[evlatests] comments on ea21, ea28

[Ken Sowinski]

ea21 received a new C band receiver some weeks ago, but never
had the BD attenuator table values updated.  This was done
today.  We need a more robust system to be sure that operations
is aware of a receiver swap, and knows that attenuator settings
should be checked after the receiver is cooled and stable.

The pointing for ea28 may have been straightened out today.
the servo group went at it again this morning and a 3 dB
tracking test during lunch proved it to be no worse than any
of the other antennas on a windy day.  If a pointing run tonight
bears out that statement, we might have an operational antenna.