Experimental transmitting ‘jigger’ used by the Marconi Company, 1899
1899
1899
1900-1950
1899
1898
1900-1950
1892
1923
1915
1954-1983
1930-1950
1924
circa 1925
1910-1930
1924
1948
1904
1940-1945
1890-1910
1950s
1940-1969
1950
1903
circa 1991
unknown
1920-1930
1950-1969
1923
1920-1950
1930-1950