This coin is approximately 2 inches in diameter.

Royal Air Force Digby otherwise known as RAF Digby is a Royal Air Force station located near Scopwick and 11.6 mi (18.7 km) south east of Lincoln, in Lincolnshire, England. The station is home to the tri-service Joint Service Signals Organisation, part of the Joint Forces Intelligence Group of Joint Forces Command.^[3] Other units include the RAF Aerial Erector School, No. 54 Signals Unit and No. 591 Signals Unit.

Formerly an RAF training and fighter airfield, it is one of the country's older Royal Air Force stations, predated only by RAF Northolt, which is the oldest and predates the Royal Air Force by three years, having opened in 1915. Flying at Digby ceased in 1953.

 (REF: Wikipedia)

NSA’S QUIET PRESENCE AT A BASE IN ENGLAND’S COUNTRYSIDE REVEALED IN SNOWDEN DOCUMENTS

From a countryside compound in Lincolnshire, British and American spies eavesdropped on the Arab Spring and directed drones in the Middle East.

The spies were part of a group known as Joint Service Signal Unit Digby, operating from within a nearly 100-year-old military base near the village of Ashby de la Launde in Lincolnshire, a county in England’s east midlands. About a three-hour drive north of London, it is a scantly populated area encompassing flat fields that stretch across the landscape. The British government says publicly that the Digby facility conducts “research into new communications systems.” A more truthful account is that it is an important part of the sprawling covert surveillance network maintained by British and American spy agencies, GCHQ and the National Security Agency.

 (REF: theintercept.com/2017/09/13/digby-uk-nsa-gchq-surveillance/)