The CV5292 is a velocity modulated microwave oscillator or Heil tube. Heil tubes were made by STC. The magnets were external to the tube.
The CV5292 operated at between 3.555 GHz to 4.250 GHz.The Heil tube was used as a local oscillator in a receiver and the CV5292 could generate 550 mW - sufficient for a small transmitter at microwave frequencies.
The KB/F identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the F identifies the maker as STC, Paignton.
The heater wires can be seen near the top of the image.
The evacuation pip is on the side.
The valve was operated in a co-axial enclosure and the 41 mm diameter flange would be clamped to the enclosure.
The thin glass tube envelope is 19 mm in diameter and, excluding the B7G base pins, is 72 mm tall.
References: Data-sheet. Type CV5292 was first introduced in 1963. See also1963 adverts.
