Antique Radio Display
On the 18th Of May 2006, Jack bought part of his collection of Vintage Radios and Gramophone equipment to the club and displayed them for the members. What followed was a fascinating evening, that demonstrated the diversity of materials and technology that has been seen over the past eighty years.
Photographs of the display are shown below -
The Life Story of the Radio Valve.
By: Robin Page-Jones G3JWI
The radio valve was patented in 1908, but was not widely used in wireless equipment until the first world war. It was the coming of broadcasting in the early 1920's which triggered the mass production of valves. Since then, many types of valve have been produced.
The second world war saw great improvements in valve design as well as the invention of completely new types. Perhaps the most noteworthy was the cavity magnetron which revolutionised RADAR, and gave Britain the edge in air defence.
Valve production reached a peak just after WW 2. In the late forties
computers used up to 10,000 valves, mounted in racks, filling a whole room. Double triodes [6] were widely used in these early computers.
But the writing was on the wall when first primitive transistor was
invented in 1947. The transistor [7] came into general use in radios the 1960's and "trannies" became the trendy thing for young people to carry about. As time went by the transistor completely ousted the valve except for special purposes.
In its turn the individual transistor gave way to the integrated circuit or "chip" This technique enabled a large number (sometimes millions) of transistors to be etched on to a small piece of silicon. [8], [9] and [10]
However, valves have not completely disappeared from the domestic scene.
The cavity magnetron, which did such sterling service in WW 2, is alive
and well and working peacefully in almost every kitchen - generating radio frequency power for microwave oven.