The 6EA8 is a triode pentode. This valve was made by Mullard in the UK for the American distributor IEC.
The pentode is of the sharp cut-off type. The design purpose was as a triode oscillator and pentode mixer within VHF TV tuners.
The warm-up time is 11 seconds and this valve would usually be found in a series heater chain.
The pentode (left) is mounted at right angles to the triode (right).
It is possible to see under the d of Mullard the end of the screen grid. The electrode for suppressing secondary emission is a beam plate that can be glimpsed inside the opening of the anode.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 48 mm tall.
Reference: Data-sheet. Type 6EA8 was first introduced in 1958. See also1958 adverts.
