Cossor 52-KU Full wave rectifier (5Z4G CV593 CV1863 GZ32)
The original 52KU was the Cossor code for the GZ32 full-wave rectifier. This rectifier is a medium power device for general purpose use. It probably would have been used in audio power amplifiers or modest radio transmitters or industrial equipment. The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 80 mm tall. The 52KU was first introduced in 1949.