Type 6N7 designed to operate in push-pull Class B2 with zero grid bias. The anode to anode load is given as 8,000 Ohm. It is specifically an audio power valve capable of 10W per pair. Provided plenty of HT voltage is available it can also be used, with both halves connected in parallel, Class A1, as a power driver for another 6N7.
Type 6A6 is the same valve but on a UX7 base.
The control grids have heat radiating fins at the top. The anodes have side flanges to increase their surface area.In this design the working faces of each section are parallel to each other so that both of the working faces are oriented to the glass envelope.
Looking along the axis of the grid winding.
The control grids are wound on copper supports for good heat transfer.
The wide glass tube envelope is 28 mm in diameter, and excluding the IO base pins, is 66 mm tall.
References: Datasheet, 1040 & 1043. Type 6N7GT was first introduced in 1936.