[evlatests] ea24 problem

[Ken Sowinski]

On Fri, 4 Mar 2011, Emmanuel Momjian wrote:

> Yesterday, test observations at Ku-band showed noisy phases and amplitudes
> on ea24. To look into this in more detail, today we ran multi-frequency
> observations spanning all the bands from X to Q using the calibrator
> J2202+4216 .
>
> While there is nothing obvious at X-band, the data show that the phases and
> the amplitudes degrade progressively from Ku to Q band.
>
> Pointing looks OK on ea24. Therefore we think that the problem may be in the
> L301 or its reference signal, although L302 and the round trip phase look
> good.

The problem was just found to be focus.  The focus zero point changed
by about 2 cm sometime last week.  I have adjusted the focus settings
for all the high frequency bands as well as X and C bands.  A more
careful measurement will be made in the next day or so.