The 5675 is a microwave disc seal triode. The device is physically small, coaxially designed and connections are brought out to connections along the body of the valve so as to better locate the valve within a resonant cavity. The cathode connection is made via a spring clip that fits over the metal body.
The valve is rated for high altitude use and for use as a Class C amplifier and oscillator at up to 1.7 GHz.
The cathode is on the right and can be seen as a dark rod entering the central grid. The anode is bright and on the left approaching the grid. The grid is a cage that enters the anode with the cathode tube inside. The enhanced 5675A has a copper anode for faster heat transfer.
On the left of the central disk is a dark area with black lines this is the grid.
This exhibit was donated by Joe G3LLV.
The thin metal tube envelope is 6.3 mm in diameter and, excluding the base pins, is 54 mm tall. The grid ring is 20 mm in diameter.
Reference: Datasheet. Type 5675 was first introduced in 1954.