J & A Margolin Ltd. started trading in 1934 in Old St. London, selling Accordions and Banjos. They soon started making record players though and this, along with the later introduction of radios to the catalogue, went on to become their main business. By WWII they had ceased making musical instruments but continued after the war until far eastern competition forced them to close in 1969.

 The range of Banjoleles and Banjos they sold were branded as Broadcaster were marked: "Made by J. & A. M. of London.", (the accordions were branded Pietro). Despite the originally quite premium looks with everything being covered with nacrolaque, (aka pearloid, aka mother of toilet seat), they were not great instruments and the metal work was very thin lacquered brass. In later models they toned down the use of nacrolaque and brass until in the end they just looked like standard low end Banjos. 

Gretsch also made a range of Banjos they called Broadkaster - spelt with a K and these were 5 string only