All these individual elements take their place in the overall history of the thermionic valve or vacuum tube.During its history the vacuum tube or thermionic valve has played a pivotal role in many historical events and its invention has changed the way of everyday life.
Shorn of the mains power supply components it even appeared in a battery portable set! It originally belonged to the Gaumont-British Film Co.
and later passed into the hands of the Rank Organisation.
A recent message in the forum requested information about reproducing the Bush logo. Despite the use of series-heater valves, the AC11 is an AC only set.
Peter Hughes kindly scanned a page from a book showing the dimensions etc., and emailed it to me. The heaters are connected in series and operated from a suitable tapping on the secondary of the mains transformer.
As the need to valves / tubes grew, so did the requirements for their performance.