The 117P7GT is an American audio beam tetrode and half wave rectifier for use in domestic radio receivers. The audio output is given as 850 mW and the rectifier has a maximum output current of 75 mA. The heater is designed to operate directly across the mains input without the need for a mains transformer.
The RCA name and logo,
The dome with oval cathode, two grid supports and the tags for the beam plates.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 68 mm tall.
Reference: Data-sheet. Type 117P7GT was first introduced in 1940. See also1940 adverts.