped to the pinch stem with a nut and bolt to tighten the band. The top insulator is ceramic for high voltage use.
The dimpled anode is carburised for better radiation.
Here the detail of the anode can be clearly seen. On the broad face is a pair of diagonal webs for increased rigidity. The grid is shaped and made of robust wire, this would be required in a transmitter valve that operates in Class C and is required to pass grid current and thus dissipate some power.The supporting rods form a cross bracing. These features all point to a service life in mobile or airborne use.
The base pins are held in ceramic and the fixing into the holder is with a bayonet fixing. This also forms a good locking connection that is suitable for an operating environment where a vibration hazard exists.
This valve was donated by Roger Newbury. He had kept it safe for over two decades and then offered it to the museum.
See alsoPT15 for a classic UK airborne transmitter valve. The RS237 has three times the anode dissipation.
The wide glass tube envelope is 51 mm in diameter, and excluding the base pins is 175 mm tall.
