[evlatests] 23aug06 AR603 runs: quick fringe checks

[Michael Rupen]

23aug06: AR603 (07:35-08:35, 11:39-13:34, 13:34-15:04 IAT)
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mpr 24aug06

Preliminary report -- quick fringe check

C & X bands, standard continuum, 3.3s averaging, mostly fast switching scans

Two dynamics followed by a regular run

EVLA ant. 13,14,16,18 included
   ***note ant. 18 not included in C-band-only run, with the comment that
     "C band is currently inoperative on this antenna."  In fact
     ant. 18 is among the best antennas in the array at C band!

* Both bands
   - EVLA-EVLA baselines are flagged badly, as described in 21aug06
     comments: for all but the 1st source in an fs scan, clearly off-source
     for 1st 1-2 records, then a 10s gap, then on and lookin' good
     (with the regular VLA antennas) thereafter

   - ant. 18, IFs BD show occasional 60 degree phase jumps, as on 24aug06,
     suggesting the L302 heartbeat problem.  IFs AC are OK.

* C band
   - ant. 18 backend Tsys are hooey -- reported absolutely constant at
     ridiculous values (3.0, 3.4 K) in all IFs.

   - 07:35-08:35: no fringes on any EVLA antenna during 1st fs scan
       fine on all antennas for calibrator (normal) scans thereafter

   - 11:39-13:34:
     : no fringes from ant. 18 through 12:33; then no data through the end of
       this run (13:34)
     : no fringes on any EVLA antenna during 1st fs scan
     : ok on 13,14,16 from then until 12:28 (calibrator [normal] scan)
       then no fringes until next calibrator (normal) scans at 12:58
       Then no fringes through another fs & normal scan, only to return
         for 0542+498 at 13:33.

   - 13:34-15:04 (regular run):
     : fine fringes throughout, on all EVLA antennas

* X band
   - ant. 13, 14, 16 look OK

   - ant. 18 had the usual high Tsys (100-150 K) and correspondingly noisy
     fringes

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