The CV485 is a Heil Tube. Named after its German inventor, the Heil tube is a velocity modulated oscillator. Unlike the klystron the electron beam in the Heil tube is focused by an external magnet.
The commercial valve is the V246A/1K and the CV485 is a selected variant with the bulk production known as the CV228 and the CV specification sheet confirms this.
The CV485 is operated at 40 mA cathode current and produces 0.25 W at 4580-4860 MHz. The copper disc is internally connected to the resonator at pin 6.
The envelope has the words Nov 1963 on it thus dating this exhibit.
The copper disc is used to mount the valve into its resonant cavity. The locating holes in the disc preserve alignment to the magnet when valves are changed.
The electron source is at the top and the anode at the bottom of the image. The electron beam passes through the resonator tube where the electron beam bunches.
The thin glass tube envelope is 19 mm in diameter, and excluding the B7G base pins is 75 mm tall.
Reference: Data-sheet. Type CV485 was first introduced in 1957. See also1957 adverts.
