A, we hope, final version of TECOR is now available for the MNJ in 31DEC23, 31DEC22, and 31DEC21 versions of AIPS. Getting the ionosphere pierce point azimuth to be similar to the source azimuth was a bit more complicated than first realized. The latest AIPS Letter(s) are all available from http://www.aips.nrao.edu/ Cheers Eric Greisen