5 Nov. 2015 – Visit to Henlow Museum

Dave
Dave

Twenty members gathered at the Henlow Signals Museum to hear Deputy Curator, Dave Thompson talk about early communications up to and including WWl.

Dave started with some predictions made in 1900 while radio was still in it’s fledgling state. A certain John Watkins writing of What May Happen in the Next Hundred Years, in December 1900 Ladies Home Journal, predicted that by the end of the century “a husband in the middle of the Atlantic will be able to converse with his wife sitting in her boudoir in Chicago” A commentator in the London Spectator, quoted in the Nov. 1902 edition of the Los Angeles Times, “Some day men and women will carry wireless telephones as today we carry a card case or camera” If only he had realised he was predicting the mobile phone complete with camera and games and much more, all built in! Progress was made by the Marconi company in mobile communications as reported by Western Electrician in 1901.

Dave went on to describe early sets, most were very large and heavy, and in 1901 Marconi described a mobile set up built on a heavy steam motorcar (a bus) that provided communications up to about thirty miles. Of course this was all spark transmissions in Morse.

Wartime proved to be the driving force behind smaller and more efficient sets. Dave not only described some early sets, but went on to show the actual sets from the museum collection. (see photos below) Of course, telegraphy was also taken up by the Navy and the Royal Flying Corps from about 1915, which proved invaluable in the First World War. The equipment used in aircraft didn’t have a receive capability due to the interference from the engine and wind noise. The aircraft had to rely on a large letter K laid out on the ground by the runway to acknowledge that their transmissions were being heard!

Much development was carried out by the Marconi Company and the War Department resulting in smaller sets with the move from Long Wave to shorter waves and eventually VHF.

TX T21C used by the RAF in the 1920s
TX T21C used by the RAF in the 1920s
The Rx TF used by the RAF in the 1920s
The Rx TF used by the RAF in the 1920s