
General Electric CA101 Pilotron triode (McVitie Weston valve collection), 1918
1918
1918
1924
1893
1954
1930
1927
circa 1950
circa 1920
1960-1970
1954
1924
1967-1971
1930
1920
1949-1950
1923
1955
1960
1933
1925
circa 1945
1954
1940
1930
1935
1910
1940
1910
1914-1934
circa 1947
circa 1930
1920
circa 1920
1949
1910
circa 1903
circa 1920
circa 1920
1922