The PCL83 is a television audio triode output pentode from the era of VHF television in the 1950s. It produces enough audio output power for an average domestic environment but was designed for frame timebase and frame output.
The pentode is on the left and the triode on the right.
Face view of the triode section.
The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins, is 48 mm tall.
References: Datasheet & 1040. Type PCL83 was first introduced in 1954.