Sir Ernest Harrison led Racal Electronics for nearly 35 years from 1966 to 2000. He joined the company, then a tiny engineering consultancy, in 1951. By the time he retired, nearly half a century later, Racal had spawned three large enterprises and one enormous one. There was a defence electronics company, a security concern, a telecoms network, and Vodafone, the world’s largest mobile phone company.

The success of Vodafone, which emerged from Racal in the late 1980s, gave Harrison credentials as one of the founders of mobile telephony in Britain and one of its most far-sighted postwar business figures.

Ernest Thomas Harrison was born in 1926 and went to Trinity Grammar School in Wood Green, North London. He qualified as a chartered accountant in 1950, completing his articles with Harker Holloway & Co. In 1951 he was the 13th man to join Racal, then based in Neasden, northwest London. As deputy managing director in 1961 he helped Racal to obtain a stock market listing and became chairman in 1966 when Ray Brown was lured away from the company he founded by the Ministry of Defence.

Before Vodafone was thought of, Racal became one of Britain’s foremost electrical engineers. In the late 1950s, at Harrison’s suggestion, the company invested heavily in a high frequency radio receiver that originated in South Africa. The cost almost smothered the company but when it was adopted by the British Army, Racal was on its way to becoming a stock market star of the 1960s. The company went on to sell its radios, and other civil and defence-related electronics, around the globe.

Racal grew rapidly through the 1960s and 1970s selling radar equipment and other components for electronic defence and communications systems. In 1969 Harrison led a merger between Racal and British Communications Corporation, in a move that bolstered Racal’s radio business. In the same year Racal took its first steps into the data communications industry by entering a partnership with Milgo Electronic Corporation of the US. In 1980 Racal bought Decca, beating off a rival bid from General Electric, the rival British company led by Arnold Weinstock. Racal wanted Decca, a name best known for the record label it no longer owned, for its expertise in radar and electronic defence systems.

Harrison, invariably known as Ernie, snapped up one of the two cellular radio licences awarded by the British Government in December 1982. One of the two licences had gone to a consortium led by British Telecom. Racal was thought unlikely to win control of the other because it faced stiff competition from two teams of bidders, one including Ferranti and the other Cable & Wireless. But Racal, with support from Millicom, a US electronics group, and Comvik, a Swedish company, won the day, thanks to what most observers saw as hopelessly optimistic growth projections.

Racal, under the direction of Harrison, said it expected between 250,000 and 300,000 people would be using “radiotelephones” by 1989 — three or four times the estimates of rival licence applicants. By the time 1989 arrived Vodafone had more than 500,000 customers on its own. It and Cellnet — the BT/Securicor-owned rival that won the other licence and subsequently changed its name to O2 — had persuaded 1.1 million Britons to own a mobile phone.

From an early stage Racal appreciated that its radiotelephones would transmit data as well as being used for speech communication. Indeed, Vodafone, as a name, came about when the first two letters of the word “voice’', and the first two letters of the word “data”, were crunched together and joined with the phonetic spelling of “phone”.

From a standing start, Vodafone grew to become one of the most valuable companies in Britain. Beginning as a subsidiary of Racal, it was hived off as a separate entity in 1988 and won full independence as a separate company with its own stock market listing in September 1991. At the height of the dot-com boom, Vodafone bought Mannesmann of Germany in one of the largest corporate mergers on record. In its wake, Vodafone was worth £230 billion, the highest value ever ascribed to a quoted British company.

That was two years after Harrison had handed the chairmanship of Vodafone to Lord MacLaurin of Knebworth, whose business reputation was made at Tesco, the supermarket. But between 1988 and 1998, when Harrison served as chairman of Vodafone, the value of shares in the company multiplied in value 12 times.

The rise of Vodafone halted when the dot-com bubble burst in 2001 and mobile telecom companies, including Vodafone, overpaid by the billion for so-called third-generation mobile licences. Its market value fell to barely one third of its peak. But in 2008, with 269 million subscribers in Britain, Continental Europe, the US and Asia and Africa, Vodafone was the largest mobile telecoms company in the world.

In the same month that Racal won the original licence, in 1982, a newspaper article described the new technology. “There is only one city in the world where the businessman, walking down Main Street, can take a 1.8lb portable radiotelephone from his briefcase, key in a telephone number and be connected in seconds to a colleague in say, London or New York. That city is Washington DC.”