Single crystals of Pb2Sr2R1-xCaxCu3O8+delta (R = Y, Tb) superconductor were grown from PbO-NaCl flux. The Ca content was determined by means of EDX method to vary in the range 0.3-0.5. The superconducting transition temperature was found to be close to the optimal value of 70-80 K. The intergrowths with another superconducting perovskite (Pb,Cu)Sr-2(Y,Ca)Cu2O7 of T-c approximate to 60K was observed for Y-based crystals, what resulted in a double transition observed frequently in magnetic measurements. This tendency has not been found for Tb-based crystals which usually showed more sharp transitions. Thermogravimetric experiments showed that the oxidation process of Pb2Sr2R1-xCaxCu3O8+delta single crystals proceeds in two steps. The first one corresponds to Cu1+ oxidation (500-550 degreesC for both R = Y and Tb), the second could be attributed to lead oxidation (830-870 degreesC for R = Y and 80-100 degreesC lower for Tb-based compound). (C) 2004 Elsevier B.V. All rights reserved.