Amy, Jim, I think I averted the problem by copying my latest CL table (CL 3 -> CL 4) and running CLCAL with opcode 'CALI' and antenna -11,0 using my latest SN table + CL 3 and writing on CL4. I looks like antenna 11 is untouched in CL 4 and the correct solutions were passed for the other antennas. Does this sound kosher? Teddy