The school was established at Leydene House, East Meon, near Petersfield, Hampshire, England and was commissioned as HMS Mercury on 16 August 1941 under the command of Captain Gerald Warner.

The base went on to house both the Communications and Navigations faculties of the Royal Navy's School of Maritime Operations (SMOPS).

It had moved to Eastney to study Radar direction finding, with appointments being made there from 30 December 1935, but the apparatus not arriving until 14 July 1936.

The Production department had been set up in Whitwell Hatch Hotel at Haste Hill, Haslemere by the end of May that year, with a small part of the establishment remaining at the old Signal School in Portsmouth.

Later developments saw the establishment of laboratories and workshops at King Edward's School, Witley, valve production going to Waterlooville and aerial manufacture to Nutbourne.