
Mazda QP.240 battery double output pentode valve (McVitie Weston valve collection), 1935
1935
1935
1910-1960
1906-1972
circa 1930; 1920
1981
circa 1925
1990-1995
1996
1985-1995
1996
1986-1996
1922
1947
2020
1990-1995
1986-1996
1922
1986-1996
1986-1996
1986-1996
1986-1996
1922
1977
1986-1996
1980
1923
1932
circa 1925; circa 1925
1901
1992-1996
1912
1923-07
1940-1960
1928
1948-1958
1951
1950
1840
1957
1957
1951
1953
1939-03-28
1961-11-21
1939-07-24
1958 May
1937