The EM11 magic eye tuning indicator is German and dates from Summer 1939.
The target shows the classic circular design.
The pin design and layout is clearly visible.
The valve base is shown above and is this pattern was used in continental Europe but not in the UK. Philips made valves for this base, the naming convention matches the UK Mullard style. Mullard became a Philips subsidiary in the 1920s.
The wide glass tube envelope is 35 mm in diameter and, excluding the Footless base pins, is 73 mm tall.
Reference: Data-sheet. Type EM11 was first introduced in 1939. See also1939 adverts.
