The GE15371 is a planar triode designed for use as a pulse oscillator at 1.09GHz. At a pulse width of 1μS, repeated at 1,000 pulses per second the pulse output power is up to 700 Watts.
The Type designation on the base. The connections are gold plated and the base has the heater contacts.
The anode is the top cap. The grid is the ring closest to the anode and the cathode is closest to the base.
The thin ceramic tube envelope is 15 mm in diameter, and excluding the base pins is 20 mm tall.
Reference: Data-sheet. Type GE15371 was first introduced in 1970. See also1970 adverts.