David, G8UOD began by saying his talk would cover the period between WWl and WWll, but it was pointed out that, although the country was not involved in a World War before 1939 there were numerous smaller conflicts involving Great Britain. During this time progress was being made in communications, and by 1933 the first of the ‘numbered’ sets was in use. Of course, it was called Wireless Set Number One.
At the start of WWll numerous sets from the first war were still being used, most likely due to the effects of the depression. However with the onset of WWll the Royal Signals quickly organised their ever growing numbers into various groups of command. In 1939 they totalled 43,332 persons which grew to 150,990 by 1945. All aspects of communications were eventually covered from laying land lines to mobile communications, cryptographic, and even deception transmissions as cover for the D Day landings.
Photos from Wireless for the Warrior http://www.wftw.nl/wsets.html