The transport properties of sintered samples of Nd1
-xCaxBa2Cu3O7-d with 06x60:20 have been studied in the normal state by Hall resistivity measurements. The Hall coefficient,RH(x,T)was well described in terms of two different models. In a phenomenological narrow band model, the conduction band width became narrower with increasing Ca concentration while the density of states band width decreased slightly. A competition between two effects (i) added charge, and (ii) disorder introduced into the CuO2 planes by doping, could be the main reason for the observed small decrease of the band widths. In the Anderson model, the temperature dependent part of the Hall angle was independent of hole concentration and disorder while the temperature independent part increased linearly with increasing Ca content. The results in both models support that Ca introduces disorder in the CuO2 planes.

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