The PY800 was one of the last rectifiers of its type to be developed and is based on the PY81 from 1952. It was specifically built as an efficiency diode for television line scan in sets using 110° deflection angle tubes.
The rectifier is specified as having a peak inverse voltage rating of 5,750 Volts, and a peak current rating of 450 mA. For sine wave use an input voltage of 1,500 Volts at 175 mA could be rectified. No voltage drop is quoted so the dissipation can not be given.
The anode has two flanges opposite sides of the central cathode. The anode plates are stitched together.
The anode seen from the side.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 72 mm tall.
References: Data-sheet & 1040. Type PY800 was first introduced in 1961. See also1961 adverts.