The question of the relationship between the classes of Fedorchuk and Rosenthal compact spaces was first raised in 1992 by Watson. An example of a Rosenthal compact, which is not a Fedorchuk compact of countable spectral height, is the well-known Helly compact. It is shown here that there exist numerous examples of Fedorchuk compacta of spectral height 3 (among which there are perfectly normal compacta) that are not Rosenthal.