The 8072 is a contact cooled beam power valve for use as a PA in low voltage mobile transmitters. The operating frequency is to 500 MHz. The screen grid connects to the outer ring. The average output power is 40 Watts and peak is 80 Watts.
The top cap and outer shell are both connected to the anode. A cooling block would be clamped to the shell and in turn connected to a heat sink.
The base. The multiple grid connections are approaching a co-axial construction.
The base showing pin heights.
The thin metal tube envelope is 21 mm in diameter, and excluding the special base pins is 48 mm tall.
Reference: Data-sheet. Type 8072 was first introduced in 1962.