When did the Royal Navy begin testing radar capabilities?
Short answerOfficially around 1937, with shipboard installation and experimental work already beginning in 1936.
NotesThe defensible official starting point is 1937, while less formal work began earlier. HMS Saltburn received an early set in October 1936 for testing in 1937, and the developing Type 79 family soon appeared in the fleet, showing that shipboard radar work was underway before the commonly cited late-1930s fit dates.