The 9A8 is from the era of VHF television in the 1950s and early 1960s. The valve is a triode pentode with separate cathodes, designed to function as a mixer and oscillator in the tuner front end.
The bright screen separates the two sections with the triode on the right. The triode has copper grid supports.
Face view of the triode with stitched anode. The screen is larger in size than the triode to screen it completely.
The pentode section.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 48 mm tall.
