Receptite Co.
1 The Mall Southgate London N14 (1928)

Brand: Stenode

Throughout its brief existence, Receptite Co. stood out by crafting bespoke receivers to customers' desires. [1]

Dr. James Robinson D.Sc., Ph.D., M.I.E.E., F. Inst.P., a design engineer at Receptite, etched his name into radio history. He's revered as the mastermind behind the revolutionary Stenode receiver and a pioneer in automatic tuning and direction-finding systems. His career later soared as Chief of Radio Research at the Air Ministry.

Taming the Overcrowded Airwaves: In the 1930s, Europe's airwaves thrummed with 204 stations, forcing a tough choice: clarity or selection. Dr. Robinson's ingenious Stenode defied the odds. It delivered both superior selectivity (quieting the static) and high-fidelity sound, allowing users to relish over 100 stations with exceptional crispness. [2]

A Forum discussion on Dr. Robinson's invention is here.

Two Models, One Vision: Dr. Robinson's vision materialized in two Stenode models: the core Stenode and the premium Stenode Radiostate, the latter equipped with a quartz crystal filter for pristine sound.
Aptly named for the Greek "narrow path," the Stenode navigated the congested spectrum with unmatched clarity.

Across the Atlantic: Interestingly, the Stenode Corporation of America, formerly known as the American Radiostat Corp., played a crucial role in bringing Dr. Robinson's vision to life by developing quartz crystals specifically designed for his revolutionary superheterodyne receivers. These innovative "tube-form" crystals fit seamlessly into standard sockets, making them readily accessible and paving the way for wider adoption of the Stenode technology. [3]

Patents: Robinson was granted at least four US patents for his work, ie US1821032, US1821033, US1898895, and US1908558. All four patents were filed between 1929 and 1930, and all four show some form of a center-tapped transformer crystal filter circuit.

Note: The unrelated "Receptite" brand of galena crystals by Cook & Co. in 1923/4 is mentioned for completeness.

[1] Wireless World Nov 28, 1928, Page Ad 30.
[2] Practical Radio Feb 1932, Pages 12 & 13.
[3] Radio Retailing (US) Jul 1931, Page 76.