The story of Broadcast Technology- in Pictures from our Sales Archive

Radio waves were discovered in the 19th century, and were first put to practical use by Italian inventor Guglielmo Marconi. At first a wavelength of a specific frequency was generated, often with a spark coil like this.

A signal could then be sent using Morse code, then in common use on the telegraph system. Instead of using telegraph wires, radio waves were used instead. This allowed communication

During the first World War, wireless was used by all the services for communication. This beautifully original 'Mk333Tuner' was dveloped for th Army, still for Morse signals. Towards the end of the war, the use of radio valves brought in the possibility of transmitting a voice by wireless. After the war, experiments were carried out at the Marconi factory in Chelmsford which involved transmitting 

More people became interested in wireless as a hobby, tuning in on home built sets to listen to the radio signals from ships (like people still do with aircraft), and the experiments from Chelmsford. A group of manufacturers who saw that what was seen as a disadvantage of wireless, that anyone could 'listen in', could be used to advantage- by 'Broadcasting' from a single transmitter to any number 

The radio manufacturers persuaded the Government to allow public broadcasting, to be paid for by a Receiving Licence (although at first, the BBC was a private company, paid for by the shareholders.)
The simplest radio receiver is a 'Crystal Set'- a natural crystal is used to detect the signal, which causes a coil to resonate, producing a signal that can be heard on headphones. But if valves are us

This 3 valve receiver made by Sterling is an example of one of the earliest and most collectable wireless sets of the 1920s. The valves are exposed, the panel is engraved with the maker's name and the 'BBC' Stamp'- required from 1922-24 on any British made wireless equipment. It had to bear the words 'Type Approved by Postmaster General'. (Later changed to 'Entirely British Manufacture').

A commercially made wireless set was an expensive item. This Gecophone 2-valve set (often called the 'Smoker's Cabinet') cost £25 (plus batteries and headphones) in 1923. The amplifier unit below, to operate a loud-speaker, cost £13.10s extra. A working man might have earned £2 a week. These sets were therefore quite rare, were quickly outdated and thrown away- so a good original example like this