The 6W6GT is a beam tetrode with an an ode dissipation of 7 Watts. The design use was for vertical amplification in 525 line 30 frame TV receivers. The alternate use was as a Class A audio amplifier. At 10% THD the 6W6GT could produce 3.8 Watts.
The xW6GT family also included the 12W6GT with a 12.6 Volt heater and 25W6GT with a 300 mAheater running at 25 Volts.
The anode end seam. The top mica is a tight fight to the glass envelope.
Face view of the anode. The thin nickel sheet is ribbed to add rigidity.
The top mica showing the rectangular cathode, supports for the two inner grids and the tab at the top of the beam plates.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 73 mm tall.
References: Data-sheet & Data. Type 6W6GT was first introduced in 1939. See also1939 adverts.