I saw on a datasheet for tubes, a PL36 vintage tube that I have, claims to be a 'Pentode' while when I look at the tube itself, it appears that it has a set of beam forming plates rather than a 3rd grid.
Also, with the 6L6GC, it commonly states that it is a Beam pentode, while in reality it is a Beam Tetrode.
Also, with the 6L6GC, it commonly states that it is a Beam pentode, while in reality it is a Beam Tetrode.