Checks are made to find out the stability of the telescope gain and phase offset. The mean telescope gain of every different 12 hour observation will be used as input parameter in the first part of the reduction-batch (wenssabp1). Also dipole errors and ellipticities are calculated which are needed for the polarization calibration. This step is done both for calibration observations before and after mosaic observations. This step will be important if we choose ``align'' instead of ``selfcal'' in wenssabp1 to correct the phases. It will also show whether there are any telescopes missing during the calibrator observation. If this is the case then this observation will not be used.