The CV2180 is a half wave rectifier based on the VX6095 and designed in the early 1960s. It is indirectly heated and uses a 2.5 Volt heater, the original American standard for AC heated valves.
The folded anode is made to have six spikes aound the central core to increase the radiating area for maximum cooling. The high voltage working, up to 20 kV PIV, requires a solid ceramic support for the electrodes.
The current rating is low and the heater wire is of small diameter..
The ceramic support mounted directly on the pinch. Note the anode folds and the central cylindrical working space.
This image shows the geometry very well. The heater is twisted within the cathode tube.
The thin glass tube envelope is mm in diameter, and excluding the base pins is mm tall.