This double triode is a mystery. The pin connections match the ECC8x arrangement but there are no markings. The triode sections are not screened and so a general purpose or audio type is indicated. The sections are quite wide but the anodes have been left bright. One would expect the anodes to be black if considerable power was to be dissipated. The control grids are wound on copper supports.
The valve came from an audio amplifier and my guess is that it is close to the ECC82.
The next stage will be to put the valve on test.
The anodes are stitched together and the form is a central box with side flanges set at the points of maximum heat generation.
The ends of the anodes are open allowing the grid to be seen.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 49 mm tall.
