Spectroscopic studies of weakly populated proton i(13/2) bands in superdefo
rmed Tl nuclei (around mass 190) and in the normally deformed, very light T
l-183 nucleus are discussed. Among the results presented, the first measure
ment of a superdeformed quadrupole moment in an odd-Z nucleus, Tl-191, is r
eported. The experiments were conducted with the Gammasphere array as "stan
d-alone" device and coupled with the Argonne Fragment Mass Analyzer.