Maker's Name: 
c. 1970
3.5 × 3.5 × 11.8 cm

Glass envelope, magnoval base, top cap. This valve was used in early colour TV sets for horizontal deflection of the electron stream in a colour cathode ray tube. The extensive brown staining inside the envelope is barium from the cathode. This indicates that the valve was driven hard for a long time. Flecks inside the envelope suggest that the envelope has been bombarded and the oxide coating partly stripped.