[mmaimcal] other effects

[Harvey Liszt]

The point is that we really can't allow any phase gradients or other
structure across the main beam, or the 0.7" pointing error will begin
to be important at short wavelengths.  Short then really means where
we begin to realize that we're using a non-ideal instrument to do the
observing, or  where the shape, alignment, deformation, and other aspects
of the mechanical structure become noticeable.

regards, Harvey