1896

Business established in Clerkenwell, London, by Mr A C Cossor, specialising in blowing scientific glassware.

1902

Cossor makes first British example of the Braun-type cathode ray tube. Around this time Cossor also produces earliest X-Ray tubes for Crookes and Lodge, first valves for Fleming and experimental apparatus for Marconi. Cossor makes many innovations in the field of vacuum-tube and thermionic technology, including the twin-beam cathode ray tube.

1914

Military requirements of the time encourage Cossor to diversify its interests.
Post-war the company moves into the fields of radio and television.

1927

Cossor becomes famous for its 'Melody Maker' radio receiver.

1935

A Cossor cathode-tube is used in the Weedon Experiment - demonstrating echoes of a target aircraft using the BBC's Daventry transmitter.

1936

Becomes the first company to sell a television receiver in the United Kingdom .

1937

Cossor builds the receivers for the 'Chain Home' primary radar system- the world's first to go into production and operational service.

1939

Cossor involved in a range of major projects including airborne radar.

1945

Cossor moves into secondary radar for air traffic control, a technology that it went on to develop as a major company strength.

1958

The company moves from its cramped and ageing facilities in Highbury, North London , to Harlow in Essex.

1961

Cossor is acquired by Raytheon, which itself is already a major player in radar technologies. Under its Raytheon parentage Harlow continues pioneering major advances in this field including Monopulse Secondary Surveillance Radar (MSSR), Identification Friend or Foe (IFF) and SSR Mode S.

1981

Cossor Falconer Precision Approach Radar.

1982

First Monopulse Secondary Radar is sold.

1991

Company acquires STC's GPS business. This results in the subsequent development of the GAS-1 anti-jam antenna technology.

1997

Raytheon Systems Limited is formed.

2005

RSL's unique ADS-B solution publicly launched and field trials and demonstrations commence.