Economic Electric Co.
64 London Road, Twickenham (1911) 

Economic Electric Ltd.
64 London Road, Twickenham {1914 – 1931)
303 Euston Square, London, NW5 (1925)
10, Fitzroy Square, London, W1 (1914 - 1931)

Tube Brands: Dextraudion,  Xtraudion.

Economic Electric, Ltd. was a pioneering British electrical company based in Twickenham, active from the late 19th century to the early 1930s. It was known for its innovative vacuum tube designs, like the Xtraudion and Dextraudion valves, which advanced early radio technology. Despite technical successes and expanded operations in London, the company ultimately succumbed to financial difficulties and market shifts caused by the rise of pre-assembled radios, leading to its liquidation in 1931.

Overview and Founding
Economic Electric, Ltd, based in Twickenham, was a notable British electrical company active from the late 19th century into the early 20th century. Established officially as a private company in 1914, it took over the business of S. G. Frost and D. Poupart, electricians who had been trading under the Economic Electric Co. name since at least 1896 [1][5]. The company was headquartered at 64 London Road, Twickenham, and was involved in manufacturing, merchandising, and warehousing electrical goods.

Products and Innovations
Economic Electric, Ltd became notable in the early 1920s for its work in vacuum tube (valve) technology, a critical component in the development of radio and electronic equipment of the era.

Xtraudion Valve
In 1922, Economic Electric, Ltd introduced the Xtraudion valve, a thermionic triode with several distinctive features [6]:

• The anode was formed as an inverted channel or trough, differing from the standard cylindrical design.
• The grid was robust and completely surrounded the straight filament wire.
• The filament required 4 volts and consumed 0.4 ampere at maximum, with an anode voltage of 50 volts.
• The valve was considered a "hard" valve, signifying a high-quality vacuum.
• For rectifier use, a 5 megohm grid leak was recommended.
• The Xtraudion was marketed as suitable for rectification, oscillation, and amplification, and was advertised as infringing no patents.

Dextraudion Valve
A variant called the Dextraudion was also produced:

• This was a "dull emitter" valve, meaning it operated at a lower filament temperature and thus had reduced power consumption.
• The Dextraudion required only 0.1 ampere at 1 volt, with an anode voltage range of 20 to 60 volts.
• It featured a tough, special-character filament capable of operating at extremely low currents (as low as 0.025 ampere at .3 to .5 volts), making it approach the characteristics of a "cold emitter."
• At these low currents, the filament glowed only a dull red and was nearly invisible.
• The high saturation point allowed it to effectively drive a loudspeaker with a grid bias of 2 or 3 volts.

Business and Market Presence
Economic Electric, Ltd positioned itself as a wholesaler and retailer, serving both the trade and the public. By 1922, the company had expanded its operations to include showrooms at 10 Fitzroy Square, London, and advertised widely in technical and amateur radio publications. Their triode valves were marketed as the "latest and best development" in three-electrode valve technology, emphasising unique construction and high amplification characteristics.

Liquidation and Legacy

• Financial Collapse (1931): Liabilities of £10,153 dwarfed £1,016 assets, driven by unsold inventory and radio’s market disruption [2].
• Post-Liquidation: No successor entity emerged, though its valve designs influenced later British radio components.

Distinct from Liverpool Entity

The unrelated Economic Electric Co., Ltd (Liverpool) (1911–1911) focused on appliances and liquidated within months under S. Brownlee [3][4][5].

Technical Impact: Economic Electric’s Xtraudion and Dextraudion exemplified early British innovation in thermionic valve technology, bridging the gap between experimental electronics and commercial radio

[1] The Electrical Review Jul 24, 1914, Page 143.
[2] The Electrical Review Oct 30, 1931, Page 675.
[3] The Electrical Review Mar 31, 1911, Page 523.
[4] The Electrical Review Nov 3, 1911, Page 738.
[5] The Electrical Review Nov 10, 1911, Page 778.
[6] Harmsworth Wireless Encyclopedia, 1922, Page 2249.