So it looks like it was probably part of the Beam Approach equipment, normally an extension, or development, of the "Lorenz" equipment in British aircraft, mainly bombers, with the external " towel rail" antenna, as seen on,, for example, Lancaster and Halifax aircraft.
This was an early version of ILS ( Instrument Landing System ), and involved a basic radio transmitted signal to the Beam Approach receiver, which guided the aircraft on it's final approach to the runway heading.