[evlatests] focus and antenna 14

[Ken Sowinski]

I verified that the methods put in place to deal with 
focus offsets and the focus-elevation curve seem to  work 
in a mechanical sense.  Both can be set and controlled from 
the observe script.

subarray.setFocusOffset() works like subarray.setAz/ElOffset(),
units are cm.  This can be used to implement a "focus finding
mode" analogous to the existing pointing modes.

subarray.setRefocus() works.  The parameter is 0, don't,
or 1, do refocus.  The coefficient of sin(El) comes from
the database, is band dependent, but the same for all antennas
at each band.  Currently X band is set to 0.55 cm and the rest 
are unset.  We should be in reasonable shape if values are entered 
for K and Q bands and the primary focus values for each antenna 
adjusted.  Once a focus finding mode, and a version of telcal that 
does focus are in place we can try an observation to measure the
focus curve.

Something funny happened to antenna 14.  Fiber to all antennas was
disconnected this morning, but antenna 14 did not come back properly.
That was traced to a known L305 problem at that antennas which requires
cycling power to the L305 to make it reacquire proper lock.  This was
done, and the antenna sort of returned.  The problem is that the 
delay changes for some IFs are much to large to be reasonable.
A -106 ns
B  -38
C    0
D  ???
The change in IF D was so large that I did not take the time to try
to find it.  If B, even with the -38 ns change is still down by about
a half in power compared to IFs A and C suggesting that there might
be something wrong with the BD IF pair.  The change to delays for IFs
A and B were made only for X band.  Is it possible there is still 
something not quire right in the DTS modules after all the resets done
today?