 Radiotelegrams were received and forwarded to London for the price of 11d per word; the service proved successful and in 1924 a second mast with callsign 'GKU' was added.By 1926, as experiments with short-wave communications proved successful, Devizes expanded again with the installation of Britain's first short-wave maritime transmitter.Again the service proved successful and the GPO investigated the possibility of expanding the Devizes site again; however, the limited space on the site led the company to open a new station at Portishead, Somerset, and close the Devizes station in 1929.