[daip] Tsys for Y27

[Amy Mioduszewski]

This is just to get this in the daip archive in case we get questions.  I don't 
think there is anything that needs to be fixed.

I had VLBI data with Y27 that had no gain curve and the TANT column in the TY 
table did not contain -1 (-1 in the TANT column means that the number in the 
TSYS column are Tsys/Tant, which is the case for the phased VLA).  The missing 
GC table was the analysts fault for running their TY&GC creating scrips as 
"analysts" and not having the permission to write to the correct files.  This 
then caused the TY table to be incorrect because FITLD looks at the gain curve 
to determine if the observation was Y1 or Y27 and the default is Y1.  I could 
argue that the default should be Y27, but I don't think it is important enough 
to do anything about.  Pretty soon we won't have the VLA in VLBI experiments for 
a while and we don't know what things are going to look like when it comes back.

Amy