Delays should be checked after antenna moves or cable changes. You can estimate the magnitude of the delay errors present by looking at the spectrum of a continuum source.
Any phase slopes across the band e.g. winding, are indications of a delay offset problem.
Baselines should be looked at individually, do not average baselines when looking for phase slopes. A phase slope of 180 degrees across the band corresponds to a delay error of one delay-step. 2.5 nsec of the correct value, skip step 2 and go to step 3. This takes about 30 minutes. If you cancel the schedule file while it is running, the delay offset for antenna 1 will remain non-zero.