Two copper oxide high voltage rectifiers: 1934 British H 176 (2 units); 1935 British J 176 Two copper oxide high voltage rectifiers 1934-1935
Nine copper oxide low power rectifiers: 1931 British full wave 250 u.a.; 1931 British half wave WX6; 1934 British full wave 10 m.a.; 1934 British full wave 250 u.a.; 1942 British half wave WX6; 1942 British half wave WX6 miniaturised; 1942 Swedish full wave 10 m.a.; 1942 German half wave; 1946 British half wave KG3 Nine copper oxide low power rectifiers 1931-1946
Eight copper oxide rectifiers: 1928 British R4-55; 1928 American A-10; 1930 British H.T.4; 1930 British H.T.3; 1931 British H.T.10; 1931 British A.6; 1932 British A.6; 1934 British sample plate Eight copper oxide rectifiers 1928-1934