The 2103 double pentode is for audio amplification as a class A push-pull pair.
The anode to anode load should be 24k Ohms and the output is 0.6 Watts. The suppressor grid is connected to the mid point of the filament and the screen grids are connected together internally.
Two separate pentode sections are contained in the envelope. Both with bright box anodes.
The space above the pinch contains the straps that interconnect the two sections.
The top mica showing the two sections and central filament support.
At an angle, one can see the filament wire and the grids.
A close-up of the space beneath the anodes. The notched grid supports being prominent.
Another close-up, this time the paralleling straps and the central filament support are revealed.
The classic envelope is 38 mm in diameter, and excluding the UX7 base pins is 92 mm tall.
Reference: 1043. Type 2103 was first introduced in 1935. See also1935 adverts.