  As it is known, finitely presented quivers correspond to Dynkin graphs
(Gabriel, 1972) and tame quivers -- to extended Dynkin graphs (Donovan and
Freislich, Nazarova, 1973). In the article "Locally scalar reresentations of
graphs in the category of Hilbers spaces" (Func. Anal. and Appl., 2005) authors
showed the way to tranfer these results to Hilbert spaces, constructed Coxeter
functors and proved an analogue of Gabriel theorem fol locally scalar
(orthoscalar in the sequel) representations (up to the unitary equivalence).
The category of orthoscalar representations of a quiver can be considered as a
subcategory in the category of all representations (over a field $\mathbb C$).
In the present paper we study the connection between indecomposable orthoscalar
representations in the subcategory and in the category of all representations.
For the quivers, corresponded to extended Dynkin graphs, orthoscalar
representations which cannot be obtained from the simplest by Coxeter functors
(regular representations) are classified.
