CALIBRATEASTROMETRY: this is the first calibration step (of the $uv$-coordinates, that is) you should take. Here we examine the averaged delay data with PLOT (select FDL_O-C), before attempting to fit station coordinates with SOLVE. Note that FDL_O-C for the reference station is identical to zero by definition. (To change the reference station use the AstrometrySolution widget. The reference station is station 1 by default in the .con file.) Do not solve for star positions. (When the solution widget is displayed, the default settings do not need to be changed for this step.) Check the O-C values again and save the StationTable if you are happy with the fit. If for any reason there are outliers, try to locate and flag them in the corresponding point data, then average again.