Radios
The very first application of the thermionic valve dates back to 1904 when J.A.Fleming used the diode for the detection of high frequency radio signals. Before that, radio receivers were based on the galena crystal, which has a rectifying property. With the invention of triode, which could not only rectify but also amplify, long-range wireless communication became possible.
Televisions
The invention of the cathode ray tube (CRT) together with the amplification valves brought us the first television. Televisions then became an un-replaceable part of our daily life. Although traditional CRT TVs are being replaced by flat LCD panels nowadays, but please do remember the first TV was made of tubes.
Early Computers
The first generation computers were entirely built based on valves. They were huge in size and consumed massive amount of power. Moreover they were unacceptably unreliable – bad valves had to be replaced regularly to keep the computer operating. However, thermionic valves did open the first page of the modern computers in the human history.
