The CV848 is a low power amplifier beam tetrode that features a low anode to cathode capacitance and has two small anode plates at a wide separation from the cathode. It can operate as an RF or IF amplifier with a maximum operating frequency of 400 MHz. The commercial Type designation is 6AG5.
The anode plates at each side, the beam plates seen bright in the centre and through the hole in the beam plate can be seen the two grids. The grids have been formed with sharp bends to achieve the correct distances and pass flat across the cathode.
This oblique view shows more of the geometry and also highlights the screening at the top.
The thin glass tube envelope is 18 mm in diameter and excluding the B7G base pins the valve is 46 mm long.