
Mullard EF9 VM RF pentode valve (McVitie Weston valve collection), 1939
1939
1939
1936
1946-1948
1936-1955
1935
1934
1946
1956
1951-1953
1929-1935
1931
1950-1951
1953
1940-1944
1943
1937-1937
1942
1930-1955
1939-1955
1940-1949
1937-1938
1937-1938
1946
1948
1928
1932-1942
1938
1924
1955
1936
1935
1946
1940
1940
1955
1950
1935
1940-1950
1930-1950
1950
1956
1938
1947
1938
1948
1938
1935
1938
1940
1928