Halcyon Wireless Supply Co. Ltd.
110 Knightsbridge, London SW1 (1926)
313-319, Regent Street, London, W1 (1928)

Halcyon Wireless Co. Ltd.
27a Pembridge Villas, Notting Hill Gate, London W11 (1930)

Halcyon Radio Ltd.
Valetta Road, Acton, W3 (1934)
Sterling Works, Dagenham, Essex (1937)

The company manufactured portable battery radio receivers from 1923 and added mains-powered Radios & Radiograms to their production in the early 1930s. They became part of Ismay Industries in 1935 and the Halycon brand continued until the late 1930s.

Halcyon Wireless Supply Co. Ltd. was registered as a private company in October 1923 with First Directors A. S. Marks & R. A. Emby, [1]

By 1927 they were manufacturing a range of portable radios and a discretion of their products was given in the February 1927 issue of the Electrical Review.

The company specialises entirely in portable receivers, and three, four, and five-valve receivers are exhibited in both Oak & Mahogany cabinets. The five-valve receivers are guaranteed to give loudspeaker reception anywhere in England without external connections. Although a straight circuit, the makers are prepared to be guaranteed loudspeaker reception in London of the London, Daventry, Paris, and Berlin stations. In addition, the Company is showing for the first time a seven-valve portable superheterodyne set in exceedingly compact form, and all valves and batteries, as well as an Amplion speaker, are enclosed in the cabinet. [2]

In June 1929 they acquired a large modern factory in Slough due to the demand for their portable radios. [3]

In 1934 the introduced universal (AC or DC Mains) powered radio with a large range of features as described below;

• AC or DC Mains without Alteration.
• For the first time, listeners on DC circuits may purchase an up-to-date receiver without troubling about the change-over. Halcyon Universal is equally efficient on both main supplies.
• Exclusive Automatic Volume Control
• This gives real A.V.C. Weak signals are built up to loudspeaker strength. Over powerful signals are damped down to listening strength. A predetermined volume is thus automatically maintained for the first time over all stations.
• Anti-Interference Circuit Built-Into Set.
• This obviates mains interference perfectly and gives a silent background. The fact that the circuit is designed to suit the set ensures satisfactory performance.
• Use of metal rectifiers for mains rectification and Westectors for AVC and detection.

These features are used in the Model 4501. [4]

In 1935 Halcyon Radio Ltd., of Sterling Works, Dagenham was part of Ismay Industries [5]

The Halcyon brand continued under Isamy until the late 1930s.[6]

[1] Electrical Review Nov 2, 1923, Page 668.
[2] Electrical Review Feb 25, 1927, Page 821.
[3] Wireless World Jun 5, 1929, Page 599.
[4] Wireless World Aug 17, 1934, Page Ad 30.
[5] Broadcaster & Wireless retailer Apr 20, 1935, Page 17.
[6] Wireless World May 28, 1937, Page Ad 7.