each epoch and deconvolving the resulting image using a maximum entropy algorithm. From 1996 onwards, the source has been of sufficient signal-to-noise that phase self-calibration can be successfully applied to the data, resulting in a significant improvement in the accuracy of the complex gains for each antenna.

  ------------ ------------- -------- ------- ------------- ------------- ---------- --
   Mean Epoch    Observing     Day     Array   Frequencies     Time on      Radius   
                   Date       Number              (MHz)      Source (hr)    ($''$)   
     1992.9     1992 Oct 21    2068     6C      8640,8900        15        0.66(2)   
                1993 Jan 04    2142     6A      8640,8900        13        0.66(2)   
                1993 Jan 05    2143     6A      8640,8900         5        0.62(2)   
     1993.6     1993 Jun 24    2314     6C      8640,8900         9        0.62(1)   
                1993 Jul 01    2321     6C      8640,8900        10        0.68(1)   
                1993 Oct 15    2426     6A      8640,9024        18        0.69(1)   
     1994.4     1994 Feb 16    2550     6B      8640,9024         9        0.69(2)   
                1994 Jun 27    2683     6C      8640,9024        21        0.659(7)  
                1994 Jul 01    2687     6A      8640,9024        10        0.659(9)  
     1995.7     1995 Jul 24    3074     6C      8640,9024         7        0.687(8)  
                1995 Aug 29    3111     6D      8896,9152         7        0.69(2)   
                1995 Nov 06    3178     6A      8640,9024         9        0.685(6)  
     1996.7     1996 Jul 21    3437     6C      8640,9024        14        0.688(4)  
                1996 Sep 08    3486     6B      8640,9024        13        0.684(4)  
                1996 Oct 05    3512     6A      8896,9152         8        0.692(6)  
     1998.0     1997 Nov 11    3914     