Alec Harley ReevesBefore the war Alec Harley Reeves worked at ITT in Paris where he invented and patented Pulse Code Modulation (PCM).  This is a method of communicating analogue waveforms as digital pulses which enable robust communications in spite of interference with signals that can be reconstituted at repeater stations between communications links.  At that time, the electronics technology of valves meant the technique was not commercially viable.  However, from the 1950s onwards with the arrival of transistors and solid state electronics, PCM started to gain more widespread use.  Today it is the backbone which underpins the worldwide digital communications revolution. 

During the war Reeves worked in Purbeck and invented Oboe - a radio precision bombing aid.  It was used to great effect by Air Vice Marshall Bennet's Pathfinder Force.  Flown mainly in the fast, high-flying Mosquito aircraft, a signal from ground control gave the precise moment to release target indicator bombs, so marking the dropping zone for the main force of following heavy bombers.  Hitler was greatly perturbed by the RAF's abiulity to score direct hits on the Krups armament works at Essen through 10/10th cloud.

In the 1960s Reeves went on to pioneer the development of fibre optic links at Standard Telephone & Cables. 

Reeves' revolutionary development of Pulse Code Modulation and groundbreaking work on fibre optics has prompted a few to title him the 'father of the information age'.  However, he has never gained the widespread recognition he probably deserves - perhaps because his outstanding contributions were more in the realm of ideas rather than in more tangible equipment or demonstrations.

Alec Harley Reeves CBE
10 March 1902 - 13 October 1971

Papers & Links etc.
Web pagewww.alecharleyreeves.com 
Wikipedia page:  biography Alec Harley Reeves  accessed Feb 2011
or try:  http://en.wikipedia.org/  with search words: Alec Reeves 
Group in March 1942:  Group 4  OBOE - Precision Bombing

copyright Purbeck Radar Museum Trust 2013  |  www.purbeckradar.org.uk  |  version 8f - 9 May 2015

Page last updated: 25 May 2011