Extremely rare octal-based metalised glass tubes designed for the HF stages of television receivers. Originally designed and manufactured by Mazda Ediswan in England in 1938, these high frequency glass pentode tubes were manufactured until 1948. With a variable-mu characteristic, and large signal handling capacity, these tubes are printed War Office arrow CV21, they have gray metalised glass finish, are wrapped in a corrugated cardboard and tissue paper roll, and boxed in brown miltary boxes printed CV21 10E/21.
Data sheet
Extremely rare octal-based metalised glass tubes designed for the HF stages of television receivers. Originally designed and manufactured by Mazda Ediswan in England in 1938, these high frequency glass pentode tubes were manufactured until 1948. With a variable-mu characteristic, and large signal handling capacity, these tubes are printed War Office arrow CV21, they have gray metalised glass finish, are wrapped in a corrugated cardboard and tissue paper roll, and boxed in brown miltary boxes printed CV21 10E/21.