Racal Ltd. was founded in 1950 by Ray Brown and George Calder Cunningham, former Plessey employees. The company name is derived from the first names of the founders: RAy - CALder.

With the commercial shortwave receiver RA-17, Racal introduced the circuitry of the „Wadley Loop“ - a particularly stable oscillator control circuit (after its inventor and then co-worker, Dr. Trevor Lloyd Wadley, 1920 - 21.05.1981) - into professional receiver construction.

Racal Engineering Ltd. became Racal Communications Ltd. in 1979, in 1990 it was merged with the military communications technology branch to become Racal Radio Ltd. and in 2000 it was taken over by Thomson-CSF Racal.

The US branch Racal Communications Inc. was based in Silver Spring 1965 - 1971 and in Rockville 1972 - 1997.