This valve is a dual transmitting tetrode. The design is of the American type with two separate valves sealed into the single element. Additionally the valve is probably of American manufacture as the envelope bulge is characteristic. The oval cylinder anodes enclose the beam plates, grids and heater cathode assembly. This type of construction usually required external capacitors to neutralise parasitic oscillations. These normally being vertical wires alongside the envelope.
Most 832 and 832A valves, the commercial versions of the CV788, have plain glass for the base and top of the envelope. This exhibit like the Adzam 832A has a sintered glass base like the QQV03-20A. The sintered glass gives improved electrical properties.
This type of dual valve was obsolete by the start of the 1960s replaced by the QQV03-20 or QQV06-40A varieties. It is typical of these RF power tetrodes that the base connections all match one another. However, with the revival of valve audio in the 21st century the dual valve approach gives a clearer audio response probably as the design was based on the 6V6 originally. The European pattern QQV03-20A et al were designed from the start for Class C RF use or Class B modulators - not for music reproduction.
The oval anode with ceramic insulators at the top. The control grid head radiator is sited below the lower mica.
The sintered base.
The anode pins held in raised glass for greater support. The original 832 lacked the ceramic insulators and had a max anode voltage of 500 Volts. The A variant was uprated to use 600 Volts on the anodes by virtue of the extra insulation.
The wide glass tube envelope is 50 mm in diameter and, excluding the B7A base pins, is 69 mm tall.