Type 6AN8A is a triode-pentode with a defined warm-up time for use on series heater chains. The pentode section is used as a video amplifier or reactance valve while the triode performs variously as a phase detector, gating valve, oscillator or phase splitter.
The Sylvania name. Seen beyond the side strap of the anode are the two central grids and the beam forming plates.
The small triode is full height and separated from the pentode by a bright electrostatic screen.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 47 mm tall.
References: Datasheet. Type 6AN8A was first introduced in 1954.