The CV5259 (commercially the U329) is a television efficiency diode.
Considerable energy is fed to the line deflection coils and this has to dissipate during flyback. The efficiency diode channels this energy back to the supply rail smoothing capacitors for use on the next line scan.
The rectifier is specified as having a peak inverse voltage rating of 7,500 Volts, and a peak current rating of 450 mA. No voltage drop is quoted so the dissipation can not be given.
The Z identifies the maker as MO Valve Company, Hammersmith.
The anode connects to the base pins.
The Commercial Type U329 is also on the envelope indicating direct equivalence.
The connection from the cathode to the top cap is insulated with a ceramic bead.
The thin glass tube envelope is 21 mm in diameter and excluding the B9A base pins the length is 69 mm.
