'Radiojoy' branded equipment was manufactured by F. W. Mountjoy & Sons Ltd, the distributor is unknown.

The founder of the Radiojoy brand, F. W. Mountjoy, began manufacturing radios under his Radiojoy brand in his garage at 71 Quadrant Road, Onehunga in Auckland.  Vaughan B Mountjoy and Graham Mountjoy were his sons.  Vaughan joined the family business in 1937 as a radio serviceman. Both brothers were in the RNZAF and served in the Pacific theatre, Vaughan as a Radio Mechanic (servicing radar in the Catalina bombers) and Graham as an Aircraft Mechanic. Graham is believed to have come into the company after WW2. Graham and Vaughan took over the company during the 1960's.