Clive trained as an electrical engineer at Rugby, and when working for EMI  was head-hunted at the in 19389, at  start of the war,  to work as a civilian attached to War Admiralty. Eastney Portsmouth  as part of  Watson Watts team  developing RADAR.

 He transferred to ASRE, Admiralty Scientific Research Establishment, Witley in Surrey in 1942, at the same time the noted astronomer, Fred Hoyle, with whom he retained communication for many years. 

At Witley there was research being undertaken on radio counter measures against "LOP-gap". There designs were being developed for control systems and projectiles which would increase its susceptibility to radio jamming.

He passed examinations to be Associate Member of  Institute of Electrical and Electronics Engineers in April, 1950 and  in that year he moved to the Signal Scientific Research Establishment, (Black Down) Haslemere.

In 1952 he transferred to Portsdown in Hampshire , Admiralty Research Establishment (ARE) Admiralty Surface Weapons Establishment (ASWE)

Defence Evaluation and Research Agency (DERA)at the Admiralty Research Establishment.

During this time he set about developing his most significant invention  - RACON - This became a Trinity House project and is now in Science Museum.

His last invention , in the late 1970's was a personal alarm system using phone line which shortly before his death he took, without benefit of a patent , to show his old colleagues at Decca. The idea was dismissed out of hand but shortly after he died a personal alarm system was produced based on the principals he had described.

As children his life was mysterious to us. My sister and I suspect he was seconded to Military Intelligence but we simply do not know.
  There were his' lecture' tours of universities in the US  in 1948 ( when he couldn't tell us what he was doing but could present open lectures to students) and things like visits into Germany at the height of the Cold War .

On one occasion he arriving home in a naval helicopter that landed on the nearby golf course and on another time he was mysteriously whisked off in chauffeur driven limos- to Whitehall for de briefing.  He carried the rank of Commander when on naval bases or on board ship and Wing Commander in RAF. he told me that during the war he carried a Pink security card which, he said, had the same clearance as Churchill, how true that is I have no idea.

His final move was to GCHQ, Benhall Cheltenham  in 1958 where he took up a research post  at GCHQ  the British intelligence agency that has two missions: signals intelligence (Sigint) at Benhall and Information Assurance at Oakley.   Before he retired he was offered post of Chief Scientist but declined. 

He was awarded an OBE for his services to science in 1966 and received it, oddly enough, on the same day Peter Sellars one of our most brilliant comedians, got his CBE.

Ultimately his working life remains  pretty much a mystery to his family, although in 2010 things began to emerge for the locked  box of the 30 year secrecy rule.

 Confirmation of his  Admiralty role here...Civil Officers serving under the Admiralty 1939-1945

  Research Article  Journal of Navigation (1954), 7: 181-186  Copyright © The Royal Institute of Navigation 1954

 A Racon Beacon for Reception by Civil Marine Radars - author - C. Randall-Cook  (Admiralty Signal and Radar Establishment )

 In about 1946 work was begun both in the United States and in the United Kingdom on the development of radar beacons which could be used to make certain required points more conspicuous and to increase their detection range. 

Two basic types of beacon were considered: ramarks, which are intended to give bearing information only and which appear on the PPI as a bright radial line passing through the position of the ramark, and racons, which give range as well as bearing information. The range information is given by die beacon transmitting one or more short pulses, the first of which appears on the PPI at the correct range and bearing of the beacon.

 Admiralty Signal Establishment Extension, Witley: report on possible radio countermeasures against "LOP-gap", an illustration showing how various details in design of control system and projectile would increase its susceptibility to radio jamming

Covering dates    1947

Availability         Open Document, Open Description, Normal Closure before FOI Act: 30 years

Former reference (Department)      ACSIL No.ADM/47/359

Held by            The National Archives, Kew

Scope and content          

Admiralty Signal Establishment, Haslemere: report on HMS VANGUARD ( seen here ) trials and observations of radar and W/T equipment by members of ASWE staff

Covering dates    1947

Availability         Open Document, Open Description, Normal Closure before FOI Act: 30 years

Former reference (Department)      ACSIL No.ADM/47/410

Held by     The National Archives, Kew

an article on the History of Radar HERE

 Sept 1939 Register  

9 The Warren , Carshalton U.D., Surrey, England

Percy David Randall Cook B  3 Mar 1883 Financial & Property Broker Married

Kate Cook wife   13 Feb 1882  Unpaid Domestic Duties

Joan H R Mewes Dau   30 Aug 1911  "     "         "married to Bernard Mews photographer

Clive Randall-Cook 11 Apr 1908 Electrical Engineer Graduate -  married 30 Sept 1939