Post-fit residual phase-delays for baselines Kitt Peak–Pie Town (left) and Hancock–Mauna Kea (right) for all observed sources: undifferenced delays (top); differenced delays (bottom). The dashed lines correspond to the delays of a ± 2π phase ambiguity at 43.1 GHz. Each color represents one source in the sample. The lack of residual differenced phase-delays between 20–25 h for the baseline HM is due to low S/N data of source 20 (magenta) in that interval.