The CV5077 is a PL81 in UK service form, physically it is identical to the PL81. It was designed for universal mains television sets, i.e. without a mains transformer and with the heaters on a series chain. Parameters given are for a pair in push pull audio service, but this was never the design use.
As a line output valve in monochrome television service, the design use, the peak anode surge voltage is 7,000 Volts. The anode dissipation is 8 Watts.
The Mullard later logo dating this valve to the 1970's.
The control grid copper supports connect to radiating fins above the top mica. The outer insulators are ceramic and within the anode can be seen the beam plate.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 73 mm tall.
