The intergranular coupling of the Cu0.5Tl0.5Ba2Ca2Cu0.5Zn2.5O10- superconductor has been studied by resistivity and AC magnetic susceptibility measurements. The main objective of the present study is to enhance the intergranular coupling of this compound by post-annealing the samples in nitrogen, oxygen and air atmospheres. Any improvement to the intergrain coupling may be promoted by a change of oxygen content in the final compound. The AC susceptibility measurements have shown that the intergranular coupling peak observed in the out-of-phase component ('') is shifted to higher temperatures after post-annealing in an air atmosphere, which is evidence of enhanced intergrain coupling promoted by oxygen diffusion. Enhanced intergranular coupling and flux pinning is observed in nitrogen and oxygen post-annealed samples in field AC susceptibility measurements.