The CV2194 is equivalent to the commercial G400/1K from STC. It is a high stability, high voltage, low current voltage stabiliser. The priming anode and actual anode are to be connected together in the external circuit.
The ceramic tube shields the anode lead and is cemented to the glass base.
The STC commercial identification on the other side of the envelope. The CV designation could possibly have been overprinted after manufacture.
The construction looks to be a series of vertical plates with the anode being a thin strip with the priming anode placed between the anode and the cathode. The priming anode has a central slit that the anode sits behind. The plates are held in place with insulated rods in the four corners. This precise control of the geometry is to give precision to the discharge voltage.
The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins is 46 mm tall.
Reference: Data-sheet. Type CV2194 was first introduced in 1959. See also1959 adverts.
