[evlatests] antenna 18 works

[Ken Sowinski]

> Despite the winds we are now doing pointing to make the antenna
> more useful in the short term.  Later I will try to optimize focus.

Both these have now been done.  Given the wind only the
change in El collimation looks significant; it was changed
by -0.8 arc-min.  Focus was examined and a reasonable setting
is 3.5 cm.  Both these changes have been made in the data base.

A long scan was started at 2233 IAT on #C84 with 14, 16 and 18.
Antenna 13 seems not to be available today.  It ended at 2308.
A more careful comparison with other EVLA and VLa antennas
might be a good thing.

I have encouraged the operator to include antenna 13 (which is
on the master pad) in the baseline run scheduled for tonight.