[evlatests] ea28 pointing

[Ken Sowinski]

On Fri, 7 Nov 2008, Ken Sowinski wrote:

> On Mon, 3 Nov 2008, Ken Sowinski wrote:
>
>> The pointing solution is poor and many trials were rejected for
>> having too large an estimated beamwidth.  Steve reported this
>> morning that there may still be some ACU problems.  If that is
>> so, a high quality pointing run awaits the resolution of that
>> problem.
>
> This has finally been attributed to a large periodic encoder
> error.  It will be adjusted today and if a pointing run over
> the weekend is successful the antenna may be moved next week.

The pointing run showed that antenna 28 was not improved at all.
Either the antenna points erratically for yet undiscovered 
reasons, or it has a system problem which causes amplitude
fluctations which disturb the pointing trials.

There are two simple things that can be done.
1.  Another 3 dB tracking test to be sure that was really fixed.
2.  A long track on a bright source to probe stability.

I expect to have both of these done tonight so that we can
examine the results on Monday.