The NR67 is a heptode variable μ mixer. The prototype was the M-OV X64. The old service code for the army ARH1 and after 1941 the designation was CV1280.
The Admiralty Pattern (specification) can be partly seen as W152.
The IO base pins.
Thanks to Mark Mallison for sending the images.
The classic envelope is 39 mm in diameter and, excluding the IO base pins, is 98 mm tall.
