Geoffrey Blundell

20th September 1923 to 15th January 2003

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Explorations in radar and messages from the brain

Michael Strutt
Tuesday February 11, 2003
The Guardian

The electronics engineer Geoffrey Blundell, who has died aged 79, developed radio microphones that are used worldwide in filmmaking and broadcasting, worked with John Logie Baird and met the Maharishi Mahesh Yogi. During the second world war, he worked on the key RAF radar component, the cavity magnetron, and later developed the mind mirror to measure brain patterns among healers, meditators and gurus.

Blundell's first microphones - allowing performers to move without cables or booms - used radio valves, since transistors did not become available until the mid-1960s. By 1997, amidst the rising waters of the film Titanic, they withstood studio action for six months.

Blundell was born in Studley, Warwickshire, one of four children of a production engineer. He was educated at his local grammar school and at Ratcliffe College, near Leicester, where he made crystal sets for other boys to ensure their secrecy about his own use of the primitive radios. At the age of 17, he joined EMI, where, as a design engineer, he worked with Logie Baird.

Then came his war work on the magnetron, which was used on Bomber Command's target location system, H2S radar. In the 1950s, he made amplifiers and tuners for the hi-fi industry. In 1963, he started Audio Ltd, breaking through in 1968 when Audio microphones were used on Stanley Kubrick's film, 2001: A Space Odyssey.

During the pre-Thatcher years, only two or three people at Audio were electronic experts. When hiring staff, Blundell often chose someone who played an instrument or wrote poetry. But he was good at spotting potential, trained people well and did not neglect the cash flows.

Then, in the early 1970s, came a collaboration that changed his life. He accepted a friend's invitation to join a course in biofeedback, the electronic monitoring of physiological responses, being run by Maxwell Cade, a former government physicist, and his wife Isabel. Intrigued, Blundell suggested he could design improved monitoring devices, and produced a meter that enabled students to monitor improvements in the flexibility of their autonomic nervous system. He then designed a replacement for the one-channel EEG (electroencephalograph), and other devices.

In part, the courses were a test laboratory for Cade's research with Dr Ann Woolley-Hart, of St Bartholomew's hospital, into altered states, including deep relaxation, aimed at helping cancer patients. But to carry the work further - and study the relationship between the alpha, beta, delta and theta rhythms of each brain hemisphere - they needed a portable brainwave analyser, an EEG machine that could display the rhythms simultaneously.

Blundell produced his first mind mirror EEG machine in the mid-1970s. It showed that, as suspected, students achieving states of deep relaxation were producing particular combinations of brainwave patterns as both brain hemispheres synchronised. One of these combinations had pronounced alpha rhythms, and Cade, who had studied eastern philosophies, called it state 5, claiming it was the pattern of the awakened mind.

Blundell and Cade began regular research with prominent British healers and, using two mind mirrors, found that when the healer directed healing energy through their hands to a client, the healer produced a state 5 pattern, and induced a similar one in the client. It was a spiritual search which led Blundell to an audience with the Beatles' guru, the Maharishi - though, bemused by the experience, all he could recall was '"the pink froth emanating from his lips".

In 1975, Blundell joined Britain's Tibetan Buddhist DzogChen community, and became a pivotal member. In 1988, with his second wife, Helen Stapleton, he travelled with the group in a 90-strong caravan to western Tibet.

Blundell's approachable manner and thirst for knowledge made him many friends among people in the experimental arts. Illness from 2000 forced him into near retirement, but he was given devoted care by his friends, and by Helen, from whom he had separated. He diligently helped to resolve the pre-production problems of the last microphone he designed. His wife survives him.

• Geoffrey Gordon Blundell, electronics engineer, born September 20 1923; died January 15 2003.