Abstract. Denote by µ a the distribution of the random sum (1 − a) ∞ j=0 ω j a j , where P(ω j = 0) = P(ω j = 1) = 1/2 and all the choices are independent. For 0 < a < 1/2, the measure µ a is supported on C a , the central Cantor set obtained by starting with the closed united interval, removing an open central interval of length (1 − 2a), and iterating this process inductively on each of the remaining intervals. We investigate the convolutions µ a * (µ b • S −1 λ ), where S λ (x) = λx is a rescaling map. We prove that if the ratio log b/ log a is irrational and λ = 0, thenwhere D denotes any of correlation, Hausdorff or packing dimension of a measure.We also show that, perhaps surprisingly, for uncountably many values of λ the convolution µ 1/4 * (µ 1/3 •S −1 λ ) is a singular measure, although dim H (C