Shortly after the end of the war during 1919, he left the Admiralty joining the Z Electric Lamp Co as their managing director. By mutual arrangement, valves were manufactured using Stanley’s patented technology and sold principally to the Admiralty and Post Office under the S.R. Mullard brand.
When the Z Electric Lamp company foundered in mid 1920, Stanley continued manufacturing there as the Mullard Radio Valve Co. Ltd. and as the business grew he moved in 1922 to a larger premises in Balham. At this time, production concentrated on specialized transmitting valves for the Admiralty and dull emitter R type receiving valves, however, with the commencement of public broadcasting by the fledgeling BBC, the demand for valves rose significantly and by 1924 our hard pressed Stanley needed to expand production which he financed by selling a 50% stake of the Mullard Radio Valve Co. Ltd. to N.V. Philips Gloeilampenfabriken of Eindhoven, Holland.
Original valve box images by kind courtesy of Alan Wyatt of The National Valve Museum = see more at www.r-type.org