Ken Hopkinson was the main designer of the display arrangements for the Ground Control of Interception (GCI) equipments together with Tutchings who was very innovative and made several very significant advances. He designed the receiver switching arrangements to make use of the capacity switch Bill Penley designed.  This allowed continuous switching between aerials and allowed multiple interceptions to be carried out independently with AMES type 7 (Air Ministry Experimental Station). This was the basis of the ‘Happidrome’.

He contributed papers to the Penley Radar Archives - see link below.