The RL12P50 is a transmitting pentode. The 12 indicates the heater voltage, the P is for pentode and the 50 is the maximum dissipation. The anode and suppressor grid connections are brought out to top caps. As an HF Class C power amplifier the maximum output was of the order of 85 Watts. Full ratings are for a maximum frequency of 24 MHz.
The designation is a pentode and the suppressor grid wires can be seen through the notch in the outer anode wall.
The feint etched lettering on the right is probably the quality acceptance information of the German state.
The side contact base pins with moulded key on the cap to ensure correct orientation.
The anode on the left and suppressor grid connection on the right.
Looking directly at the base.
The wide glass tube envelope is 45 mm in diameter and, excluding the base pins, is 102 mm tall.
Reference: Data-sheet. Type RL12P50 was first introduced in 1941. See also1941 adverts.
