Charles Bovill (18 February 1911 - 9 May 2001)
was an electronics engineer and inventor who lived in England (UK).
During WWII, he worked for the Special Operations Executive (SOE), for which
he invented devices like Rebecca
and the S-Phone. During the 1970s and 80s,
he became known for his invention of the
non-linear junction detector (NLJD),
also known as the Broom.
was first sold by Allen International Ltd. in Westminster
(london, UK), which was a front operation of MI6. Allen International
was a subsidary of Technical Services Ltd., another MI6 front, operated
by his friend and colleague Lee Tracey, the inventor
of the Scanlock bug tracer.
Another invention of Bovill was the Photic Drive, a device that could
be used for crowd-control. It produced a combination of sub-sonic waves
and strobe light, and caused acute discomfort, disorientation
and sometimes epilepsy. In his laboratory at West Byfleet, he tried
it on his wife.
On 1 October 1973, he nearly lost his live when the IRA,
afraid that this device would be used against them,
wanted to place a bomb in his Westminster office. Fortunately,
the person placing the bomb was spotted on camera by Bovill's
colleagues, and eventually the bomb didn't go off.
The Photic Drive was later marketed in the US, where it was
successfully used against prison riots.
Charles Barton Bovill was born 18 Febrary 1911 at Battersea, south
London (UK). He was educated at Bedford School, the University
of Grenoble (France) and the Regent Street Polytechnic (London),
after which he joined HMV as a radio engineer in 1933.
In 1935 he made the move to the Air Ministry, where he worked in the
wireless telegraphy section, and three years later to Marconi.
During WWII, Marconi lent him to RAF Bomber and Costal Commands,
where he started working as a radio development engineer.
His work was noticed by the Special Operations Executive (SOE),
who recruted him in October 1941 for the Inter-Service Research Bureau
(ISRB); a cover name for the technical research and development
of the SOE. In April 1942 he became a flight lieutenant with the
Technical, Signals and Radar Branch of the Royal Airforce Volunteer
Reserve. In order to find corroded parts on airplanes, Bovill
developed the non-linear junction detector (NLJD).
Towards the end of the war, he briefly returned to the ISRB,
which lasted until May 1945 when he became a civilian again
and started working for Decca.
In 1972 he became technical director of Allen International Ltd.,
a company with a shop above a bedding shop in Westminster (London)
that specialized in miniature microphones,
bugs and other spy equipment.
According to friend and colleague
Lee Tracey, Allen International
was a cover for certain MI6 activities, just like his own company
Technical Security Ltd
For several years, Allen International supplied the Q-type
gadgets for the famous James Bond movies.
When the shop was closed down in the mid-1970s, the activities
were taken over by yet another MI6 front: Security Research Ltd.
in Guildford (UK).
In 1999, Bovill appeared in the fascinating Channel 4 documentary
The Walls Have Ears  in which he demonstrated the original
Broom in the shed behind his home.
is a device that is able to locate (radio) bugs,
even when they are switched off. It is based on his wartime
development of the non-linear junction detector.
During WWII it was used to find corroded airplane parts,
but Bovill discovered that it could also be used to find other
semiconductors, such as diodes, transistors and ICs.
The image above was taken from that Channel 4 documentary .
Just two years later, on 9 May 2001,
Charles Bovill passed away at the age of 90.
The following (co)inventions of Charles Bovill are featured on
In some literature, the Russians are credited for inventing the
Non-Linear Junction Detector (NLJD), as they came up with an equivalent
device around the same time as Charles Bovill did in 1972. However,
as Bovill already used the NLJD during WWII to find corroded parts on
airplaines, we assume that he is the original inventor.
It is quite possible though, that the Russians invented it completely
independently, or that they had information about Bovill's secret wartime work.
➤ More about the NLJD
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© Crypto Museum. Created: Thursday 17 September 2015. Last changed: Friday, 09 November 2018 - 10:17 CET.