Charles Samuel Franklin (1879–1964), who published as C. S. Franklin, was a noted British radio pioneer.
Franklin was born in London, the youngest of a family of 13, and educated at Finsbury Technical College in Finsbury, England, under Silvanus P. Thompson. After graduation in 1899 he joined the Marconi Company where he spent his entire professional career. He was first sent to South Africa to provide equipment for the Boer War, then spent 2 years in Russia. After his return to the UK, he invented a number of important radio devices including the variable capacitor (patented 1902), ganged tuning (1907), variable coupling (1907), coaxial cable, and the Franklin oscillator.
Today Franklin is best known for the Franklin beam aerial, his shortwave antenna. From the Marconi company's Poldhu station in 1923 and 1924, he sent shortwave transmissions to Guglielmo Marconi on his yacht Electra in the South Atlantic.
Franklin was also active in early television development. In 1935 the trustees leased part of Alexandra Palace to the BBC, which used it as the production and transmission center for their new BBC Television Service. Franklin designed its antenna, and the world's first public broadcasts of high-definition television were made from this site in 1936.
Franklin received the 1922 IRE Morris N. Liebmann Memorial Award "for his investigations of short wave directional transmission and reception".