The CV493 is the commercial 6X4 HT rectifier. A common cathode is employed passing through two anodes arranged at right angles to one another.
At 325-0-325 input to the rectifier this will give an HT rail higher than is required for most domestic equipment. Use for audio amplifiers and small transmitters is most probable, or driven at 250 Volts for radio receivers.
See alsoEZ90 from Brimar and the 12X4 12 Volt heater version.
Looking between the anodes the cathode tube coating can be seen. The single insulated heater wire passed through the cathode four times.
The reverse: Made in England and BVA.
The thin glass tube envelope is 18 mm in diameter and the length, excluding the B7G base pins, is 58 mm.
