Mullard EF9 VM RF pentode valve (McVitie Weston valve collection), 1939
1939
1939
2000-100 BCE
1938 and 1951
1955; 1830
1939
1939
1990-96
circa 1939
1801-1892 (prepared); 1946 (element replaced)
4000-2001 BCE
1839 (original); circa 1988 (replica)
1939
1903 (original); 1982 (model)
1830 (original); 1967 (model)
1939
1939-04-13
1939-08-25
1956-09
1939-08-25
18 Janury 1948
1939-05-24
1939-01-30
28 October 1939
1939
1939
1939
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1939-07-07
1953-4
1939
1939
1970-1900
1970-1875
30 CE
30 CE
2686-2613 BCE
1939
1859; 1986
1945-50
1939
1939