The Type 10 is described by RCA as an audio power amplifier. At 425 Volts on the anode a single triode can produce 1.6 Watts of output.
It is believed that the design first appeared in 1925.
The Type designation 10 within an octagon border.
The RCA logo and the location pip on the base cap as the UX4 is bayonet mounting. That also explains the solid pins as the springs are in the valve-holder.
The box anode and glass rod to the side holding the control grid supports and the filament tension spring.
Face view showing the pair of tensioning springs and one wire of the grid.
The hooks on the tension springs are empty s the filament has failed.
The classic envelope is 54 mm in diameter, and excluding the UX4 base pins is 117 mm tall.
Reference: Data-sheet. Type 10 was first introduced in 1925. See also1925 adverts.
