The CV4042 (commercially the S19G6F) is a special quality indirectly heated half wave rectifier with flying leads intended for high voltage power supplies. The design is optimised for long life under rugged service conditions.
The KB/FE identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the FE identifies the maker as STC, Oldway (Additional to Paignton factory 'F').
Vibration resistance is achieved by the use of double mica discs top and bottom. There are additional vertical support rods. Note also the use of ceramic insulators for the anode.
The commercial Type S19G6F is also present indicating complete equivalence.
The thin glass tube envelope is 18 mm in diameter and, excluding the base wires, is 42 mm tall.
Reference: Data-sheet. Type CV4042 was first introduced in 1958. See also1958 adverts.
