[evlatests] 8sep07 X band quick look

[Michael Rupen]

Project: AO224  fast-switching in standard X band continuum
                 3.3s integrations

          8sep07


Mostly this repeats Rick's summary at X band.

* Last record on last contiguous scan is unflagged but bad.  This
   is followed by 10s of "blanked" (on-line flagged) data, then another bad
   but unflagged record.

* EVLA ant. 11 IF AC shows Rick's "square wave" in phase, about 50d between
   the two states

* EVLA ant. 13: the first pair of scans are correctly flagged, as the
   amp. on the calibrator is very low and the phase is mostly but not
   entirely random.  This again is per Rick.  However, I did NOT see
   Rick's similar problem on ant. 19, IF A.

* EVLA ant. 14: shows a very fast phase wrap in the 2nd cal. scan
   (360d in one minute), on all IFs.  No other antenna shows this.
   There are also occasional phase jumps (all IFs jumping together).
   This *differs* from Rick's report (he found EVLA-14 to be completely
   unstable, on 10sep07).

* Ant. 15 (NOT an EVLA antenna): IF C is crazy (but unflagged) during
   the fast switching scan (constant phase on the undetected source, phase
   jumps every record on the calibrator, high and rapidly oscillating [period
   about 10s] amp.).  The "normal" scan on the flux cal. (3C48) is fine.
   Not reported by Rick.

* EVLA ant. 18: IFs AC show coordinated phase jumps in the first and
   last calibrator scans, but are otherwise fine.  This contrasts
   with Rick's 10sep07 report of square waves throughout.

* EVLA ant. 23 : IF C shows an abrupt drop in Tsys in the middle of a
   source scan (04:48:20), from ~57 K to ~55 K.  The amp. and phase
   look fine.

None of the above were reported in the log.

-- Michael --

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