The P650 from Mazda is an early output triode. The design dates from 1929 and the P650 was obsolete by 1933.
The bright anode is a box with rounded ends and four side flanges. To each of the flanges is a support that projects down to a collar around the pinch stem. The collar is held in place by a nut and bolt that draws the ends of the collar together.
A better view of one of the side flanges.
The Mazda name and Type designation on the dome. A glass rod to the side holds the grid frame and filament tension springs.
The oxide coated filament and the corresponding tension springs.
The pinch components.
The lower ends of the filament and a closer view of the grid.
The balloon envelope is 58 mm in diameter, and excluding the B4 base pins, is 135 mm tall.
Reference: 1043. Type P650 was first introduced in 1929.